explain xkcd - User contributions [en]

2982: Water Filtration

2024-09-09T14:52:48Z

162.158.154.241: Added that the synthesis of water pictured involves subatomic as well as atomic aspects.

{{comic
| number = 2982
| date = September 6, 2024
| title = Water Filtration
| image = water_filtration_2x.png
| imagesize = 593x467px
| noexpand = true
| titletext = You'd think the most expensive part would be the quark-gluon plasma chamber, but it's actually usually the tube to the top of the atmosphere to carry the cosmic rays down.
}}

==Explanation==
{{incomplete|Created by WATER. JUST PLAIN WATER. NOTHING DONE TO IT, JUST PLAIN WATER. POSSIBLY DRINKABLE. - Do NOT <s>drink the water</s> delete this tag too soon.}}
This comic seems to be a diagram of how well water is purified, a common procedure done to make said water safe to drink. However, this well water is "purified" through a series of increasingly unnecessary, expensive, and possibly hazardous steps, ending with producing "pure" water synthesized from hydrogen and oxygen (which have each been synthesized from subatomic particles) - before promptly undoing most of the work by re-adding raw well water, along with minerals and probiotics "for taste and to support immune health".

{| class="wikitable"
|-
!Step
!Real Device?
!Used for water purification?
!Explanation
|-
|Water softener
|{{Yes|Real}}
|{{Yes}}
|{{w|Water softening}} is the removal of calcium, magnesium, and certain other metal cations in hard water. The resulting soft water requires less soap for the same cleaning effort, as soap is not wasted bonding with calcium ions. Soft water also extends the lifetime of plumbing by reducing or eliminating scale build-up in pipes and fittings. The comic shows the water either being passed through some granulated material (presumably, {{w|ion-exchange resins}}) or into a precipitation chamber for lime (or soda ash) softening.
|-
|Reverse osmosis
|{{Yes|Real}}
|{{Yes}}
|{{w|Reverse osmosis}} is a common step used in modern water-purification systems. It relies on using osmotic membranes and high pressures to separate water molecules from dissolved solutes and biological substances. Interestingly, it would also act as a softening step, rendering the previous step potentially redundant, depending on the goals for each step. It's also overkill for most wells, as groundwater often needs treatment targeted to only a few contaminants, if any treatment at all.
|-
|Ultraviolet Sterilization
|{{Yes|Real}}
|{{Yes}}
|{{w|Ultraviolet germicidal irradiation|Ultraviolet sterilization}} uses UV lamps at short wavelengths to damage the DNA and thereby kill micro-organisms in the water. In the USA, this is an unlikely method of well water sterilization, as the pathogens most likely to be found in well water (as opposed to surface water) are generally much more responsive to chemical disinfection. Many wells don't even need a disinfection step; whether this well needs disinfection or not, this is hardly the most impractical step in this treatment train.
|-
|Autoclave
|{{Yes|Real}}
|{{Yes}}
|{{w|Autoclaves}} are essentially large pressure cookers that sterilize items and liquids through exposing them to a high temperature (~120°C or ~248°F) over tens of minutes in presence of water. By maintaining a high pressure, the boiling point of water goes up. This creates a very hot and humid atmosphere, making efficient heat transfer with all contents and inactivating all biological entities through this heat. They are commonly used in hospital and laboratory settings to sterilize plastics, glassware, equipment and solutions (like bottles of growth medium for bacteria) to be used in a sterile environment. The advantage of this method compared to dry heat (aka putting things in a 150°C-180°C oven until they are sterile) is that most lab plastics survive a passage at 120°C without melting. While difficult to streamline (as this technique is used for batches), it has the advantage over light-based methods that heat gets everywhere, and that instead of just damaging DNA, you also denature the proteins and other structures of microorganisms.
|-
|Condenser
|{{Yes|Real}}
|{{Yes}}
|This step condenses the steam generated by the autoclave back into water. This is a normal part of the process used in "traditional" water purification by distillation.
|-
|Regular osmosis
|{{Yes|Real}}
|{{No}}
|Regular osmosis (also known as "osmosis") is the tendency of a solvent (like water) to flow through a semipermeable membrane towards the side that has a higher concentration of dissolved molecules or ions. Since the water is already highly purified at this point, osmosis would only work if the output water is ''less'' pure, adding dissolved substances to it.
|-
|X-Ray Sterilization
|{{Yes|Real}}
|{{No}}
|While {{w|Sterilization_(microbiology)#Ionizing_radiation_sterilization|x-ray sterilization}} is used to sterilize equipment, it is not normally used for water.
|-
|Carbon Filter
|{{No|Fake}}
|{{No}}
|The water is passed through some volume of carbon - a riff on activated carbon filters, which ''are'' used in water filtration as seen later in the process.
|-
|Neutron Source
|{{Yes|Real}}
|{{No}}
|A {{w|neutron source}} generates high-energy neutrons. High-energy neutrons are highly penetrating and will cause ionization events to occur due to collision with atoms in the water. This can potentially make the water more radioactive due to the generation of radioactive isotopes.
|-
|Activated Carbon Filter
|{{Yes|Real}}
|{{Yes}}
|{{w|Activated carbon}} is a form of carbon commonly used to filter contaminants from water and air, as it has a large surface area available to adsorb impurities on its surface. While this isn't a strange step to see in a water purification process, Randall makes a pun here with its proximity to the neutron source - the carbon has been '{{w|Neutron activation|activated}}' by the neutron source, and is currently radioactive. Water filtered through this may pick up radioactive isotopes from the filter.
|-
|Gamma Ray Sterilization
|{{Yes|Real}}
|{{No}}
|Similar to x-ray sterilization, this step uses {{w|Sterilization (microbiology)#Ionizing radiation sterilization|gamma rays}} to sterilize the water. Gamma rays can potentially irradiate the water through photodisintegration if their energy is higher than the binding energy of oxygen.
|-
|Cosmic Ray Sterilization
|{{No|Fake}}
|{{No}}
|Similar to the previous step, but this time using high energy {{w|cosmic rays}} to do so. This would be incredibly impractical, as cosmic rays are generally blocked by the atmosphere at high altitudes (as stated in the title text). Furthermore, their extremely high energy (shown to be in the exa-electron volt (EeV, or 1018 eV) range) would cause multiple high-energy particles to be created on impact with the water molecules, irradiating the water significantly.
|-
|Electrolysis
|{{Yes|Real}}
|{{No}}
|The water is broken down into hydrogen and oxygen gas using an electric current. Assuming the gas outputs of this process are pure hydrogen and oxygen gas, this *would* be an extremely effective sterilization tactic, seeing as no known organism or water pollutant is entirely composed out of hydrogen or oxygen gas. Along with the next step, this step may be a misguided attempt to "take the water apart and clean each part individually". The hydrogen is sent to the ionizer, while the oxygen is sent to the oxygen spallation step.
|-
|Oxygen Spallation
|{{No|Fake}}
|{{No}}
|Almost all oxygen in existence was originally created via {{w|stellar nucleosynthesis}}. Now, in this step in the purification, the oxygen is apparently broken down back into hydrogen via a fictional form of {{w|Cosmic_ray_spallation|spallation}}. While spallation can form lighter nuclei from heavier ones, there is no known process to convert oxygen back down to hydrogen. It is unclear what happens to the neutrons present in the oxygen nuclei - whether they are removed, used to create hydrogen isotopes or allowed to decay into protons and electrons (the components of yet more hydrogen, when properly reintroduced). The hydrogen formed here is merged with the rest of the hydrogen before being sent to the ionizer.
|-
|Ionizer
|{{Yes|Real}}
|{{No}}
|The hydrogen output by the previous step is made into a plasma with free electrons and protons (not bound into atoms).
|-
|Quark-Gluon Plasma Chamber
|{{No|Fake}}
|{{No}}
|The plasma output from the previous step is further energized into a {{w|quark–gluon plasma}}, such as the one found just after the Big Bang. This follows the theme of the previous steps, which all serve to break the water down into their elementary components. The incredible energies involved in doing so are unachievable by current technologies (current particle accelerators can form such a plasma for very short periods of time and involve a very small amount of matter), and serve to highlight the impracticality of this setup (as alluded to in the title text). The energies would also result in formation of lepton pairs from energy, which is presumably where the electrons from the previous step ended up.
|-
|Hydrogenation
|style="background:#FFFF9E;vertical-align:middle;text-align:{{{align|center}}};{{{style|}}}" class="table-yes"|Kinda
|{{No}}
|This process converts the quark-gluon plasma output in the previous step into elemental hydrogen, reversing the previous two steps. Presumably, this is done via {{w|hadronization}} and {{w|recombination}}; however, it is unclear how the {{w|baryon asymmetry}} needed to generate matter and not anti-matter is developed. The resulting hydrogen is split into 2 streams leading into the Nucleosynthesis and Reverse Electrolysis steps. In real life, {{w|hydrogenation}} is the process of adding hydrogen to unsaturated hydrocarbons.
|-
|Nucleosynthesis
|{{No|Fake}}
|{{No}}
|Part of the hydrogen produced in the previous step is converted into oxygen via 2 sub-processes. The hydrogen is first converted into helium and carbon through a combination of the {{w|proton-proton chain}} and the {{w|CNO cycle}} as per the labels on the step. The helium and carbon are then converted into oxygen through the {{w|alpha process}}. This step may also involve the {{w|triple-alpha process}}, seeing that the alpha process is typically only applicable to converting carbon into heavier elements owing to the lack of a stable element with eight nucleons. These steps normally occur in the cores of massive stars. It is not known how the oxygen is filtered from the extremely hot plasma of fusion products.
|-
|Reverse Electrolysis
|{{Yes|Real}}
|{{No}}
|This step is essentially a fuel cell, utilizing an electrochemical reaction to convert hydrogen and oxygen back into water and electricity.
|-
|Adding Well Water
|{{Yes|Real}}
|{{Yes}}
|A second pipe is linked to the first that simply feeds untreated well water into the pipes, partially undoing the entire process. Even if the well water is only a small portion of the faucet water, its presence has now made the now incredibly pure water impure. This act of putting well water into the faucet after treating it may be a riff on the cultural interest in "spring water" or "pure glacial water" that is said to have additional minerals or beneficial properties but is oftentimes not meaningfully distinct from properly treated tap water. "Local minerals and probiotics added" may be a reference to Coke's "Dasani" brand drinking water, which is purified by reverse osmosis, and then has a package of minerals added to create the flavor (pure water's actual lack of flavor can be perceived as an unpleasantly 'flat' flavor).

In addition, drinking only {{w|Tonicity|extremely hypotonic}} liquid intake can induce the body to expel more water than it took in (taking with it some essential minerals that are not being replaced) to try to maintain equilibrium of concentrations. This effect is not directly dangerous, but could exacerbate other bodily deficiencies in the long term and have the issues of greater than necessary liquid throughput than with 'normal' drinking water. The tendency for {{w|Sports drink#Categories|many 'sports' or 'health' drinks}} to hype the term 'isotonic' is based upon the idea that an ideal concentration of solutes can be added, in-between the opposing problems of having either too many ''or'' too few 'impurities'. The process does not include adding untreated (and probably also untested/unquantified) ground water, which could carry pathogenic organisms and chemicals, and appears to have no mechanism for ensuring what ''might'' be an acceptable level of re-blending for the circumstances.

Alternatively, it may be that the level of purity achieved by this setup is so overkill, and the cost per liter processed so high, that it's simply more efficient to treat just enough of the water to dilute the rest of the water to acceptable levels of contaminants. For example, it's common to use a partial bypass to supply water to the shower, since shower water does not need to be potable. Also, some well water systems are clean enough to not need any treatment at all and can be used straight from the well, and some water systems are only slightly high in a single chemical contaminant that can be addressed by blending the water, either with treated water or another source (treated or untreated). Perhaps the treatment process led to enough radioactivity that blending with the original source was required to address radiological contamination (either gross alpha radiation or specific radionuclides).
|}

The title text briefly covers the cost implications of the components. Various 'real' filter elements will have material or energy costs or both, in operation or to replenish their effectiveness, and the high energy input needed to disassociate hadrons into raw quark–gluon plasma (at bulk levels) would seem to require the most in terms of running the equipment. But it is pointed out that to ''ensure'' enough cosmic rays reach that particular phase of sterilization, there would have to be a pipe (not shown) leading out to the edge of the atmosphere to optimistically carry down such particles (due to also containing ''no'' air, i.e., keeping it out to negate the normal {{w|Air shower (physics)|shielding and dissipating effect}} of the atmosphere on cosmic rays).

Whether a one-off cost or needing regular replacement, the setting up of such a tubular structure (a vertical air-proof pipe perhaps somewhere between 100 and 10000 kilometers high) would be technically challenging and has not ever been actually accomplished. The conditions for a quark–gluon plasma, albeit in limited quantities, at least have been fulfilled at {{w|CERN}}, with its 27 kilometer airless pipe that goes round within a vast circular tunnel.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Header:]
:How Water Filtration Works

:[A system of various devices between water pipes is shown.]
:[Input:]
:Well water
:[Labels of various devices:]
:Water softener
:Reverse osmosis
:Ultraviolet sterilization
:Autoclave
:Condenser
:Regular osmosis
:X-ray sterilization
:Carbon filter
:Neutron source
:Activated carbon filter
:Gamma ray sterilization
:Cosmic ray sterilization [On the device: "EeV γ"]
:Electrolysis [H2O split into O and H]
:Oxygen spallation [O becomes H]
:Ionizer [H split into + and -]
:Quark-gluon plasma chamber [+ and - become QGP]
:Hydrogenation [QGP becomes H]
:Nucleosynthesis [H goes through "P-P CNO" and becomes He and C, then through "Alpha" and becomes O]
:Reverse electrolysis
:[Output after devices:]
:Pure water
:[Second input, mixed with pure water:]
:Well water
:[Label:]
:Local minerals and probiotics added for taste and to support immune health
:[Final output:]
:To faucet

{{comic discussion}}

[[Category:Chemistry]]
[[Category:Physics]]

2929: Good and Bad Ideas

2024-05-07T06:46:15Z

162.158.154.241:

{{comic
| number = 2929
| date = May 6, 2024
| title = Good and Bad Ideas
| image = good_and_bad_ideas_2x.png
| imagesize = 595x522px
| noexpand = true
| titletext = While it seemed like a fun prank at the time, I realize my prank fire extinguishers full of leaded gasoline were a mistake.
}}

==Explanation==
{{incomplete|Created by a BLOOD FOR THE BLOOD GOD- Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This is a scatter plot comparing how good an idea sounds to how good the idea actually is. For example, leaded gasoline sounds like a good idea due to the anti-knocking effects, but is actually a bad idea due to lead toxicity. Fake prank fire extinguishers however sound bad and are bad as they can result in a dangerous situation in an emergency. Putting mold on infections sounds like a bad idea, but this could be referring to Penicillin, an antibiotic.

The title text combines leaded gasoline and a fake prank fire extinguisher into something that is worse than either. Not only is the fire extinguisher fake, it also releases flammable material onto the fire, and there is the additional lead toxicity.

{| class="wikitable"
|-
! Idea !! What it means !! How good it sounds !! How good it actually is !! Explanation
|-
|Leaded Gasoline||Adding tetraethyl lead to gasoline to increase performance||++||---||Lead is toxic. Burning the leaded gasoline in an engine releases the lead in the air. This is bad.
|-
|Bloodletting||Releasing "bad blood" from the veins||---||---||You need your blood.{{Citation needed}}
|-
|Asbestos||Mineral which does not burn and is good isolation||+++||---||Asbestos was used extensively. Sadly the microscopic fibers which make up asbestos greatly increase the risk of cancer when inhaled.
|-
|Extension cords with prongs on both ends||||0 (neutral)||---||Prongs on both ends would make it easier to plug the extension cord in on either side. But once plugged into an outlet, the other end becomes a serious shock hazard.
|-
|Stair Kayaking||||||||
|-
|Fake prank fire extinguishers||||||||
|-
|Always saying what you think||||||||
|-
|Replying to spammers||||||||
|-
|Solar cars||||||||
|-
|Heelies||||||||
|-
|Prequels||||||||
|-
|Transition Lenses||||||||
|-
|Cutting pizza in squares||||||||
|-
|Project Orion||||||||
|-
|Combo washer dryers||||||||
|-
|Cutting sandwiches diagonally||||||||
|-
|Diverging diamond interchanges||||||||
|-
|Toasting sandwiches||||||||
|-
|Crumple zones||||||||
|-
|Sliced bread||||||||
|-
|Pizza||||||||
|-
|Eating citrus fruit while at sea||||0 (neutral)||+++||The vitamin C present in citrus fruits prevents one from contracting {{w|Scurvy|scurvy}}.
|-
|Putting mold on infections||||||||
|-
|Wheels on luggage||||||||
|-
|Heat pumps||||||||
|-
|Laser eye surgery||||||||
|-
|Fecal transplants||||||||
|-
|}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

{{comic discussion}}

Talk:2262: Parker Solar Probe

2020-02-01T16:46:11Z

162.158.154.241: Tyop and, punctuation...

I thought "down" meant towards the center of the Earth. Apparently I was wrong. [[Special:Contributions/162.158.214.148|162.158.214.148]] 23:17, 31 January 2020 (UTC)
:Our usual understanding of "down" means "towards the center of the Earth", here Randall is using it as "towards the center of the Sun". If you think about it, down means "towards the pull of gravity", Randall is just changing the gravity source he's referencing. :) [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 05:16, 1 February 2020 (UTC)

I think the reference frame used here is a reference to "the enemy's gate is down" from ''Ender's Game'', which is a book that the comic references often. [[Special:Contributions/172.69.69.238|172.69.69.238]] 23:57, 31 January 2020 (UTC)
:No, see my above comment. :) [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 05:16, 1 February 2020 (UTC)

Cueball and Megan standing on Earth remind me of the illustrations from {{w|The Little Prince}}. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 00:16, 1 February 2020 (UTC)

Whether or not the use is 'official', I can't help feeling that describing it as a "robotic" probe gives a different impression to some other term such as "(semi-?)autonomous". At the moment it makes me think of VINCENT from {{w|The Black Hole}} (*surely it can't be too long before the Disney trend to re-release "Live Action" remakes of its old features starts to include this, ''The Computer Wore Tennis Shoes'', ''Blackbeard's Ghost'' and ''Herbie Goes Bananas'' - jus' sayin' in passin'...) or Huey/Louie/Dewey from {{w|Silent Running|The Valley Forge}}. But I must check to see how much actuator use it has, other than for once-only 'deployment' like unfolding of solar panels/shielding. [[Special:Contributions/162.158.154.241|162.158.154.241]] 16:44, 1 February 2020 (UTC)

Talk:2262: Parker Solar Probe

2020-02-01T16:44:24Z

162.158.154.241:

I thought "down" meant towards the center of the Earth. Apparently I was wrong. [[Special:Contributions/162.158.214.148|162.158.214.148]] 23:17, 31 January 2020 (UTC)
:Our usual understanding of "down" means "towards the center of the Earth", here Randall is using it as "towards the center of the Sun". If you think about it, down means "towards the pull of gravity", Randall is just changing the gravity source he's referencing. :) [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 05:16, 1 February 2020 (UTC)

I think the reference frame used here is a reference to "the enemy's gate is down" from ''Ender's Game'', which is a book that the comic references often. [[Special:Contributions/172.69.69.238|172.69.69.238]] 23:57, 31 January 2020 (UTC)
:No, see my above comment. :) [[User:NiceGuy1|NiceGuy1]] ([[User talk:NiceGuy1|talk]]) 05:16, 1 February 2020 (UTC)

Cueball and Megan standing on Earth remind me of the illustrations from {{w|The Little Prince}}. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 00:16, 1 February 2020 (UTC)

Whether or not the use is 'official', I can't help feeling that describing it is a "robotic" probe gives a different impression to some other term such as "(semi-?)autonomous". At the moment it makes me think of VINCENT from {{w|The Black Hole}} (*surely it can't be too long before the Disney trend to re-release "Live Action" remakes of its old features starts to include this, ''The Computer Wore Tennis Shoes'', ''Blackbeard's Ghost'' and ''Herbie Goes Bananas'' - jus' sayin' in passin'...) or Huey/Louie/Dewey from {{w|Silent Running|The Valley Forge}}. But I must check to see how much actuator use it has, other than for once-only 'deployment', like unfolding of solar panels/shielding. [[Special:Contributions/162.158.154.241|162.158.154.241]] 16:44, 1 February 2020 (UTC)

2261: Worst Thing That Could Happen

2020-01-29T18:40:41Z

162.158.154.241:

{{comic
| number = 2261
| date = January 29, 2020
| title = Worst Thing That Could Happen
| image = worst_thing_that_could_happen.png
| titletext = Before I install any patch, I always open the patch notes and Ctrl-F for 'supervolcano', 'seagull', and 'garbage disposal', just to be safe.
}}

==Explanation==
{{incomplete|Created by THE WORST THING THAT COULD HAPPEN. Should discuss said worst things. Do NOT delete this tag too soon.}}

The punch line here is that when [[Ponytail]] asks what "the worst thing that could happen" is, everyone else answers with their ideas for the worst things that could happen ''ever'', not "...as a result of the upgrade", as Ponytail meant (shown by her facepalming in the last panel).
Alternatively, she could be facepalming at the fact that the worst thing which could happen, according to her team, is that they are put on a ridiculously gameshow in which, if they answer an incorrect question, they are chucked in garbage disposal. This may be bad, but it is nowhere near as bad as a supervolcano or nuclear war.

The title text talks about searching for a few of the things listed above, but one of them is 'garbage disposal', which could be confused with garbage collection (a programming term).

==Transcript==

[Ponytail is standing in front of a desk with a computer. Cueball, Harry, and Megan are standing behind her.

:Ponytail: We should upgrade. What's the worst that could happen?
:Cueball: Supervolcano.
:Harry: Robot uprising.
:Megan: Everyone falls down a well at once.

[Focus on Cueball, Harry, and Megan.]

:Cueball: Instead of hitting the tallest thing around, lightning starts hitting the nicest.
:Megan: Seagulls all get handguns.
:Harry: A really ''slow'' nuclear war.

[All back in focus. Ponytail is facepalming.]

:Cueball: We all have to go on a game show where they show you photos of people you've met once and ask you their names, and if you get one wrong a trapdoor opens and you fall into a garbage disposal.
:Harry: Ooh, that's a good one.
:Megan: Yeah, let's put off the upgrade.

{{comic discussion}}

2259: Networking Problems

2020-01-24T21:11:49Z

162.158.154.241:

{{comic
| number = 2259
| date = January 24, 2020
| title = Networking Problems
| image = networking_problems.png
| titletext = LOOK, THE LATENCY FALLS EVERY TIME YOU CLAP YOUR HANDS AND SAY YOU BELIEVE
}}

==Explanation==
{{incomplete|Created by an ODD-NUMBERED PACKET CLAPPING ITS HANDS. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}

Computer problems are frequent and can be difficult to solve. Networking problems in particular can puzzle even seasoned people and sometimes seem to have arbitrary issues causing them. Just to start with, your ISP may be engaged in traffic shaping, which can do very weird things indeed to your packets--making the first megabyte of a transfer faster than any other, for example; now imagine that your ISP's ISP is engaged in something similar, and you begin to see the scale of the problem.

The title text continue Cueball's maniacal attempts at self-assurance, with him alluding to James Barrie's ''Peter Pan'' by saying that latency falls every time you "CLAP YOUR HANDS AND SAY YOU BELIEVE". Ghosts generally are not concerned with expressions of belief, but there are some religious traditions that include group clapping and chanting. Many works of fiction depict a future or alternate history where {{tvtropes|MachineWorship|machines are worshiped as gods or spirits}}, such as the Adeptus Mechanicus of ''{{w|Warhammer 40,000}}''. Some of this terminology can be found in present-day IT and other support personnel, including references to "{{w|Daemon (computing)|daemons}}" and "[http://catb.org/jargon/html/B/black-magic.html black magic]". The statement of belief in ghosts may be a reference to the intermittent or fluctuating nature of the network issues being caused by mischievous spirits or malevalent poltergeists.

A more mundane explanation might be that there is a loose connection or trace, and the vibration of clapping and speaking in the vicinity of the equipment in question closes the connection.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

[Title: Types of Computer Problems]

[Subtitle: By how much debugging them makes your brain stop working]

[A number line reads "None", "Some", "A Lot", with an arrow continuing to the right.]

[A cloud labeled "Normal Problems" encompasses the region of "None" to "Some".]

[A cloud labeled "Networking Problems" in the region of "A Lot" and beyond.]

[Cueball is kneeling before a rack of servers. One of the server blades is extended and connected by a cable to a laptop sitting on a box, which Cueball is using. Behind Cueball, there is a wireless router sitting on a stool, which is connected by a cable to another wireless router sitting on the floor, which is connected to another laptop.]

:Cueball: '''''Before''''' noon, '''''odd'''''-numbered packets were laggy, but ''after'' noon, '''''even'''''-numbered ones are! It's the '''''opposite''''' of yesterday!
:Off-panel voice: Are you sure you're okay?
:Cueball: '''''I'm fine and I believe in ghosts now!'''''

{{comic discussion}}

Talk:2204: Ksp 2

2019-09-19T15:53:59Z

162.158.154.241:

Can someone create a KSP category? I don't have the rights to do that. Comics for that category include this one, [[1356:_Orbital_Mechanics]], [[1350:_Lorenz]], [[1244: Six Words]], [[1106: ADD]]. There may be others as well. [[Special:Contributions/172.68.211.184|172.68.211.184]] 18:05, 18 September 2019 (UTC)
:Yes I have done so: [[:Category:Kerbal Space Program]]. And found three more for a total of 8. Also a couple that "may" be a reference, but those I have not included. Just did a Kerbal search... --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 11:36, 19 September 2019 (UTC)

In the explanation, I took the "Unmarked Cash Payments" to be payoffs to the KSP2 team to delay their launch. [[User:OhFFS|OhFFS]] ([[User talk:OhFFS|talk]]) 18:07, 18 September 2019 (UTC)
: Hmm, that could be true too. Feel free to modify the explanation to add that. [[Special:Contributions/172.69.33.11|172.69.33.11]] 18:18, 18 September 2019 (UTC)

Are NASA engineers here splitting their time between working for both NASA and the KSP team (as suggested by the current explanation, as in ''actual'' 'moonlighting') or is it just that they're the kind of people who may 'catch' 24-hour flu to cover up their over-use of personal time to just enjoy the release as per all the other potentially fanatical but somewhat more armchair-expert individuals out there. I first understood the "Moon" people as being the actual KSP devs called in by NASA managemenr to persuade them to stagger their project away from NASA's (although I suppose it would have been more obviously that if it was a conference table setting, being faced over, rather than some typical office desk), with similar thoughts about the above cash payments comment (though I ''suppose'' it could be using petty-cash for site licensing or similar?)... Either way, I'm sure the "moonlighting" pun could be added into the explanation, if someone else would like to! ;) [[Special:Contributions/162.158.158.183|162.158.158.183]] 18:25, 18 September 2019 (UTC)
:I'm pretty sure the joke is that NASA engineers would be too busy playing KSP2 to assist the lunch, similarly to how MMORPG players take vacation when a new expansion comes out. That seems more in line with them taking sick days and NASA executives having to bribe the videogame company to make it stop, as opposed to suing their own engineers because they call in sick to take a second job.--[[Special:Contributions/188.114.103.101|188.114.103.101]] 18:54, 18 September 2019 (UTC)
::I agree. I don't think the same people working for NASA are also working for the private Mexico-based company Squad that created KSP and are creating KSP 2. The real joke is that the NASA engineers are likely to want to play with the new KSP, to the extent they would take vacation and sick days off to play it. If an engineer were truely working for two companies, they would still be required to come to work and couldn't just decide to stop working -- aside from abusing paid time off policies. [[User:N0lqu|-boB]] ([[User talk:N0lqu|talk]]) 19:37, 18 September 2019 (UTC)
:::Correction: Its Star Theory that's making KSP2, while SQUAD is currently maintaining KSP1. While SQUAD and Star Theory have been discussing over the development, Star Theory is independent from SQUAD. However, both are affiliated with Private Division. {{unsigned ip|141.101.99.65}}
::::Fixed it. Playing with KSP2 is now the primary, with programming it being an alternate explanation. [[User:N0lqu|-boB]] ([[User talk:N0lqu|talk]]) 20:11, 18 September 2019 (UTC)

No Linux support for KSP 2... My disappointment is measurable. [[User:Linker|Linker]] ([[User talk:Linker|talk]]) 20:30, 18 September 2019 (UTC)

I think "give you the moon" may be a reference to the movie [[wikipedia:It's_a_Wonderful_Life|It's a Wonderful Life]]. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 20:38, 18 September 2019 (UTC)
:I agree on this point. I would like to point out, upon rereading, that it says "a moon" not "the moon" - likely a reference to the fact that Mars has two moons. [[Special:Contributions/172.69.70.137|172.69.70.137]]
::Disagree it is for sure the naming. Randall has an asteroid {{w|4942 Munroe}} named after him... So he knows what that means, and also used it in [[1276: Angular Size]]. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 11:37, 19 September 2019 (UTC)

I felt the standing Cueball more apologetic or confused and thus part of the KSP team. Probably partly because all the others have hair and talk. [[Special:Contributions/162.158.154.145|162.158.154.145]] 23:53, 18 September 2019 (UTC)
:I don't think so, but I can see your point at to how you could think this. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 11:36, 19 September 2019 (UTC)

So we’re getting a YouTube play through of KSP2 from Randall, right lol? {{unsigned ip|162.158.187.79}}

"... (Ksp for short) is a space flight simulation video game with a Keplerian orbital physics engine, allowing for semi-realistic orbital maneuvers" FTFY [[Special:Contributions/162.158.154.241|162.158.154.241]] 15:53, 19 September 2019 (UTC)

Talk:2198: Throw

2019-09-05T08:09:47Z

162.158.154.241: Reference to Mjolnir

I created this page as it seem DgbrtBOT fails because it is interactive. So far it still won't shown on the front page or with a button to it from the previous comic or the "newest" comic button. Maybe it just takes some time? It is now in the [[List_of_all_comics]] but still no luck getting it to work... --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 07:58, 3 September 2019 (UTC)
:Maybe it is because it was published on a tuesday? --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 08:16, 3 September 2019 (UTC)
::No it is not unusual that a comic does not come out on MWF. For instance the Sunday comic recently. Here is the list of Tuesday comics: [[:Category:Tuesday_comics]]--[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 13:29, 3 September 2019 (UTC)
:Also it doesn't display my comment below the explanation. Something is very broken here...--[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 08:25, 3 September 2019 (UTC)
:It appears now. [[User:PkmnQ|PkmnQ]] ([[User talk:PkmnQ|talk]]) 08:53, 3 September 2019 (UTC)
How did he get an estimate for Carly Rae Jepson, anyway? [[Special:Contributions/162.158.255.34|162.158.255.34]] 09:52, 3 September 2019 (UTC)
:https://www.youtube.com/watch?v=AgwAywJlo1M [[Special:Contributions/172.68.142.221|172.68.142.221]] 09:55, 3 September 2019 (UTC)
::Alternatively he could have worked together with her, as with Serena Williams. I will look it up in the afternoon, when I have my preordered book :) --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 10:22, 3 September 2019 (UTC)

By the transitive property of Worthiness, if Capt America can throw Thor's Hammer, surely George Washington is Worthy!{{unsigned ip|172.69.68.141}}

I got this data from the code:
{| class="wikitable"
! id
! name
! canThrow
! canBeThrown
! length
! diameter
! mass
! dragC
! throwPower
|-
| microwave
| A microwave oven
| false
| true
| 0.406
| 0.406
| 10.591
| 0.8
|
|-
| basketball
| a basketball
| false
| true
| 0.243
| 0.243
| 0.624
| 0.3
|
|-
| blender
| a blender
| false
| true
| 0.203
| 0.203
| 5.216
| 0.8
|
|-
| gold_bar
| a gold bar
| false
| true
| 0.0535
| 0.0535
| 12.4
| 0.8
|
|-
| cake
| a wedding cake
| false
| true
| 0.51
| 0.51
| 13
| 0.8
|
|-
| pingpong
| a ping pong ball
| false
| true
| 0.04
| 0.04
| 0.003
| 0.5
|
|-
| quarterback
| an NFL quarterback
| true
| false
| 1.905
| 0.584
| 102.058
| 0.6
| 20
|-
| acorn
| an acorn
| false
| true
| 0.0191
| 0.0191
| 0.0045
| 0.3
|
|-
| hammer
| thor's hammer
| false
| true
| 0.5
| 0.15
| 2000
| 0.4
|
|-
| javelin
| a javelin
| false
| true
| 1.8
| 0.0254
| 0.8
| 0.1
|
|-
| george
| George Washington
| true
| true
| 1.829
| 0.562
| 90.718
| 0.6
| 15
|-
| pikachu
| Pikachu
| true
| true
| 0.4
| 0.3
| 5.9874
| 0.4
| 10
|-
| car
| A car
| false
| true
| 4.5
| 2.134
| 1179.34
| 0.25
|
|-
| silver_spin
| a silver dollar (spinning)
| false
| true
| 0.04
| 0.011
| 0.027
| 0.5
|
|-
| silver_tumble
| a silver dollar (tumbling)
| false
| true
| 0.04
| 0.04
| 0.027
| 0.66
|
|-
| carly
| Carly Rae Jepsen
| true
| false
| 1.575
| 0.46
| 49.895
| 0.6
| 10
|-
| thor
| thor, god of thunder
| true
| false
| 1.91
| 0.59
| 91
| 0.6
| 10000
|-
| chris hemsworth
| chris hemsworth
| true
| false
| 1.91
| 0.59
| 91
| 0.6
| 10
|-
| squirrel
| A squirrel
| true
| true
| 0.203
| 0.096
| 0.454
| 0.6
| 10
|}
(Sorry if this table messes the talk page.)[[Special:Contributions/162.158.78.136|162.158.78.136]] 13:51, 3 September 2019 (UTC)
:Nah its great. Not sure how to use it in the explanation yet, but guess it will go in there somehow later.--[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 14:28, 3 September 2019 (UTC)

:{| class="wikitable"
! id
! name
! canThrow
! canBeThrown
! length
! diameter
! mass
! dragC
! throwPower
|-
| you
|
|
|
|
| (mass^(1/3))/8
|
| 0.6
| 5/10/15/20
|}
:Sebastian --[[Special:Contributions/172.68.110.64|172.68.110.64]] 09:17, 4 September 2019 (UTC)

The comic looks different on my screen, not displaying multiple possible selections next to each other, but all below each other. Quite dynamic... --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 14:26, 3 September 2019 (UTC)
:If I zoom out I can make it shown only one item each line, but if I zoom in two is maximum. But it should go in the explanation when we get there.--[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 14:28, 3 September 2019 (UTC)

The suggestion to litteraly throw a party in the air could be a reference to The Hitchhiker's Guide To The Galaxy in which there is a flying building with a party in it, and there's even Thor partying in it when the protagonists are coming there. --Roger 15:12, 3 September 2019 (UTC)

Any reason why George Washington has 50% more throw power than Christ Hemsworth? Some reference? ~TK

Interesting, there appears to be additional units of measurement in the source code that were not used in the comic: "wiffles" and "light-nanoseconds" [[Special:Contributions/108.162.241.52|108.162.241.52]] 16:52, 3 September 2019 (UTC)
:I'm going to try to add those to the table; I know where nano-light seconds are, but could you give an example length that's converted to wiffles? --[[User:Account|Account]] ([[User talk:Account|talk]]) 16:41, 4 September 2019 (UTC)
::Pulled unit data from the code:
::{| class="wikitable"
! id
! plural name
! conversion
|-
|meter
|meters
|meters:1
|-
|foot
|feet
|meters:.3048
|-
|furlong
|furlongs
|meters:201.168
|-
|attoparsec
|attoparsecs
|meters:.03086
|-
|smoot
|smoots
|meters:1.7
|-
|wiffle
|wiffles
|meters:.0089
|-
|football_field
|football fields
|meters:91.44
|-
|rack_unit
|rack units
|meters:.04445
|-
|horse
|horses
|meters:2.4
|-
|manhattan_block
|manhattan blocks
|meters:80
|-
|light_nanosecond
|light-nanoseconds
|meters:.03
|-
|kilogram
|kilograms
|kg:1
|-
|pound
|pounds
|kg:.453592
|}
::N.B. Conversion for "wiffles" is off by a factor of ten (i.e. should be .089 rather than .0089). While wiffles should be the next unit above rack-units and below feet, the unit conversion typo prevents it from being accessible by any thrower-object combination, as far as I can tell. [[User:OneHunted|OneHunted]] ([[User talk:OneHunted|talk]]) 02:57, 5 September 2019 (UTC)

Does it seem... excessive to anyone else that the NFL quarterback can throw a silver dollar almost two football fields?[[Special:Contributions/172.68.142.161|172.68.142.161]] 17:08, 3 September 2019 (UTC)

The explanation for Manhattan block conversion appears to be wrong. They mention that their calculation for how large one block is was made with 4 numbers ignoring George Washington as an outlier. However there are 6 total examples of Manhattan block to use and George Washington's is not an outlier. I calculated the mean with all of the data to be 79.9142 meters.--[[User:Szeth|Szeth]] ([[User talk:Szeth|talk]]) 17:12, 3 September 2019 (UTC)

We need a table with a brief description of each thrower. [[User:DKMell|DKMell]] ([[User talk:DKMell|talk]]) 17:14, 3 September 2019 (UTC)

How do we know how old George Washington was when he throws a squirrel? Speaking of age, this format kind of reminds me of the Magnus comic: https://www.explainxkcd.com/wiki/index.php/1628:_Magnus [[Special:Contributions/108.162.241.52|108.162.241.52]] 17:41, 3 September 2019 (UTC)

I think we need to add something about the myth that George Washington threw a silver dollar across the Potomac River [[Special:Contributions/108.162.241.40|108.162.241.40]] 19:42, 3 September 2019 (UTC)
: I agree it adds to the appreciation of the humor and have added that myth to the explanation. I have also added the fact that football quarterbacks are specialists at throwing the ball. [[User:Rtanenbaum|Rtanenbaum]] ([[User talk:Rtanenbaum|talk]]) 13:55, 4 September 2019 (UTC)

Pretty sure that the ping-pong ball distances are severely overestimated due to air resistance slowing them very rapidly. Someone with lab facilities might want to check... --[[User:Marcus Rowland|Marcus Rowland]] ([[User talk:Marcus Rowland|talk]]) 19:49, 3 September 2019 (UTC)
:Sorry, never mind, I think I saw a very early version of the actual page that had the distances much greater - seems reasonable now. --[[User:Marcus Rowland|Marcus Rowland]] ([[User talk:Marcus Rowland|talk]]) 19:53, 3 September 2019 (UTC)
The buttons look to be failing simply because [[Template:LATESTCOMIC]] hasn't been updated with the lastest comic number - the page is protected so needs someone with higher powers than I. [[User:Dresken|Dresken]] ([[User talk:Dresken|talk]]) 19:59, 3 September 2019 (UTC)
'Worthiness' was only a thing in the comics. In the myths Thor had a belt of strength and a couple other things. --[[Special:Contributions/172.69.33.125|172.69.33.125]] 21:35, 3 September 2019 (UTC)

Unless I am missing something there is a unit conversion error for pound and kilogram. For instance if you enter 1.83m and 90.7kg for "YOU" the throw distance by Thor is 137m. However, if you enter the equivalent weight of 200lb you get a throw distance of 183m.[[Special:Contributions/172.68.206.28|172.68.206.28]] 23:20, 3 September 2019 (UTC)

: That is correct! The mass gets converted twice from pounds to kg. The intermediate mass (after one conversion, i.e. the correct mass) is used for deducing the diameter - so the same results cannot be easily obtained. Clearly a bug! Sebastian --[[Special:Contributions/172.68.110.82|172.68.110.82]] 13:47, 4 September 2019 (UTC)

"An American football field (where Randall comes from) is 100 yards or 91.44 m long" Please rewrite. I don't think (and I humbly reserve the right to be wrong) that Randall did not come from a football field. [[User:OtterlyAmazin|OtterlyAmazin]] ([[User talk:OtterlyAmazin|talk]]) 23:24, 3 September 2019 (UTC)
: I attempted a rewrite per your request - hopefully I have addressed the issue without making things worse. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 01:37, 4 September 2019 (UTC)
::I've substituted another explanation - American Football (the game with the field implied to be measured here) is ''not'' only played in North America, and Canadioan Football fields, in North America, have different measurements. No doubt someone else will replace my edit in turn.[[Special:Contributions/108.162.210.238|108.162.210.238]] 03:02, 4 September 2019 (UTC)

Should images of the throwers and objects be included? As the comic image is not interactive as the full comic, one cannot see what Randall's version of e.g. Thor or Chris H. looks like, without of visiting the actual comic and using it. Similar things have been done with other interactive comics (IIRC). --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 06:13, 4 September 2019 (UTC)
: I tried to do just that. However, apparently, only special users are allowed to upload files: "Upload error - You do not have permission to create new pages." An uploaded image file seems to count as a "page" for MediaWiki. I prepared a 7zip file with all of this comic's thrower/item images from xkcd, already properly renamed. It's [https://ufile.io/qq1klu37 available for download here]. In case some mighty editor comes along and would want to upload the images and insert them on this page, please feel free to do so. --[[User:Passerby|Passerby]] ([[User talk:Passerby|talk]]) 20:20, 4 September 2019 (UTC)

Could somebody figure out the equation he's using from the book and post it in the explanation? --[[User:Account|Account]] ([[User talk:Account|talk]]) 14:57, 4 September 2019 (UTC)

Instead of Carly Rae Jepsen, he should have used Kelsey Plum who throws t-shirts like a cannon! [https://www.youtube.com/watch?v=NeO2BSHj36I] [[User:Rtanenbaum|Rtanenbaum]] ([[User talk:Rtanenbaum|talk]]) 15:16, 4 September 2019 (UTC)

Used Formulas:

g = 9.805;

A = (3 * thrower_length * thrower_throwPower * thrower_mass / (object_mass + thrower_mass / 1000))^(1 / 3);

B = sqrt(2 * object_mass * g / (PI * (object_diameter / 2)^2 * 1.2041 * object_dragC));

Result = A^2 * sqrt(2) / (g * sqrt(A^4 / B^4 * 0.8 + A^2 / B^2 * 3 + 2));

Sebastian --[[Special:Contributions/172.68.110.64|172.68.110.64]] 15:39, 4 September 2019 (UTC), slightly corrected on --[[Special:Contributions/172.68.110.64|172.68.110.64]] 21:37, 4 September 2019 (UTC)

: 1,2041 is in units of kg/m³ and is the density of air at sea level; both A and B are in units of speed m/s; throwPower is in m²/s³, or equivalently in m/s * N/kg. Sebastian --[[Special:Contributions/172.68.110.82|172.68.110.82]] 21:22, 4 September 2019 (UTC)

I posted this yesterday but it didn't "take." The alternative distance-units used are entirely a function of the distance thrown in meters:
light-nanoseconds (1.00-1.06m), atto-parsecs (1.07-2.69m), rack units (2.70-6.67m), feet (6.68-16m), smoots (16-36m), horses (36-75m), manhattan blocks (75-131m), football fields (132-201m), furlongs (201m+). It's not true that only Thor uses furlongs; a sufficiently large and athletic custom thrower can throw a javelin 206 furlongs. To get light-nanometers, trying having a minimally-athletic "You" 0.2m tall and 129kg throw a gold brick.
-[[User:Jojo|Jojo]] ([[User talk:Jojo|talk]]) 18:44, 4 September 2019 (UTC)

Er, I meant "to get light-nanoseconds." (It's my first post. Obviously I had to make a mistake.) --[[User:Jojo|Jojo]] ([[User talk:Jojo|talk]]) 18:48, 4 September 2019 (UTC)

Should the hotlinking/embedding image at https://imgs.xkcd.com/comics/throw.png be referencd somehow? [[User:Kyuuhachi|Kyuuhachi]] ([[User talk:Kyuuhachi|talk]]) 20:17, 4 September 2019 (UTC)

Re: Mjolnir, an enchanted hammer in Marvel comics? Does this reference take priority over the Norse myths: https://en.wikipedia.org/wiki/Mj%C3%B6lnir

1237: QR Code

2019-06-02T14:47:22Z

162.158.154.241: /* Explanation */

{{comic
| number = 1237
| date = July 12, 2013
| title = QR Code
| image = qr code.png
| titletext = Remember, the installer is watching the camera for the checksum it generated, so you have to scan it using your own phone.
}}

==Explanation==
{{W|QR code}}s (quick response codes) are a type of 2D barcode that can be scanned using any of several apps on a smartphone. This comic illustrates installation of a new application that requires the smartphone to scan a QR code on its own screen. There is no conceivable purpose for such a step, so it would be completely silly. Even with two mirrors or a front-facing camera and mirror, most smartphones would be unable to simultaneously display the camera feed for the QR scanner and the QR code itself. The only way to do it would be to take a picture of the QR code with a digital camera and then scan the screen of the camera. The "12 seconds remaining" part indicates that there is a time limit for this, and thus a ''quick response'' is necessary.

If scanned, the QR code in the comic reads <tt>http://xkcd.com/1237/scan/</tt>, a link to a nearly identical image, but the line above the QR code reads, "To continue reading," and the caption reads, "How to trap a webcomic reader in an infinite loop". The QR code is identical to the previous one. So, if scanned again, it would simply return the scanner to the same image in an "infinite loop".

==Transcript==
:[A smartphone. On the display, the following text:]
:"To continue installing, scan this code. 12 seconds remaining"
:[A particularly recursive QR code is displayed on the screen.]
:How to freak out a mobile app user.

{{comic discussion}}

1237: QR Code

2019-06-02T14:46:51Z

162.158.154.241:

{{comic
| number = 1237
| date = July 12, 2013
| title = QR Code
| image = qr code.png
| titletext = Remember, the installer is watching the camera for the checksum it generated, so you have to scan it using your own phone.
}}

==Explanation==
{{W|QR code}}s (quick response codes) are a type of 2D barcode that can be scanned using any of several apps on a smartphone. This comic illustrates installation of a new application that requires the smartphone to scan a QR code on its own screen. There is no conceivable purpose for such a step, so it would be completely silly. Even with two mirrors or a front-facing camera and mirror, most smartphones would be unable to simultaneously display the camera feed for the QR scanner and the QR code itself. The only way to do it would be to take a picture of the QR code with a digital camera and then scan the screen of the camera. The "12 seconds remaining" part indicates that there is a time limit for this, and this a ''quick response'' is necessary.

If scanned, the QR code in the comic reads <tt>http://xkcd.com/1237/scan/</tt>, a link to a nearly identical image, but the line above the QR code reads, "To continue reading," and the caption reads, "How to trap a webcomic reader in an infinite loop". The QR code is identical to the previous one. So, if scanned again, it would simply return the scanner to the same image in an "infinite loop".

==Transcript==
:[A smartphone. On the display, the following text:]
:"To continue installing, scan this code. 12 seconds remaining"
:[A particularly recursive QR code is displayed on the screen.]
:How to freak out a mobile app user.

{{comic discussion}}

Talk:2153: Effects of High Altitude

2019-05-24T09:34:02Z

162.158.154.241:

I don’t even know where to begin. [[User:Netherin5|“That Guy from the Netherlands”]] ([[User talk:Netherin5|talk]]) 18:00, 22 May 2019 (UTC)
:Is that because in the netherlands you do not have any experience with the effects of high altitude? --[[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 08:10, 23 May 2019 (UTC)

Can anyone verify if the baseballs and golf balls actually fly further? I'd assume it's due to lower air density and therefore resistance, not weaker gravity as someone else had written. [[User:Cgrimes85|Cgrimes85]] ([[User talk:Cgrimes85|talk]]) 18:13, 22 May 2019 (UTC)
:Both parts (air resistance and gravity) play a role here. [[Special:Contributions/172.68.51.106|172.68.51.106]] 18:17, 22 May 2019 (UTC)
::At 1 mile altitude the acceleration due to gravity is only about 0.05% less than at sea level, so I don't think it's important relative to the lower air resistance. [[User:Cgrimes85|Cgrimes85]] ([[User talk:Cgrimes85|talk]]) 18:53, 22 May 2019 (UTC)
:::The difference in gravity due to being 1 mile farther away from the center of the earth is negligible and due to having more mass(aka mountains) under them Denver actually has a slightly higher Local Gravitational Acceleration at 9.81112m/s^2 than say Los Angeles at 9.80636m/s^2. [https://www.wolframalpha.com/widgets/gallery/view.jsp?id=e856809e0d522d3153e2e7e8ec263bf2 wolfram alpha source] Decreased air resistance is the reason for flying further. [[User:Stickfigurefan|Stickfigurefan]] ([[User talk:Stickfigurefan|talk]]) 19:21, 22 May 2019 (UTC)
:Note however that the spin-induced lift would be lower in the thinner air which would somewhat counteract the reduced gravity and air drag.[[Special:Contributions/108.162.241.4|108.162.241.4]] 12:40, 23 May 2019 (UTC)
:This is a fairly commonly recognized phenomenon. Many golf publications reference this. e.g. [https://www.titleist.com/teamtitleist/b/tourblog/posts/the-effect-of-altitude-golf-ball-aerodynamics Titleist post][[User:OhFFS|OhFFS]] ([[User talk:OhFFS|talk]]) 21:20, 22 May 2019 (UTC)
:This is also commonly recognized in baseball. For example, [this paper[http://baseball.physics.illinois.edu/Denver.html] argues that after the spin-induced lift reduction ball will still fly 5% farther in Denver than in Boston due to altitude.[[Special:Contributions/108.162.216.172|108.162.216.172]] 14:08, 23 May 2019 (UTC)
:Considering the negligible effect of gravity on balls distances (and boiling temperatures and sunburns for that matter), should we not just remove any references to gravity from the main explanation?[[Special:Contributions/162.158.154.241|162.158.154.241]] 09:34, 24 May 2019 (UTC)

I'd say the last frame is a reference to 5 o'clock time for drinks. On urban dictionary there's a reference to 4:20 being the time to 'smoke the reefer' [[User:Palmpje|Palmpje]] ([[User talk:Palmpje|talk]]) 18:17, 22 May 2019 (UTC)
:It's definitely about weed, not liquor. See [https://en.wikipedia.org/wiki/420_(cannabis_culture) Wikipedia article on 420]. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 18:36, 22 May 2019 (UTC)
:The frame says it's about marijuana. How is this one in question? [[User:OhFFS|OhFFS]] ([[User talk:OhFFS|talk]]) 21:21, 22 May 2019 (UTC)

Although the comic relates to nuclear war neither the original German text nor the English reworked text (it's definitely not a direct translation) refer to nuclear war. Both refer to unidentified objects however so I've adapted the explanation to that end. [[User:Palmpje|Palmpje]] ([[User talk:Palmpje|talk]]) 19:18, 22 May 2019 (UTC)
:There appears to be some debate around the UFOs. In my opinion the original German text should prevail (I'm Dutch, not German). The original lyrics state "hielt man für UFO's aus dem All"
which means "thought they were UFOs from space". The English lyrics are not that definite. Anyway - a large 99 (or is it 94 at altitude?) year war broke out just because of some hyper-tense generals. [[User:Palmpje|Palmpje]] ([[User talk:Palmpje|talk]]) 19:45, 22 May 2019 (UTC)
::The comic refers to "red" balloons, which which are only present in the English version. The original German text doesn't mention the color of the "Luftballons", so it's not so obvious that this version should prevail.[[Special:Contributions/141.101.107.240|141.101.107.240]] 13:47, 23 May 2019 (UTC)

The "420" mile marker on Interstate 70 in Colorado was replaced by a "419.99" marker because it kept getting stolen. [http://loweringthebar.net/2014/01/colorado-removes-420-mile-marker.html]. [[User:Probably not Douglas Hofstadter|Probably not Douglas Hofstadter]] ([[User talk:Probably not Douglas Hofstadter|talk]]) 14:46, 23 May 2019 (UTC)

Talk:2152: Westerns

2019-05-20T10:14:44Z

162.158.154.241:

How many times longer than the {{w|Regency era}} (a decade) have {{w|Regency romance}} novels existed? A fair bit more than three, I'd guess! (Perhaps 8.4, if we credit 1935 as the start and the Regency period as ten years) [[User:JohnHawkinson|JohnHawkinson]] ([[User talk:JohnHawkinson|talk]]) 05:41, 20 May 2019 (UTC)
:A similar question has been answered about WW2 by Randall: https://what-if.xkcd.com/100/ [[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 08:53, 20 May 2019 (UTC)
::Trivia about What-if #100: in another example of xkcd-inspired achievements, there now exists a short movie about the Anglo-Zanzibar war (http://www.imdb.com/keyword/anglo-zanzibar-war/). Plot keywords: stupid world record, cell camera, anglo zanzibar war.[[Special:Contributions/162.158.154.241|162.158.154.241]] 10:14, 20 May 2019 (UTC)

2150: XKeyboarCD

2019-05-19T12:28:24Z

162.158.154.241: /* Explanation */

{{comic
| number = 2150
| date = May 15, 2019
| title = XKeyboarCD
| image = xkeyboarcd.png
| titletext = The key caps use LCD displays for all the vowels, so they can automatically adjust over the years to reflect ongoing vowel shifts while allowing you to keep typing phonetically.
}}

==Explanation==
{{incomplete|Created by a LEOPARD USING AN XKEYBOARCD. Seems to be finished, could someone check it again before deleting this tag? Do NOT delete this tag too soon.}}

In the same vein as the [[:Category:xkcd Phones|xkcd Phone series]], the XKeyboarCD seems to be an overly inventive and borderline ludicrous keyboard intended for some unknown audience. It has an assortment of features (some fairly normal, some more exotic) which give it a..."diverse skill set".

This is the second time that the "xkcd" has been used around a middle word, which uses some of the xkcd letters to form this word. The first was [[1506: xkcloud]] - XKC lou D, to spell ClouD with the C and D from XKCD, in that comic the letters where all lowercase. In this comic the Keyboard, has an X before the word and a C before the D with the xkcd letters capitalized.

*'''54 Configurable Rubik's Keys'''
The smaller cubes on a {{w|Rubik's cube}} resemble computer keys, so this feature makes fun of that by adding a spinnable Rubik's cube above the keyboard. The implication is that the keys would be 'configured' by twisting the sides of the cube until the desired configuration is reached, although parity means that not all configurations could be reached by conventional means. The bottom center position can't contain a key because it's the mounting position, so there can be a maximum of 53 keys. Additionally, the top key can't be moved around so the maximum amount of configurable keys is 52. (The four remaining centers can be moved by rotating the entire cube.) The rearmost and bottom-facing keys would obviously be hard to see/reach.

*'''Hardcoded Plastic Keys for the 5 Most Useful Emoji'''
This feature parodies the feature of some laptop-keyboards where it is possible to dynamically assign emojis to a small touchscreen area. There is a disaccord between hard-coded, useful and emoji, especially with the keys having such large size and being positioned in a central position of the keyboard. Which emojis would be "the most useful" is highly subjective. For example in the comic it shows the quite popular laughing with tears emoji, along with the octopus emoji and others. Notably, the "aerial tramway" was once the least-used emoji, and remains very rarely used.
{| class="wikitable"
|-
! Emoji
! Name
|-
| 😰
| [https://emojipedia.org/face-with-open-mouth-and-cold-sweat/ Anxious Face With Sweat]
|-
| 😂
| [https://emojipedia.org/face-with-tears-of-joy/ Face With Tears of Joy]
|-
| 🐙
| [https://emojipedia.org/octopus/ Octopus]
|-
| 🏇
| [https://emojipedia.org/horse-racing/ Horse Racing]
|-
| 🚡
| [https://emojipedia.org/aerial-tramway/ Aerial Tramway]
|}

*'''Serif Lock'''
{{w|Serifs}} are small lines on the ends of certain characters in fonts such as Times New Roman and Georgia. It is dependent on the font, not on the key pressed; "A" is represented by the same code regardless of its font. Since a given font almost always either has or doesn't have serifs, this key seems challenging to implement. This key could be implemented, however, by simply changing between a pair of fonts when it is pressed. What's more, the button is placed roughly where left shift is on most keyboards, liable to cause frustration.

*'''Unlimited Key Travel'''
On a keyboard, key travel refers to the distance the key moves between its unpressed and pressed states. In reality, laptop keys only move a few millimeters before bottoming out, and conventional keyboards up to about a centimeter. An increased key travel may make typing more comfortable. However, the usefulness of having unlimited key travel is unclear, and the question of how this would be physically possible in the keyboard depicted remains unanswered. At least it is the greatest possible value, trumping any other keyboard.

*'''Diagonal Spacebar'''
Instead of a wide key at the bottom that typists can hit easily with either thumb, we now have a tall, narrow key that requires being pressed with the right pinkie. This would not be a good change since most peoples' pinkies are their weakest finger. Some ergonomic keyboards have a slightly curved spacebar or a separated spacebar for each thumb.

*'''Arrow Key (Rotate to Adjust Direction)'''
Most computers have four {{w|arrow keys}}: up, left, right, and down. However, the XKeyboarCD just has one that can be rotated. This has the added bonus of allowing the arrow keys to point more than four different directions. While innovative, its utility is questionable given trackpoint devices which provide more intuitive joystick-like control. It also comes at the cost of compatibility with certain programs, such as older video games. It would also be awkward to operate as going from horizontally left to horizontally right, for example, would require the user to rotate the key first and then press it which wastes precious time when playing a video game. There is also the problem of allowing unlimited rotation, requiring the combination of a keyswitch and angle-selection mechanism (perhaps the keycap mounted on a long square rotatable rod, keying through dual opposing potentiometers and onto a conventional key switch). This would be mechanically complex which adds to the cost of the keyboard.

*'''15 Puzzle-Style Numberpad'''
A {{w|15 puzzle}} is a square containing fifteen smaller squares and one blank spot, which allows the squares to be moved around. The squares are shuffled and then reassembled as a game or pastime, and are usually labelled 1-15 (as is the case here) or, when assembled properly, create a picture. A {{w|Numeric keypad|numberpad}} in this style would be frustrating to use for typing numbers, as they could shift (or be shifted) around, but could provide a fun feature to use as a game. Alternatively the keys could be rearranged as with the Rubik`s keys. How this would be used to generate numeric input is unclear, but the presence of 16 positions suggests {{w|hexadecimal}} input is possible. Keyboard keypads do have around 17 keys, but only 0-9 usually have numbers whereas the XKCD keypad has numbers 10-15 in the middle of the numberpad probably also surrounded by the more conventional arithmetic operators, enter, and decimal point.

*'''Ergonomic Design'''
The cylindrical portion of the keyboard is advertised as being an ergonomic design. Most ergonomic keyboards are both curved into a convex shape and split in the middle, with the blocks of keys on either side rotated around the vertical axis. This is done to follow natural arm and finger movements more closely, that is, avoid forcing the user to rotate their arms and hands to match the flat and rectangular key arrangement of a non-ergonomic keyboard. Some ergonomic keyboards come in unconventional form factors, such as vertical keyboards, to allow the user's hands to rest in more neutral positions or to change positions throughout the day, but the cylinder shape presented here is a ''concave'' shape which requires the user to lift and twist his arms to reach certain keys (or roll the cylinder from side to side), which would be an even more strenuous motion than typing on a standard keyboard. The slogan of the keyboard - "for power users and their powerful fingers" fits this difficulty -, but makes no sense as a feature.

*'''Title Text'''
The title text references sound changes in languages. Every language (and indeed, every dialect) routinely undergoes changes in its sounds and phonemes, in a mostly regular and systematic, but not totally predictibale way (otherways the dialects would sound the same and also the century, when a shift occurs, and the rate of change are not predictable). While not only vowels are affected, in languages with many vowels such as English, they're particularly likely to shift around and/or merge. While having dynamic keycaps that change can actually come in handy, the feature of only having vowels change in response to sound shifts is a bit less so. One normally enters the spelling and not the pronounciation of words (except with some Asian input systems). The spelling and pronounciation do not change at the same time.

First, while changes in how we pronounce words are always ongoing, the way we write words down tends to stay relatively static, and thahs wiy wuhd faynd thaet werds biykahm ihncaampriyhehnsihbuhl duw tuw now laanger biyihng spehlld aes they wer bihfaor. Second, English only uses five glyphs (aeiou) and a variety of methods to represent four times as many vowel sounds, so the software would need to have a way to handling that (in some dialects "bird" and "turn" for example, have the same vowel but are represented by "ir" and "ur", as it also can be by the "er" in the bird ''called'' the "{{w|tern}}"). Third, vowel shifts are not ubiquitous: the {{w|Caught-cot merger}}, for example, is a phenomenon happening across some parts (but not all) of the US and UK. Therefore, while some people would say "caught" and "cot have the same vowel it should be spelled the same by the keyboard, but others would say they're two different vowels and should not be spelled identically. Fourth, sound shifts tend to occur over a relatively long period of time (in terms of human lifetimes), so a user would probably find the keycaps only change once or twice. All in all, this is not a very useful feature.

An alternative explanation is that the keys actually map to the {{w|International Phonetic Alphabet}} and converts what you type into English words (and the vowel changes). The IPA is an alphabet used in linguistics and language teaching, designed to represent every phoneme present in languages of the world unambiguously, with optional modifiers to indicate more subtle nuances in pronunciation, intonation and speech pathology. This alphabet consists of 107 letters and 56 modifiers (with some letters shared with the Latin and Greek alphabets), which would explain the large number of keys. In that case, the feature remains questionable since it only handles vowel shifts and not consonants, and anybody who'd use an IPA-keyboard would probably need to type out the phonology of other languages and appreciate not having to find a key has moved because English has undergone a vowel shift.

==Transcript==
:[Headings above a drawing of a very special keyboard:]
:Introducing the
:<big>XKeyboarCD</big>
:A keyboard for powerful users and their powerful fingers®

:[The keyboard has many more keys than a usual Keyboard. Usual keyboards for stationary computers typically have a few of the rows with 21 keys, and then some with fewer. This Keyboard has 28 keys on the top row. The other rows have special keys that make it difficult to compare, but there is basically also room for 28 in the bottom row, except one spot where there is one key in a space for 2x2 keys. Begining from the bottom and coutning keys there are 27. Skipping those that take up space in two or more rows, when going to the next row from the bottom there are 23, then 24, then 18, then 27 and finally 28 keys in the top row, for a total of 147 keys (vs 105 on a regular keyboard). Then there are 54 extra keys above the keyboard to the left (27 shown) and 156 in 6 rows of 26 to the right for a total of 357 keys 330 shown. All six rows have keys all the way over with no empty space in between, as there are on regular keyboards. Also there are no space between the top row (with F1 button etc) and those below. At each side of the keyboard the keys do no align at the edges, which is normally the case. The keyboard has several special features, most of which are labeled. The only special features that is not labeled is a small square with 2x2 keys that are elevated a bit above all other keys. It is in the region above the normal position of the four arrows. All eight other special features have an arrow pointing to them from their labels. Here below is a description of the labeled items as well as a transcript of their labels. They are listed in the order of their labels first above and then below the keyboard going from left to right.]

:[Five keys close to the QWERTY keys positions have colorful emoji on them. They each take up the space of 2x2 normal keys, although it is not clear if all the "normal" keys have the same size:]
:Hardcoded plastic keys for the 5 most useful emoji
:😰 😂 🐙 🏇 🚡

:[A cube with 3x3 keys on each side hangs above the keyboard to the left supported by a small rod. Three sides are fully visible, 27 keys:]
:54 configurable Rubik's keys

:[Just right of the middle above the main keyboard is a cylinder with keys inside in 6 rows of 26 keys (126 in all). It either decreases in diameter into it making it look almost like a tunnel, or is drawn as if it almost disappear in the far distance, being much deeper than it should be.]
:Ergonomic design

:[In the region where the normal numberpad would be there are 15 numbers from 1 to 15 in a 4x4 grid leaving space for an empty key hole. There is a row of keys both above and below this grid. The numbers do not come in order from 1 to 15, but rather in a jumble. Also the empty hole is not a full key spot. Instead it is in the second row of numbers, with a bit more space to the left than to the right of the middle of the three keys.]
:
:{| class="wikitable"
|+15 puzzle-style numberpad
|-
|1
|8
|4
|12
|-
|7
|
|11
|3
|-
|15
|6
|10
|9
|-
|2
|5
|13
|14
|}

:[To the left in the second row (below the Caps Lock position) the outer key is twice as wide as the other normal keys.]
:Serif Lock

:[An arrow points to the eight key in the bottom row, but is probably just referring to all the keys in general:]
:Unlimited key travel

:[There is a segment of the keyboard that seems to be empty of keys, but still white like the rest of the keys, not black as where keys are actually missing. It is where on a regular keyboard, the normal keys are separated from the special function keys. But it turns out it is indeed a long key going vertically:]
:Diagonal spacebar

:[Where the four arrow keys are on a regular keyboard there is a 2x2 key segment that only has one key in the middle with black background around it. It has an arrow head on it pointing right. That is if the key had not been turned about 45 degree counter clockwise, so the arrow points up to the right.]
:Arrow key (rotate to adjust direction)

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Emoji]]

2147: Appendicitis

2019-05-09T16:41:55Z

162.158.154.241: /* Explanation */ added saline solution explanation

{{comic
| number = 2147
| date = May 8, 2019
| title = Appendicitis
| image = appendicitis.png
| titletext = Fortunately, after a brief skirmish, I seem to have gained the upper hand in the battle against my internal organs, at least until they learn to read and find out the mean stuff I've said about them.
}}

==Explanation==
{{incomplete|Created by a ROGUE ORGAN. Does anyone know where Randall's surgery was announced? If so, please add the link to the explanation. Do NOT delete this tag too soon.}}

[[Cueball]] is visiting [[Ponytail#Doctor_Ponytail|Doctor Ponytail]], this time to diagnose some medical condition. From her description, ''zapped you with energy beams'', it sounds like they just took an {{w|Projectional radiography|x-ray image}}, maybe in the form of a {{w|CT scan}}, and Ponytail is following up on the results. It appears that he may have {{w|appendicitis}}, the title of the comic, which could be treated through {{w|antibiotics}}, or through an {{w|appendectomy}} surgery.

As is typical for Doctor Ponytail, she characterizes the diagnosis in a strange and not-entirely-helpful way, in this case likening Cueball's inflamed appendix to a social uprising or rebellion. In some ways, this is not a bad metaphor - Cueball is an organism, and as such, functions best when all of his organic parts are working correctly in unison. People often express the similar sentiment of being "betrayed by their own body" to describe a biological function that isn't working right. However, Doctor Ponytail insists on talking ''only'' in metaphor, preventing Cueball from getting any useful medical detail about his condition.

Antibiotic treatment is described as using "chemical / biological weapons", while the appendectomy is described as "victory through the sword". She further describes more extreme "battle tactics", like crushing all other rebellions in his body. Lastly, she mentions "salting his abdomen" to prevent other rebellions. This is a reference to the {{w|salting the earth}} tactic in battle, which was a ritual to symbolize a curse on a conquered city and would have theoretically have hindered future crop production, thus preventing that city from being rebuilt. It is likely that the medical usage would be the application of saline solution, salt in water, which is used for cleaning wounds.

A possible alternate explanation of panel three and four could involve cancer. Panel three could be construed as exploratory surgery. Panel four could be referencing cancer-preventative drugs.

After all this explanation, Cueball begins to question Ponytail's methods, and requests to see a different doctor to get a {{w|Second_opinion#Medicine|second opinion}}.

The title text continues the battle metaphor, saying that Cueball is defeating his illness, at least until they can read his words against them.

Two days before posting this comic Randall had a case of Appendicitis{{Citation needed}}, but is now recovering after surgery.

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Cueball is seated on an medical examination table while Ponytail stands dressed in a doctor's coat holding a file on a clipboard in her left hand.]
:Ponytail: Well, we zapped you with energy beams, and it looks like one of your stupid organs is a traitor.
:Cueball: ...which one?
:Ponytail: I dunno, appendix? Gallbladder? One of the little ones that sucks.
:Cueball: What should I do?

:[Closeup on Ponytail. She holds her left hand in a clenched fist.]
:Ponytail: You could quash the revolt with the ruthless deployment of chemical and biological weapons.
:Cueball (off-screen): ...antibiotics?
:Ponytail: But certain victory comes only through ''the sword''.
:Cueball (off-screen): Surgery.

:[Closeup on Ponytail with her fists raised.]
:Ponytail: While we're inside, we'll look around-if we see any signs of insurrection elsewhere, we will not hesitate to act. There can be no armistice. Your parts must fall in line or be crushed.
:Cueball (off-screen): Um.

:[Zoom out again to the entire scene. Ponytail points her left hand up.]
:Ponytail: When the battle is won, we will salt your abdomen so no new organs can ever sprout up to trouble you again.
:Cueball: Maybe I should get a second opinion.
:Ponytail: Only if you care what a ''weaker'' doctor would say.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Ponytail]]

Talk:2140: Reinvent the Wheel

2019-04-23T09:39:02Z

162.158.154.241: it works, so what could be the problem?

I took a screenshot of google image search at 2:24 PM ET on 4/22/2019, and a bicycle wheel is indeed the first result. I'm trying to figure out how to get my image into the wiki ;p [[Special:Contributions/162.158.78.82|162.158.78.82]] 18:25, 22 April 2019 (UTC)
: (same user) Man! I found an old account I made and logged in with it to upload a file, but it says I need special permission to do so! [[User:Baffo32|Baffo32]] ([[User talk:Baffo32|talk]]) 18:33, 22 April 2019 (UTC)
: If somebody with permission could upload this, it would be great: https://ipfs.io/ipfs/Qmf1a9NFFAcgWRUe45Ueg4FggXTUAd9BHMgEqWp23izchU [[User:Baffo32|Baffo32]] ([[User talk:Baffo32|talk]]) 18:43, 22 April 2019 (UTC)

: I get this (in the UK, using Google UK, and same result in a fresh Incognito session): https://www.makerlab-electronics.com/product/65mm-rubber-wheel-blue/ It looks like a decent wheel, albeit probably a bit small for most uses [[Special:Contributions/141.101.99.11|141.101.99.11]] 22:41, 22 April 2019 (UTC)

I looked for a cheese wheel by searching wheel but couldn't find any. there was, however, a roulette wheel [[Special:Contributions/172.68.47.72|172.68.47.72]] 20:41, 22 April 2019 (UTC)

Looks like beret guy is working for an automotive startup, possibly one of the many software companies that are developing AI for self-driving cars? It is true that tires are made by outside suppliers (not by the auto companies) so in terms of software development tires could be called "external dependencies". However, tires are far from a semi-random selection as intimated here. A large amount of time and effort is spent developing special tires for each vehicle model to give the best possible compromise between many conflicting requirements such as: dry/wet/snow traction, noise, ride, wear, high speed durability (for high performance cars) and so on, the complete list has many more items.

If Randall is looking for new tires for his vehicle, I offer my standard recommendation: If you were fairly happy with the tires that came with the car, try and replace them with the closest possible equivalent to take advantage of the original development effort. This is not always possible, and of course if you are using the vehicle for a special purpose (mostly drive on dirt roads, use your car in weekend autocross competition, etc.), you may do better with something different.[[Special:Contributions/162.158.75.58|162.158.75.58]] 18:36, 22 April 2019 (UTC)

This comic could also be talking about coding, where reinventing the wheel is writing your own code from scratch, as there is other code which works perfectly well. This makes particular sense as the "external dependencies" could be in terms of code as well
[[User:Gollum|Gollum]] ([[User talk:Gollum|talk]]) 18:45, 22 April 2019 (UTC)

I think the point is that their company is having to reinvent their cars to fit each dependency wheel, rather than develop a wheel that will fit their preexisting car. For cars, wheels are for the most part interchangeable, but external dependencies in software are very much not so. [[Special:Contributions/108.162.229.100|108.162.229.100]]

I suspect this is a comment on JavaScript (JS) coding for the web, specifically the NPM node.js package manager. I'm not a front-end Web developer, but apparently lots of web pages use NPM to pull down dependencies, bits of code to accomplish some task, rather than write it new (thus, avoid 'reinventing the wheel'). The problem is there's poor control over what those dependencies do and how they might get modified on you unexpectedly. See the [https://en.wikipedia.org/wiki/Npm_(software)#Notable_breakages Wikipedia article] on NPM for some history of bad breakages that have occurred.
: I second this comment as being the key to the explanation. Especially when your external dependencies are also hosted on sites that you don't control; any functionality that you depend on can be replaced at any time, analogous to swapping out a sedan's tire for a bicycle tire. [[Special:Contributions/108.162.215.202|108.162.215.202]] 20:03, 22 April 2019 (UTC)
: thirded. googling a solution to your coding problem and then implementing it (as a third-party library or as code directly) is very much as described in this comic. yay, randall! --[[Special:Contributions/162.158.154.241|162.158.154.241]] 09:39, 23 April 2019 (UTC)

The point of the comic is likely that the term "Reinvent the Wheel" is not typically used in a literal sense to refer to actual wheels, as it is in this comic. Instead, it usually refers to exerting effort on something that adds no value over re-using something that already exists, whether it's a product's design or something intangible like an idea or study. We could probably provide a link to the Wikipedia article on the topic to help readers who are unfamiliar with the phrase. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 19:38, 22 April 2019 (UTC)

I don't have a problem with the explanation mentioning that the comic might be making some statement about software developers carelessly using code off the Internet, but I'm not sure we can say with such certainty that this IS the point of the comic, as it currently states. I certainly don't get any indication that it's specifically about JavaScript. I think Randall just thought the phrase "Reinvent the Wheel" would be funny if he had a character using it literally, and anything deeper than that might just be our own personal issues. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 22:32, 22 April 2019 (UTC)

There is nothing in the comic that's specifically about JavaScript, although the issues with NPM are a good example of what can happen more generally in other environments. But the terms "external dependencies" and "reduced overhead", plus looking for wheels on Google and the title text mentioning reinventing the vehicle to fit the wheel, to me are a clear sign that this is an analogy for software development. [[Special:Contributions/172.69.226.195|172.69.226.195]] 02:28, 23 April 2019 (UTC)

"That one time a wheel of cheese got dangerously close to the front page" - Is this a reference to that time SpaceX launched a wheel of cheese into space as a demo payload? [[Special:Contributions/172.68.255.104|172.68.255.104]] 08:01, 23 April 2019 (UTC)

2106: Sharing Options

2019-02-02T13:49:05Z

162.158.154.241:

{{comic
| number = 2106
| date = February 1, 2019
| title = Sharing Options
| image = sharing_options.png
| titletext = How about posts that are public, but every time a company accesses a bunch of them, the API makes their CEO's account click 'like' on one of them at random so you get a notification.
}}

==Explanation==
{{incomplete|Created by 300 or a billion BOTs. Please mention here why this explanation isn't complete. Do NOT delete this tag too soon.}}
This comic is a satire of social media's presence in our lives and its vulnerabilities. [[Cueball]] is flying in an atmosphere that resembles a VR cyberspace, and he is talking to a screen that may be a smartphone with an advanced virtual assistant installed. [[Ponytail]] and other characters also fly in the background, so this cyberspace may be the social network's cyberspace where everyone interacts. The clouds represent the cloud server where the data of the social network is stored. The advanced virtual assistant seems to have a virtual face and have very advanced AI, which can even be arrogant by assuming that it already knew the information about the "option in between".

Many social media sites allow users to control who is able to see data (posts, pictures etc.) that they share online, ranging from immediate friends to all other users (public). The settings for controlling the sharing of data are not always obvious to the user and several high profile social media sites have sparked controversy by having default settings that allow user data to be widely shared.

As most social media sites are free to use, the business model for these companies involves a mixture of selling advertising space on their website and selling data on its users to other companies, who may be interested in using it for marketing purposes. Targeted advertising takes data on users past behavior and things that they have liked and uses this to predict what adverts they may be interested in. Targeted adverts are more valuable to advertisers as they avoid paying to show adverts to individuals who are unlikely to be interested in their products, but can lead to users feeling that they are being spied on. Whilst the terms and conditions for social media websites will include details of how data will be used, the length of these documents and legal terminology may deter some users from reading them, meaning that they may be unaware that their data is being exploited in this way. Government legislation has so far been slow to catch up with changing online trends, however the European Union have recently introduced {{w|General Data Protection Regulation|General Data Protection Regulations (GDPR)}} which aims to regulate how user data can be shared. GDPR was featured in comic [[1998: GDPR]].

Randall, who might have never heard of the Facebook option to share with "friends of friends" as well, is making a point that there ought to be some option between sharing posts only with your friends and making them completely public. The title text shows that he would specifically like to know when corporations read his posts.

Randall might be interested in [https://www.scuttlebutt.nz/ scuttlebutt] or [https://secushare.org/ secushare].

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Cueball floating in midair is communicating with a small floating screen that resembles a smartphone. Other people and clouds visible floating by in background.]
:Screen: Welcome to social media! When you put stuff here, you have two options: (1) You can make it available to a small set of 300 or so approved friends.
:Screen: Or (2) you can share permanent copies of it all with billions of people, including internet scammers, random predatory companies, and hostile governments.

:Cueball: Why would anyone pick option two?
:Screen: Two is the default.
:Cueball: Yikes.

:Cueball: So those are the only two options? There's nothing in in between?
:Screen: I don't understand. Like what?

:Cueball: I mean...there are numbers between 300 and a billion.
:Screen: Huh? Name one.
:Screen: ''Pretty'' sure I would have heard of those.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Social networking]]

2104: Biff Tannen

2019-01-29T13:57:27Z

162.158.154.241: Tom Wilson's comments seem important to add here.

{{comic
| number = 2104
| date = January 28, 2019
| title = Biff Tannen
| image = biff_tannen.png
| titletext = I can't help myself; now I want to read a bunch of thinkpieces from newspapers in Biff's 1985 arguing over whether the growth of the region into a corporate dystopia was inevitable.
}}

==Explanation==

This comic is based on ''{{w|Back to the Future II}}''. In this movie, the character Biff Tannen steals the time machine, which is the main plot device, and uses it to go back in time from 2015 to 1955. He then gives Marty McFly’s sports almanac, containing the outcomes of 50 years (1950–2000) worth of sporting events, to his younger self. His younger self uses this sports almanac to make millions by successfully betting on {{w|horse races}}. He then forms a company, and calls it [https://backtothefuture.fandom.com/wiki/BiffCo BiffCo]. While in the movie the protagonists reverse this, by stealing the almanac back, Cueball imagines the universe where BiffCo exists as continuing to exist in parallel. This is consistent with the {{w|multiverse}} theory.

Cueball mentions that this universe would not have any ''counterfactuals'' to work with. This is often short in epistemology for {{w|counterfactual conditionals}}, that is, conditional statements about what ''would'' be true if something ''were'' true that we know for a fact is not true. For instance, Randall’s “[[what if?]]” series is based on counterfactuals, for it explores hypotheticals—conditionals which are contrary to fact. The first post in that series, about what would happen if a baseball were hit at 90% the speed of light, is a counterfactual, because we know for a fact that a baseball has never been hit at such a speed{{Citation needed}}. In the case of the universe where BiffCo exists, they would not have any information on the ''counterfactuals'', that is, the facts about what would happen if Biff did not have this almanac.

The movie is set in the fictional town of Hill Valley, California. When the protagonists return to 1985, they find that Biff has turned the town’s “Courthouse Square” into a 27-story casino, and generally taken over Hill Valley. Cueball interprets this as “the decline of the city, and general social decay”.

''[https://en.wikipedia.org/wiki/Hillbilly_Elegy Hillbilly Elegy: A Memoir of a Family and Culture in Crisis]'' is a book, published in June 2016, that gives an account of growing up in a poor Rust Belt town, and offers a broader, probing look at the struggles of America’s white working class. This comic is a play on the title of this book, which has been described as explaining the “social, regional, and class” issues in white working-class America. The white American working class was a key factor in the election of U.S. President Donald Trump, and many critics have interpreted the book as an explanation of his election, which was deemed improbable by many analysts before it happened. Netflix [https://deadline.com/2019/01/netflix-hillbilly-elegy-ron-howard-movie-deal-40m-1202541118/ purchased the rights] to an upcoming film adaptation of the book three days before this comic, prompting another wave of criticism of the book's theories.

Cueball is proposing a similarly-titled book, set in the ''Back to the Future II'' universe where BiffCo exists, that would describe the supposed factors leading to the rise of Biff Tannen in Hill Valley. In that universe, while the rise of Biff—and the subsequent decay of the city—is the result of his using a future sports almanac to cheat at sports betting, the rest of the population would have to guess at the structural societal issues that might have caused Biff’s otherwise inexplicable success. Thus, Cueball compares such blind guessing with the analysis contained in ''Hillbilly Elegy''.

This makes White Hat Guy angry, because it’s such a painfully long setup for a really stupid pun. There is also a decent chance that the book White Hat Guy is currently reading is ''Hillbilly Elegy'', which would make the joke more insulting to him, as it compares the book to useless theorizing about an event which was really caused by time traveling. After seeing similar symptoms in our society, perhaps he would consider that we are living in such a world predetermined to negative effects. It would probably frustrate him that being optimistic for the future and hoping for a changing society would be an effort in vain, when the universe is similarly tampered with by time-travellers. Alternatively, he is enjoying the book and is angry at the insult to it.

[[Randall]] is known to have [[1756: I'm With Her|supported Hillary Clinton]], the opposing candidate, in the 2016 election, having made a comic just to promote her, and particularly [[1779: 2017|sad comics]] following Trump's election. Therefore, he may have made this comic as an insult to a book which supposedly explains the election of the candidate he opposed, by comparing it to useless (and wrong) theorizing. It may also be intended as an insult to Trump himself, by comparing the dystopian universe where Biff rose to power (albeit not as President) to the actual universe where Trump rose to power.

Alternatively, the comic may be an allusion to alleged Russian tampering of the 2016 U.S. elections: Randall is proposing that it is futile to attribute Donald Trump's rise to power to any set of structural, societal issues that may have acted indirectly while ignoring the hidden, speculated, but far more direct cause of foul play, just as it would be futile to analyze Biff Tannen's rise to power by similar means, ignoring the impact of foul play via time travel and a sports almanac.

The title text continues this comparison by mentioning thinkpieces from newspapers that would appear in the ''Back to the Future II'' universe where BiffCo exists. Various thinkpieces did appear in real life newspapers in an attempt to explain Trump’s rise to power after his election, and asking whether it was inevitable.

As ''{{w|Back to the Future II}}''’s important October 2015 setting date approached, commentators began noting the similarities between the older version of the character Biff Tannen and then presidential candidate Donald Trump. When the comparison was brought to the attention of the film’s writer, Bob Gale, in an interview, he [https://www.thedailybeast.com/back-to-the-future-writer-biff-tannen-is-based-on-donald-trump# claimed] that elements of Tannen’s personality were actually based on Trump, who was already well known in the late 1980s for his work in real estate and tabloid controversies. Thus, there is a real connection between Biff Tannen and Donald Trump. This supports the comparison between the two made by Randall. That being said, actor Tom Wilson has [https://www.youtube.com/watch?v=c4lYCaFx3Og denied] that his performance of the role was in any way based on Trump.

==Transcript==

:[Cueball talks while walking up behind White Hat, who is reading in an armchair.]
:Cueball: You know, in the universe where Biff Tannen took Marty McFly’s sports almanac back in time, the people wouldn’t have any counterfactuals to work with.
:Cueball: Their world would be ''the'' world.

:[White Hat turns his head to look at Cueball as he keeps talking.]
:Cueball: They would have spent decades debating which structural problems enabled the rise of BiffCo, the decline of the city, and general social decay.
:Cueball: Everyone would find reasons it confirmed their pet theory.

:Cueball: I'm going to write a book set in that universe. I'll call it ''Hill Valley Elegy''.
:[White Hat turns his head back to his book in disgust.]
:White Hat: ... I ''hate'' you.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring White Hat]]
[[Category:Fiction]]
[[Category:Time travel]]

1275: int(pi)

2018-09-28T08:32:33Z

162.158.154.241: /* Explanation */ better link

{{comic
| number = 1275
| date = October 9, 2013
| title = int(pi)
| image = int pi.png
| titletext = If replacing all the '3's doesn't fix your code, remove the 4s, too, with 'ceiling(pi) / floor(pi) * pi * r^floor(pi)'. Mmm, floor pie.
}}

==Explanation==
This comic purports to provide a tip to programmers, that the number "{{w|3 (number)|3}}" is cursed and shouldn't be used. There is no explanation given as to why the number 3 is cursed, and it could well have been chosen arbitrarily. The title text hints that the consequence for using the cursed number is non-functioning code, a pain for any programmer. The absurdity of the number 3 somehow being cursed is part of the humor.

To assist the programmer, the comic gives an example of how to avoid the use of the number 3, by using a slightly convoluted method of using <code>int(pi)</code>, which means the {{w|integer}} part of {{w|pi}}, without the {{w|fractional part}}. Pi, an {{w|irrational number}}, has a value starting <code>3.14159...</code>, making <code>int(pi)</code> equal to 3. This is demonstrated in a formula to calculate the {{w|Sphere#Enclosed volume|volume of a sphere}}, normally (4/3)*pi*(r^3), but converted for avoidance of the number 3 to (4/int(pi))*pi*(r^int(pi)).

For a number of reasons it is a good programming practice to use {{w|Variable (computer science)|variables}} and {{w|Constant (programming)|constants}} where a value is used in multiple places, however this is not typically used in the case of natural numbers. There are unusual situations where this type of programming is a valid method, however typically for more specific circumstances, and not a certain number being seen as cursed.

In the title text, Randall takes the joke a step further, suggesting the usage of {{w|floor and ceiling functions}}: <code>ceiling(pi)</code> would be pi rounded ''up'' to the next integer, which is {{w|4 (number)|4}}; and <code>floor(pi)</code> is pi rounded ''down'' to the next integer, which is 3. (Note that <code>int(n)</code> and <code>floor(n)</code> have the same value when <code>n</code> is greater than or equal to zero. For values less than zero, <code>int(n)</code> is equal to <code>ceiling(n)</code>.)

The joke here plays on the fact that basic rules of programming are confusing and novice programmers are often told to simply not do certain things without any explanation (see [[292: goto]]). This includes, in particular, a general proscription against "{{w|Magic number (programming)#Unnamed numerical constants|magic numbers}}" in the code. Replacing all significant magic numbers with named constants makes programs easier to read, understand and maintain. Randall takes this to an extreme by suggesting that certain numbers could be inherently problematic, but the general idea is perfectly believable.

[https://youtube.com/watch?v=MYgchYm0syg ''Mmm... Floor pie.''] is a reference to The Simpsons.

See also {{w|Cargo cult programming}}.

==Transcript==
:volume(r) = (4/int(pi))*pi*r^int(pi)
:Programming Tip: The number "3" is cursed. Avoid it.

{{comic discussion}}
[[Category:Programming]]
[[Category:Geometry]]

Talk:975: Occulting Telescope

2018-09-24T19:13:41Z

162.158.154.241: directing all of a stars energy to one planet is a bad Idea

A personal lesson I've learned long ago that I would like to share with Mr. XKCD and others: Don't worry about things you don't have direct control over, try to help people that do have control better understand the challenge they are facing and you will feel great with every accomplishment (similar to remembering to bring that reusable bag of yours to the store). If you don't know anyone with control, but feel you have a lesson to teach about the universe around us, put it in fiction form for future generations to learn from, and we will reward you with riches for it. - e-inspired [[Special:Contributions/98.211.199.84|98.211.199.84]] 15:51, 27 February 2013 (UTC)

Wouldn't the disk covering the star reflect sunlight so the observer would end up with an EVEN BIGGER SPOT in the sky where the star used to be? {{unsigned ip|162.158.92.106}}
:I assume you're talking about light from our Sun and not light from the observed star. Of course the disc would be made of dark non-reflecting material, the opposite of a mirror. But even if it would be a mirror it reflects only in one direction. Put a (reflecting) coin in your hand far away as possible and aim to every point around you, even when you intent to see the reflection of the Sun by having it just behind you it's not easy to see it. And turn only a tick to the left you see nothing. BTW: Please sign your comments. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 19:17, 20 September 2018 (UTC)

I don't think that sending all the energy back of a star to ONE planet would be advisable... mostly due to the scale of energy likely destroying said planet(or if not making it uninhabitable(unless they are horribly inefficient)) or (using our system(the solar system(our original solar system(the one with the planet Earth)))) all of the planets in our solar system, although it could be used to increase the amount of energy received by those planets [[Special:Contributions/162.158.154.241|162.158.154.241]] 19:13, 24 September 2018 (UTC) 20:14 , 24 September 2018

2048: Curve-Fitting

2018-09-22T01:04:14Z

162.158.154.241:

{{comic
| number = 2048
| date = September 19, 2018
| title = Curve-Fitting
| image = curve_fitting.png
| titletext = Cauchy-Lorentz: "Something alarmingly mathematical is happening, and you should probably pause to Google my name and check what field I originally worked in."
}}

==Explanation==
{{incomplete|Please edit the explanation below and only mention here why it isn't complete. Do NOT delete this tag too soon.}}

An illustration of several plots of the same data with {{w|Curve fitting|curves fitted}} to the points, paired with conclusions that you might draw about the person who made them. This data, when plotted on an X/Y graph, looks somewhat random and there is a desire or need to determine some kind of pattern. With some kinds of data the pattern can be visually obvious, and perhaps a straight or diagonal line, represented by a simple mathematical formula, hits or comes very near hitting all the points. In other cases where it's not as intuitively obvious, one begins to look for more sophisticated mathematical formulas that appear to fit the data, in order to be able to extrapolate or interpolate other data that wasn't in the initial sampling.

When modeling such a problem statistically, it is common to search for trends, and fitted curves can help reveal these trends. Much of the work of a data scientist or statistician is knowing which fitting method to use for the data in question. Here we see various hypothetical scientists or statisticians each applying their own interpretations, and the comic mocks each of them for their various personal biases or other assorted excuses. In general, the researcher will specify the form of an equation for the line to be drawn, and an algorithm will produce the actual line.

Nonetheless scientists work much more seriously on the reliability of their assumptions by giving a value for the {{w|Standard deviation|standard deviation}} represented by the Greek letter sigma σ or the Latin letter s as a measure to quantify the amount of variation of the data points against the presented ''best fit''. If the σ-value isn't good enough an interpretation based on a specific fit wouldn't be accepted by the science community.

Since [[Randall]] gives no hint about the nature of the used data set - same in each graph - any fitting presented doesn't make any sense. The graphs could represent a star map, the votes for the latest elected presidents, or your recent invoices on power consumption. This comic just exaggerates various methods on interpreting data, but without the knowledge of the matter in the background nothing makes any sense.

===Linear===
[[File:Anscombe's quartet 3.svg|thumb|200px|Different data sets result in the same regression.]]
<math>f(x) = mx + b</math>

{{w|Linear regression}} is the most basic form of regression; it tries to find the straight line that best approximates the data. As it's the simplest, most widely taught form of regression, and in general derivable function are locally well approximated by a straight line, it's usually the first and most trivial attempt of fit.

The picture to the right shows how totally different data sets can result into the same line. It's obvious that some more basics about the nature of the data must be used to understand if this simple line really does make sense.

The comment below the graph ''"Hey, I did a regression."'' refers to the fact that this is just the easiest way of fitting data into a curve.

===Quadratic===
<math>f(x) = ax^2 + bx + c</math>

{{w|Polynomial regression|Quadratic fit}} (i.e. fitting a parabola through the data) is the lowest grade polynomial that can be used to fit data through a curved line; if the data exhibits clearly "curved" behavior (or if the experimenter feels that its growth should be more than linear), a parabola is often the first, easiest, stab at fitting the data.

The comment below the graph ''"I wanted a curved line, so I made one with math."'' refers to the fact that quadratic correlations like this are mathematically valid (and probably the simplest kind of curve in math) but rarely occur in real life.

===Logarithmic===
[[File:Logarithm_plots.png|thumb|200px|Common logarithm functions.]]
<math>f(x) = a\log_b(x) + c</math>

A {{w|Logarithm|logarithmic}} curve growths slower on higher values, but still grows without bound to infinity rather than approaching a horizontal {{w|asymptote}}. The small ''b'' in the formula represents the base which is in most cases 2, ''{{w|e (mathematical constant)|e}}'', or 10. If the data presumably does approach a horizontal asymptote then this fit isn't an effective method to explain the nature of the data.

The comment below the graph ''"Look, it's tapering off!"'' builds up the impression that the data diminishes while under this fit it's still growing to infinity, only much slower than a linear regression does.

===Exponential===
[[File:Exponential.svg|thumb|200px|Exponential growth (green) compared to other functions.]]
<math>f(x) = a\cdot b^x + c</math>

An {{w|Exponential growth|exponential curve}}, on the contrary, is typical of a phenomenon whose growth gets rapidly faster and faster - a common case is a process that generates stuff that contributes to the process itself, think bacteria growth or compound interest.

The logarithmic and exponential interpretations could very easily be fudged or engineered by a researcher with an agenda (such as by taking a misleading subset or even outright lying about the regression), which the comic mocks by juxtaposing them side-by-side on the same set of data.

The comment below the graph ''"Look, it's growing uncontrollably!"'' gives an other frivolous statement suggesting something like chaos. Also this even faster growth is well defined and has no asymptote at both axes.

===LOESS===
A {{w|Local regression|LOESS fit}} doesn't use a single formula to fit all the data, but approximates data points locally using different polynomials for each "zone" (weighting differently data points as they get further from it) and patching them together. As it has much more degrees of freedom compared to a single polynomial, it generally "fits better" to any data set, although it is generally impossible to derive any strong, "clean" mathematical correlation from it - it is just a nice smooth line that approximates well the data points, with a good degree of rejection from outliers.

The comment below the graph ''"I'm sophisticated, not like those bumbling polynomial people."'' emphasis this more complicated interpretation but without a simple mathematical description it's not much helpful to find academic descriptions on the underlying matter.

===Linear, No Slope===
<math>f(x) = c</math>

Apparently, the person making this line figured out pretty early on that their data analysis was turning into a scatter plot, and wanted to escape their personal stigma of scatter plots by drawing an obviously false regression line on top of it. Alternatively, they were hoping the data would be flat, and are trying to pretend that there's no real trend to the data by drawing a horizontal trend line.

The comment below the graph ''"I'm making a scatter plot but I don't want to."'' is probably done by a student who isn't happy with it's choice of field of study.

===Logistic===
[[File:Logistic-curve.svg|thumb|200px|A standard logistic function between the values ''0'' and ''1''.]]
The {{w|Logistic regression|logistic regression}} is taken when a variable can take binary results such as "0" and "1" or "old" and "young".

The curve provides a smooth, S-shaped transition curve between two flat intervals (like "0" and "1").

The comment below the graph ''"I need to connect these two lines, but my first idea didn't have enough math."'' implies the experimenter just wants to find a mathematically-respectable way to link two flat lines.

===Confidence Interval===
Not a type of curve fitting, but a method of depicting the predictive power of a curve.

Providing a confidence interval over the graph shows the uncertainty of the acquired data, thus acknowledging the uncertain results of the experiment, and showing the will not to "cheat" with "easy" regression curves.

The comment below the graph ''"Listen, science is hard. But I'm a serious person doing my best."'' is just an honest statement about this uncertainty.

===Piecewise===
Mapping different curves to different segments of the data. This is a legitimate strategy, but the different segments should be meaningful, such as if they were pulled from different populations.

This kind of fit would arise naturally in a study based on a regression discontinuity design. For instance, if students who score below a certain cutoff must take remedial classes, the line for outcomes of those below the cutoff would reasonably be separate from the one for outcomes above the cutoff; the distance between the end of the two lines could be considered the effect of the treatment, under certain assumptions. This kind of study design is used to investigate causal theories, where mere correlation in observational data is not enough to prove anything. Thus, the associated text would be appropriate; there is a theory, and data that might prove the theory is hard to find.

One notable time this is used is when a researcher studying housing economics is trying to identify housing submarkets. The assumption is that if two proposed markets are truly different, they will be better described using two different regression functions than if one were to be used.

The additional curved lines visible in the graph are the kind of confidence intervals you'd get from a simple OLS regression if the standard assumptions were valid. In the case of two separate regressions, it would be surprising if all those assumptions (that is, i.i.d. Normal residuals around an underlying perfectly-linear function) were in fact valid for each part, especially if the slopes are not equal.

A classical example in physics are the different theories to explain the black body radiation at the end of the 19th century. The {{w|Wien approximation}} was good for small wavelengths while the {{w|Rayleigh–Jeans law}} worked for the larger scales (large wavelength means low frequency and thus low energy.) But there was a gap in the middle which was filled by the {{w|Planck's law}} in 1900.

The comment below the graph ''"I have a theory, and this is the only data I could find."'' is a bit ambiguous because there are many data points ignored. Without an explanation why only a subset of the data is used this isn't a useful interpretation at all.

===Connecting lines===
This is often used to smooth gaps in measurements. A simple example is the weather temperature which is often measured in distinct intervals. When the intervals are high enough it's safe to assume that the temperature didn't change that much between them and connecting the data points by lines doesn't distort the real situation in many cases.

The comment below the graph ''"I clicked 'Smooth Lines' in {{w|Microsoft Excel|Excel}}."'' refers to the well known spreadsheet application from {{w|Microsoft Office}}. Like other spreadsheet applications it has the feature to visualize data from a table into a graph by many ways. "Smooth Lines" is a setting meant for use on a {{w|line graph}} and is purely aesthetic; as it simply joins up every point rather than finding a sensible line, it is not suitable for regression.

===Ad-Hoc Filter===
Drawing a bunch of different lines by hand, keeping in only the data points perceived as "good". Not really useful except for marketing purposes.

The comment below the graph ''"I had an idea for how to clean up the data. What do you think?"'' admits that in fact the data is whitewashed and tightly focused to a result the presenter wants to show.

===House of Cards===
Not a real method, but a common consequence of misapplication of statistical methods: a curve can be generated that fits the data extremely well, but immediately becomes absurd as soon as one glances outside the training data sample range, and your analysis comes crashing down "like a house of cards". This is a type of ''overfitting''. In other words, the model may do quite well for (approximately) {{w|Interpolation|interpolating}} between values in the sample range, but not extend at all well to {{w|Extrapolation|extrapolating}} values outside that range.

''Note:'' Exact polynomial fitting, a fit which gives the unique <math>(n-1)</math>th degree polynomial through <math>n</math> points, often display this kind of behaviour.

The comment below the graph ''"As you can see, this model smoothly fits the- wait no no don't extend it AAAAAA!!"'' refers to a curve which fits the data points relatively well within the graph's boundaries, but beyond those bounds fails to match at all.

The name is also a reference to the TV show {{w|House of Cards (U.S. TV series)|''House of Cards''}} ("WAIT NO, NO, DON'T EXTEND IT!").

===Cauchy-Lorentz (title text)===
{{w|Cauchy_distribution|Cauchy-Lorentz}} is a continuous probability distribution which does not have an expected value or a defined variance. This means that the law of large numbers does not hold and that estimating e.g. the sample mean will diverge (be all over the place) the more data points you have. Hence very troublesome (mathematically alarming).

Since so many different models can fit this data set at first glance, Randall may be making a point about how if a data set is sufficiently messy, you can read any trend you want into it, and the trend that is chosen may say more about the researcher than about the data. This is a similar sentiment to [[1725: Linear Regression]], which also pokes fun at dubious trend lines on scatterplots.

A brief Google search reveals that Augustin-Louis Cauchy originally worked as a junior engineer in a managerial position. Upon his acceptance to the Académie des Sciences in March 1816, many of his peers expressed outrage. Despite his early work in "mere" engineering, Cauchy is widely regarded as one of the founding influences in the rigorous study of calculus & accompanying proofs.

Alternately, the title-text could be implying that the person who applied the Cauchy-Lorentz curve-fitting method may not be well qualified to the task assigned.

==Transcript==
:'''Curve-Fitting Methods'''
:and the messages they send

:[In a single frame twelve scatter plots with unlabeled x- and y-axes are shown. Each plot consists of the same data-set of approximately thirty points located all over the plot but slightly more distributed around the diagonal. Every plot shows in red a different fitting method which is labeled on top in gray.]

:[The first plot shows a line starting at the left bottom above the x-axis rising towards the points to the right.]
:Linear
:"Hey, I did a regression."

:[The second plot shows a curve falling slightly down and then rising up to the right.]
:Quadratic
:"I wanted a curved line, so I made one with math."

:[At the third plot the curve starts near the left bottom and increases more and more less to the right.]
:Logarithmic
:"Look, it's tapering off!"

:[The fourth plot shows a curve starting near the left bottom and increases more and more steeper towards the right.]
:Exponential
:"Look, it's growing uncontrollably!"

:[The fifth plot uses a fitting to match many points. It starts at the left bottom, increases, then decreases, then rapidly increasing again, and finally reaching a plateau.]
:LOESS
:"I'm sophisticated, not like those bumbling polynomial people."

:[The sixth plot simply shows a line above but parallel to the x-axis.]
:Linear, no slope
:"I'm making a scatter plot but I don't want to."

:[At plot #7 starts at a plateau above the x-axis, then increases, and finally reaches a higher plateau.]
:Logistic
:"I need to connect these two lines, but my first idea didn't have enough Math."

:[Plot #8 shows two red lines embedding most points and the area between is painted as a red shadow.]
:Confidence interval
:"Listen, science is hard. But I'm a serious person doing my best."

:[Plot #9 shows two not connected lines, one at the lower left half, and one higher at the right. Both have smaller curved lines in light red above and below.]
:Piecewise
:"I have a theory, and this is the only data I could find."

:[The plot at the left bottom shows a line connecting all points from left to right, resulting in a curve going many times up and down.]
:Connecting lines
:"I clicked 'Smooth Lines' in Excel."

:[The next to last plot shows a echelon form, connecting a few real and some imaginary points.]
:Ad-Hoc filter
:"I had an idea for how to clean up the data. What do you think?"

:[The last plot shows a wave with increasing peak values. Finally the plot of the wave is continued beyond the x- and y-axis borders.]
:House of Cards
:"As you can see, this model smoothly fits the- ''wait no no don't extend it AAAAAA!!''"

==Trivia==
*This is the comic 2048, or 211. In addition to being the name of a popular app referenced in [[1344: Digits]], this is an extremely round number in binary (100,000,000,0002). [[1000: 1000 Comics]] pointed out that comic 1024 would be a round number, but there were not any comics noting 2048.

*This comic is similar to [[977: Map Projections]] which also uses a scientific method not commonly thought about by the general public to determine specific characteristics of one's personality and approach to science.

*Regressions have been the subject of several previous comics. [[1725: Linear Regression]] was about linear regressions on uncorrelated or poorly correlated data. [[1007: Sustainable]] and [[1204: Detail]] depict linear regressions on data that was actually logistic, leading to bizarre extrapolations. [[605: Extrapolating]] shows a line extrapolating from just two data points.

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Scatter plots]]
[[Category:Math]]
[[Category:Science]]

2048: Curve-Fitting

2018-09-22T00:44:44Z

162.158.154.241: /* Logarithmic */

{{comic
| number = 2048
| date = September 19, 2018
| title = Curve-Fitting
| image = curve_fitting.png
| titletext = Cauchy-Lorentz: "Something alarmingly mathematical is happening, and you should probably pause to Google my name and check what field I originally worked in."
}}

==Explanation==
{{incomplete|Please edit the explanation below and only mention here why it isn't complete. Do NOT delete this tag too soon.}}

An illustration of several plots of the same data with {{w|Curve fitting|curves fitted}} to the points, paired with conclusions that you might draw about the person who made them. This data, when plotted on an X/Y graph, looks somewhat random and there is a desire or need to determine some kind of pattern. With some kinds of data the pattern can be visually obvious, and perhaps a straight or diagonal line, represented by a simple mathematical formula, hits or comes very near hitting all the points. In other cases where it's not as intuitively obvious, one begins to look for more sophisticated mathematical formulas that appear to fit the data, in order to be able to extrapolate or interpolate other data that wasn't in the initial sampling.

When modeling such a problem statistically, it is common to search for trends, and fitted curves can help reveal these trends. Much of the work of a data scientist or statistician is knowing which fitting method to use for the data in question. Here we see various hypothetical scientists or statisticians each applying their own interpretations, and the comic mocks each of them for their various personal biases or other assorted excuses. In general, the researcher will specify the form of an equation for the line to be drawn, and an algorithm will produce the actual line.

Nonetheless scientists work much more seriously on the reliability of their assumptions by giving a value for the {{w|Standard deviation|standard deviation}} represented by the Greek letter sigma σ or the Latin letter s as a measure to quantify the amount of variation of the data points against the presented ''best fit''. If the σ-value isn't good enough an interpretation based on a specific fit wouldn't be accepted by the science community.

Since [[Randall]] gives no hint about the nature of the used data set - same in each graph - any fitting presented doesn't make any sense. The graphs could represent a star map, the votes for the latest elected presidents, or your recent invoices on power consumption. This comic just exaggerates various methods on interpreting data, but without the knowledge of the matter in the background nothing makes any sense.

===Linear===
[[File:Anscombe's quartet 3.svg|thumb|200px|Different data sets result in the same regression.]]
<math>f(x) = mx + b</math>

{{w|Linear regression}} is the most basic form of regression; it tries to find the straight line that best approximates the data. As it's the simplest, most widely taught form of regression, and in general derivable function are locally well approximated by a straight line, it's usually the first and most trivial attempt of fit.

The picture to the right shows how totally different data sets can result into the same line. It's obvious that some more basics about the nature of the data must be used to understand if this simple line really does make sense.

The comment below the graph ''"Hey, I did a regression."'' refers to the fact that this is just the easiest way of fitting data into a curve.

===Quadratic===
<math>f(x) = ax^2 + bx + c</math>

{{w|Polynomial regression|Quadratic fit}} (i.e. fitting a parabola through the data) is the lowest grade polynomial that can be used to fit data through a curved line; if the data exhibits clearly "curved" behavior (or if the experimenter feels that its growth should be more than linear), a parabola is often the first, easiest, stab at fitting the data.

The comment below the graph ''"I wanted a curved line, so I made one with math."'' refers to the fact that quadratic correlations like this are mathematically valid (and probably the simplest kind of curve in math) but rarely occur in real life.

===Logarithmic===
[[File:Logarithm_plots.png|thumb|200px|Common logarithm functions.]]
<math>f(x) = a\log_b(x) + c</math>

A {{w|Logarithm|logarithmic}} curve growths slower on higher values, but still grows without bound to infinity rather than approaching a horizontal {{w|asymptote}}. The small ''b'' in the formula represents the base which is in most cases 2, ''{{w|e (mathematical constant)|e}}'', or 10. If the data presumably does approach a horizontal asymptote then this fit isn't an effective method to explain the nature of the data.

The comment below the graph ''"Look, it's tapering off!"'' builds up the impression that the data diminishes while under this fit it's still growing to infinity, only much slower than a linear regression does.

===Exponential===
[[File:Exponential.svg|thumb|200px|Exponential growth (green) compared to other functions.]]
<math>f(x) = a\cdot b^x + c</math>

An {{w|Exponential growth|exponential curve}}, on the contrary, is typical of a phenomenon whose growth gets rapidly faster and faster - a common case is a process that generates stuff that contributes to the process itself, think bacteria growth or compound interest.

The logarithmic and exponential interpretations could very easily be fudged or engineered by a researcher with an agenda (such as by taking a misleading subset or even outright lying about the regression), which the comic mocks by juxtaposing them side-by-side on the same set of data.

The comment below the graph ''"Look, it's growing uncontrollably!"'' gives an other frivolous statement suggesting something like chaos. Also this even faster growth is well defined and has no asymptote at both axes.

===LOESS===
A {{w|Local regression|LOESS fit}} doesn't use a single formula to fit all the data, but approximates data points locally using different polynomials for each "zone" (weighting differently data points as they get further from it) and patching them together. As it has much more degrees of freedom compared to a single polynomial, it generally "fits better" to any data set, although it is generally impossible to derive any strong, "clean" mathematical correlation from it - it is just a nice smooth line that approximates well the data points, with a good degree of rejection from outliers.

The comment below the graph ''"I'm sophisticated, not like those bumbling polynomial people."'' emphasis this more complicated interpretation but without a simple mathematical description it's not much helpful to find academic descriptions on the underlying matter.

===Linear, No Slope===
<math>f(x) = c</math>

Apparently, the person making this line figured out pretty early on that their data analysis was turning into a scatter plot, and wanted to escape their personal stigma of scatter plots by drawing an obviously false regression line on top of it. Alternatively, they were hoping the data would be flat, and are trying to pretend that there's no real trend to the data by drawing a horizontal trend line.

The comment below the graph ''"I'm making a scatter plot but I don't want to."'' is probably done by a student who isn't happy with it's choice of field of study.

===Logistic===
[[File:Logistic-curve.svg|thumb|200px|A standard logistic function between the values ''0'' and ''1''.]]
The {{w|Logistic regression|logistic regression}} is taken when a variable can take binary results such as "0" and "1" or "old" and "young".

The curve provides a smooth, S-shaped transition curve between two flat intervals (like "0" and "1").

The comment below the graph ''"I need to connect these two lines, but my first idea didn't have enough Math."'' implys the experimenter just wants to find a mathematically-respectable way to link two flat lines.

===Confidence Interval===
Not a type of curve fitting, but a method of depicting the predictive power of a curve.

Providing a confidence interval over the graph shows the uncertainty of the acquired data, thus acknowledging the uncertain results of the experiment, and showing the will not to "cheat" with "easy" regression curves.

The comment below the graph ''"Listen, science is hard. But I'm a serious person doing my best."'' is just an honest statement about this uncertainty.

===Piecewise===
Mapping different curves to different segments of the data. This is a legitimate strategy, but the different segments should be meaningful, such as if they were pulled from different populations.

This kind of fit would arise naturally in a study based on a regression discontinuity design. For instance, if students who score below a certain cutoff must take remedial classes, the line for outcomes of those below the cutoff would reasonably be separate from the one for outcomes above the cutoff; the distance between the end of the two lines could be considered the effect of the treatment, under certain assumptions. This kind of study design is used to investigate causal theories, where mere correlation in observational data is not enough to prove anything. Thus, the associated text would be appropriate; there is a theory, and data that might prove the theory is hard to find.

One notable time this is used is when a researcher studying housing economics is trying to identify housing submarkets. The assumption is that if two proposed markets are truly different, they will be better described using two different regression functions than if one were to be used.

The additional curved lines visible in the graph are the kind of confidence intervals you'd get from a simple OLS regression if the standard assumptions were valid. In the case of two separate regressions, it would be surprising if all those assumptions (that is, i.i.d. Normal residuals around an underlying perfectly-linear function) were in fact valid for each part, especially if the slopes are not equal.

A classical example in physics are the different theories to explain the black body radiation at the end of the 19th century. The {{w|Wien approximation}} was good for small wavelengths while the {{w|Rayleigh–Jeans law}} worked for the larger scales (large wavelength means low frequency and thus low energy.) But there was a gap in the middle which was filled by the {{w|Planck's law}} in 1900.

The comment below the graph ''"I have a theory, and this is the only data I could find."'' is a bit ambiguous because there are many data points ignored. Without an explanation why only a subset of the data is used this isn't a useful interpretation at all.

===Connecting lines===
This is often used to smooth gaps in measurements. A simple example is the weather temperature which is often measured in distinct intervals. When the intervals are high enough it's safe to assume that the temperature didn't change that much between them and connecting the data points by lines doesn't distort the real situation in many cases.

The comment below the graph ''"I clicked 'Smooth Lines' in Excel."'' refers to the well known spreadsheet application from Microsoft. Like other spreadsheet applications it has the feature to visualize data from a table into a graph by many ways. The usage of the ''Smooth Lines'' feature here just sounds more like playing rather than investigating.

===Ad-Hoc Filter===
Drawing a bunch of different lines by hand, keeping in only the data points perceived as "good". Not really useful except for marketing purposes.

The comment below the graph ''"I had an idea for how to clean up the data. What do you think?"'' admits that in fact the data is whitewashed and tightly focused to a result the presenter wants to show.

===House of Cards===
Not a real method, but a common consequence of mis-application of statistical methods: a curve can be generated that fits the data extremely well, but immediately becomes absurd as soon as one glances outside the training data sample range, and your analysis comes crashing down "like a house of cards". This is a type of ''overfitting''. In other words, the model may do quite well for (approximately) {{w|Interpolation|interpolating}} between values in the sample range, but not extend at all well to {{w|Extrapolation|extrapolating}} values outside that range.

''Note:'' Exact polynomial fitting, a fit which gives the unique (n-1)-th degree polynomial through n points, often display this kind of behaviour.

The comment below the graph ''"As you can see, this model smoothly fits the- wait no no don't extend it AAAAAA!!"'' refers to a curve which fits the data points relatively well within the graph's boundaries, but beyond those bounds fails to match at all.

Also a potential reference to the TV show, House of Cards ("WAIT NO, NO, DON'T EXTEND IT!").

===Cauchy-Lorentz (title text)===
{{w|Cauchy_distribution|Cauchy-Lorentz}} is a continuous probability distribution which does not have an expected value or a defined variance. This means that the law of large numbers does not hold and that estimating e.g. the sample mean will diverge (be all over the place) the more data points you have. Hence very troublesome (mathematically alarming).

Since so many different models can fit this data set at first glance, Randall may be making a point about how if a data set is sufficiently messy, you can read any trend you want into it, and the trend that is chosen may say more about the researcher than about the data. This is a similar sentiment to [[1725: Linear Regression]], which also pokes fun at dubious trend lines on scatterplots.

A brief Google search reveals that Augustin-Louis Cauchy originally worked as a junior engineer in a managerial position. Upon his acceptance to the Académie des Sciences in March 1816, many of his peers expressed outrage. Despite his early work in "mere" engineering, Cauchy is widely regarded as one of the founding influences in the rigorous study of calculus & accompanying proofs.

Alternately, the title-text could be implying that the person who applied the Cauchy-Lorentz curve-fitting method may not be well qualified to the task assigned.

==Transcript==
:'''Curve-Fitting Methods'''
:and the messages they send

:[In a single frame twelve scatter plots with unlabeled x- and y-axes are shown. Each plot consists of the same data-set of approximately thirty points located all over the plot but slightly more distributed around the diagonal. Every plot shows in red a different fitting method which is labeled on top in gray.]

:[The first plot shows a line starting at the left bottom above the x-axis rising towards the points to the right.]
:Linear
:"Hey, I did a regression."

:[The second plot shows a curve falling slightly down and then rising up to the right.]
:Quadratic
:"I wanted a curved line, so I made one with math."

:[At the third plot the curve starts near the left bottom and increases more and more less to the right.]
:Logarithmic
:"Look, it's tapering off!"

:[The fourth plot shows a curve starting near the left bottom and increases more and more steeper towards the right.]
:Exponential
:"Look, it's growing uncontrollably!"

:[The fifth plot uses a fitting to match many points. It starts at the left bottom, increases, then decreases, then rapidly increasing again, and finally reaching a plateau.]
:LOESS
:"I'm sophisticated, not like those bumbling polynomial people."

:[The sixth plot simply shows a line above but parallel to the x-axis.]
:Linear, no slope
:"I'm making a scatter plot but I don't want to."

:[At plot #7 starts at a plateau above the x-axis, then increases, and finally reaches a higher plateau.]
:Logistic
:"I need to connect these two lines, but my first idea didn't have enough Math."

:[Plot #8 shows two red lines embedding most points and the area between is painted as a red shadow.]
:Confidence interval
:"Listen, science is hard. But I'm a serious person doing my best."

:[Plot #9 shows two not connected lines, one at the lower left half, and one higher at the right. Both have smaller curved lines in light red above and below.]
:Piecewise
:"I have a theory, and this is the only data I could find."

:[The plot at the left bottom shows a line connecting all points from left to right, resulting in a curve going many times up and down.]
:Connecting lines
:"I clicked 'Smooth Lines' in Excel."

:[The next to last plot shows a echelon form, connecting a few real and some imaginary points.]
:Ad-Hoc filter
:"I had an idea for how to clean up the data. What do you think?"

:[The last plot shows a wave with increasing peak values. Finally the plot of the wave is continued beyond the x- and y-axis borders.]
:House of Cards
:"As you can see, this model smoothly fits the- ''wait no no don't extend it AAAAAA!!''"

==Trivia==
*This is the comic 2048, or 211. In addition to being the name of a popular app referenced in [[1344: Digits]], this is an extremely round number in binary (100,000,000,0002). [[1000: 1000 Comics]] pointed out that comic 1024 would be a round number, but there were not any comics noting 2048.

*This comic is similar to [[977: Map Projections]] which also uses a scientific method not commonly thought about by the general public to determine specific characteristics of one's personality and approach to science.

*Regressions have been the subject of several previous comics. [[1725: Linear Regression]] was about linear regressions on uncorrelated or poorly correlated data. [[1007: Sustainable]] and [[1204: Detail]] depict linear regressions on data that was actually logistic, leading to bizarre extrapolations. [[605: Extrapolating]] shows a line extrapolating from just two data points.

{{comic discussion}}

[[Category:Comics with color]]
[[Category:Scatter plots]]
[[Category:Math]]
[[Category:Science]]

Talk:2048: Curve-Fitting

2018-09-21T10:25:35Z

162.158.154.241:

Anyways, what is the actual regression of the plot?

House of Cards: Not a real method, but a common consequence of mis-application of statistical methods: a curve can be generated that fits the data extremely well, but immediately becomes absurd as soon as one glances outside the training data sample range, and your analysis comes crashing down "like a house of cards". This is a type of _overfitting_

I'm pretty sure it refers to the TV show house of cards, the dots representing the quality of the series increasing until Netflix renewed it a bit too much {{unsigned ip|172.68.26.65}}
:This was my initial interpretation as well, since you can hypothetically extend a literal house of cards indefinitely.[[Special:Contributions/172.68.58.83|172.68.58.83]] 14:23, 20 September 2018 (UTC)

I'm a little mystified by the alt-text. Cauchy and Lorentz both seem like mathematically capable people. What am I missing? [[Special:Contributions/172.69.62.226|172.69.62.226]] 17:46, 19 September 2018 (UTC)

: Google-Fu reveals that it's a continuous probability distribution. This isn't bad per se, but it is quite visually distinctive and also can be quite...concerning if the data set isn't one where probability should be an issue. [[User:Werhdnt|Werhdnt]] ([[User talk:Werhdnt|talk]]) 18:00, 19 September 2018 (UTC)

:: This is not the issue, but the fact that the moments (such as mean and variance) of the distribution don't exist = converge. See edited explanation. So if you wanted to estimate the parameters of the distribution, taking the sample mean for example will not converge with the number of data points, and is therefore bad to attempt. It is more mathematically alarming than alarmingly mathematical. [[User:GamesAndMath|GamesAndMath]]

:: My own Google-Fu brought me to a page with this information: “The distribution is important in physics as it is the solution to the differential equation describing forced resonance, while in spectroscopy it is the description of the line shape of spectral lines.” (from here: https://www.boost.org/doc/libs/1_53_0/libs/math/doc/sf_and_dist/html/math_toolkit/dist/dist_ref/dists/cauchy_dist.html) [[User:Justinjustin7|Justinjustin7]] ([[User talk:Justinjustin7|talk]]) 18:09, 19 September 2018 (UTC)

:: True, but the "check what field I originally worked in" indicates that there might be something else going on with the meaning. [[Special:Contributions/108.162.237.238|108.162.237.238]] 12:47, 20 September 2018 (UTC)

:: I believe the point of "check what field I originally worked in" is that if somebody wasn't trained in statistics using an exotic distribution is highly suspect and suggest that either they are torturing the data to get desired results or have no idea what they are doing. [[Special:Contributions/108.162.246.11|108.162.246.11]] 05:19, 21 September 2018 (UTC)

To be honest, I'm a bit disappointed. I kinda expected a special comic with such a nice round number.. Been counting down since comic #2000... [[Special:Contributions/162.158.92.184|162.158.92.184]] 18:14, 19 September 2018 (UTC)

Different anon here, I think this is very special and if Randall makes a poster available I will be buying several to give away. Of course, part of my business is experimental data analysis and modeling...and this is a fantastic summary of common errors. {{unsigned ip|162.158.75.22}}

: Agreed. This is a very special comic, and a highly subtle title text. Direct any of your friends who do data analysis here. Sort of the next stage from the classic "correlation is not causation" comic https://xkcd.com/552/ . {{unsigned|GamesAndMath}}

'''Curve-Fitting'''

How fitting works needs to be explained. f(x)=mx+b works fine for single values, but how do we get that red line from the data set? --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 20:12, 19 September 2018 (UTC)

:Generally, you decide for some error function and then search for parameters where the sum of errors for all data points is minimal. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 22:07, 19 September 2018 (UTC)

:A typical error function is the square of the difference between the fit and the actual data point, hence "sum of squares" method. There are well-known standard formulas for finding m and b in the case of linear regression. In a linear algebra class, I saw a general method that would work for several of these (any where the fit is y = af(x)+bg(x)+...+ch(x), which includes log, exponential, quadratic, cubic, etc). I wish I could remember it. [[User:Blaisepascal|Blaisepascal]] ([[User talk:Blaisepascal|talk]]) 22:39, 19 September 2018 (UTC)
::I'm still looking for an easy example. Let's say five points (x/y) and then calculating the straight line (without and maybe with the zero-point because this is often the assumed start). Just be simple, everything else derives from that. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 21:00, 20 September 2018 (UTC)

:I wish we could include the graphics at the top of [https://en.wikipedia.org/wiki/Linear_regression#Introduction] and [https://en.wikipedia.org/wiki/Linear_regression#Interpretation] in the explanation. A lot of people are going to look at this one. [[Special:Contributions/172.68.133.168|172.68.133.168]] 17:51, 20 September 2018 (UTC)
::I've included one picture with a small explanation to the linear regression section. I think that explains it well. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 21:00, 20 September 2018 (UTC)

The data points do not have error bars, which makes the choice of fit even more ludicrous, in my opinion. If the data are that good, then I don't believe there is a correlation, it's random with some distribution. I might hang this up at work...[[User:Arppix|Arppix]] ([[User talk:Arppix|talk]]) 02:46, 20 September 2018 (UTC)
:And of course in serious science data points have error bars. This makes the fitting even more complicated and should be mentioned at the explanation. Because Randall doesn't use error bars I'm sure he refers to presentations not based on real science. Also this should be mentioned here. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 21:06, 20 September 2018 (UTC)

I hate to be negative here, as obviously some users have put a lot of effort into explaining the details behind each of the curve-fitting methods, but there's absolutely no explanation for Randall's comments on each method. While someone might learn something about the various methods by reading the explanation, they would not gain any insight on what Randall is saying about each method. In addition, the Connecting Lines explanation totally missed the fact that this isn't really even a curve-fitting method - it's just a feature of graphing software (in this case, Excel) where a smooth line is drawn through each data point from left to right rather than an example of overfitting to the data set. I think we could do better. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 02:53, 21 September 2018 (UTC)

Everyone is missing the deeper trolling here of the fisheries community at large, which shall become blindingly clear here. First, this is cartoon number 2048 (2^11), a highly interesting number. Notably, this is the year all fisheries were projected to be collapsed by Worm et al. (2006) Science 314:787-790, a prediction which gained huge attention in the media and took on a life of its own. The prediction was based on fitting a power curve to some data on collapses in catch trends. Numerous rebuttals followed, one of which pointed out that a linear fit to the data is a better fit, and predicts all fisheries collapsed in 2114 (Jaenike et al. 2007, Science 316:1285a). A list of rebuttals is found here: https://sites.google.com/a/uw.edu/most-cited-fisheries/controversies/2048-projection. Later work by the same author and critics found a different prediction and showed rebuilding of fisheries is likely (Worm et al. 2009 Science 325:578-585). Second, lest you think this is a conspiracy theory, I note that in xkcd cartoon 887, Munroe specifically notes this prediction "The future according to google search results... 2048: "Salt-water fish extinct from overfishing" https://xkcd.com/887/. Third, this kind of model-fitting exercise has long plagued fisheries researchers attempting to predict recruitment from spawning biomass.

"Ad hoc filter: Drawing a bunch of different lines by hand, keeping in only the data points perceived as "good". Also not useful. " – I guess it rather refers to data filtering, where for each point you take several points around and try to calculate some kind of mean, e.g. by rejecting most extreme points, or calculating median (see https://en.wikipedia.org/wiki/Median_filter). So it is an algorithm, not actually drawing lines by hand. Still it is tricky to draw conclusions and you can easily fool yourself with this method.

Talk:2047: Beverages

2018-09-19T16:42:21Z

162.158.154.241: Correcting formatting of a comment I previously made.

Randall Munroe needs to be less existential ... oh wait. {{unsigned ip|162.158.155.146|05:22, 17 September 2018‎ (UTC)}}

Wouldn’t it warrant being freaked out *more* if it were shaped like lungs? Now that would freak me out.
(Choking on food is but one example that even nature can not get a dual function, single endpoint API perfectly right. Luckily nature was unaware of GraphQL - or we’d have one orifice, 1 endpoint for all bodily functions. {{unsigned ip|172.69.130.70|05:36, 17 September 2018‎ (UTC)}}

:(Responding to the above unsigned) Aren’t there some animals where that is the case? Jellyfish and starfish (I think) are the examples that comes to mind, but I’m sure there are others (especially among sea life). Also wow, humanity (at least the English speaking portion) really likes naming things that aren’t fish “fish” 😂 [[User:PotatoGod|PotatoGod]] ([[User talk:PotatoGod|talk]]) 07:19, 17 September 2018 (UTC)

: But there's 'No Such Thing as a Fish' :-) https://en.wikipedia.org/wiki/No_Such_Thing_as_a_Fish --[[User:OliReading|OliReading]] ([[User talk:OliReading|talk]]) 12:31, 17 September 2018 (UTC)

: Well you can think yourself lucky that you are not designed like a flatworm which only has one opening to its digestive cavity... [[Special:Contributions/162.158.166.191|162.158.166.191]] 11:17, 17 September 2018 (UTC)

:Isn't that a cloaca?
:https://www.youtube.com/embed/_y4DbZivHCY
:[[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 13:25, 17 September 2018 (UTC)

Isn't the stream of beverages interrupted in intervals by swallowing? Sebastian --[[Special:Contributions/172.68.110.10|172.68.110.10]] 06:16, 17 September 2018 (UTC)
: The bulge in the middle of the vertical portion of the flow (oesophagus) is from the effects of peristalsis, which does not cut off the flow entirely in order to push stuff down, but leaves a little gap. That is part of the reason you can belch and barf. [[User:Nutster|Nutster]] ([[User talk:Nutster|talk]]) 12:37, 17 September 2018 (UTC)

I think what he means with "if I wait a while" the beverage at the end of digestion is then connected to the toilet, sewers and oceans... {{unsigned|Benjamin3005}}

'''Similar Imagery'''

:Radiotopia's recently released [https://www.everythingisalive.com/about "Everything is alive"] podcast's premiere episode, [https://www.everythingisalive.com/episodes/louis-can-of-cola Louis Can of Cola], is about this experience from the perspective of the beverage. The episode features a discussion of between the beverage and a the host who {spoiler alert} offers to drink it. The episode was featured by podcasting legend Roman Mars on his own Radiotopia show [https://99percentinvisible.org/ "99 Percent Invisible, podcast"] earlier this summer in July 2018. [[User:Iggynelix|Iggynelix]] ([[User talk:Iggynelix|talk]]) 12:24, 17 September 2018 (UTC)
::I've moved both to a trivia section. Doesn't explain anything. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 14:18, 17 September 2018 (UTC)
::Is The Hitchhiker's Guide to the Galaxy acknowledged? Ford Prefect warns Arthur Dent that his first space trip by hyperspace transit will be unpleasantly like being drunk, and it is. rja.carnegie@excite.com [[Special:Contributions/141.101.107.42|141.101.107.42]] 01:30, 18 September 2018 (UTC)

'''What are the two organs beneath the stomach?'''

Liver makes sense because they are involved in the digesting process; but kidneys are ruled out because they filter blood where the liquid hasn't arrived yet. Any ideas? --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 13:31, 17 September 2018 (UTC)

Looks to me like that is the stomach. The "bulge" above looks like peristalsis. [[User:Baldrickk|Baldrickk]] ([[User talk:Baldrickk|talk]]) 13:44, 17 September 2018 (UTC)

"Further two small organs with no connection to the rest are also wetted." I'm pretty sure those, "...two small organs..." are actually part of the stomach from (possibly) a previous drink of the beverage.[[Special:Contributions/162.158.79.107|162.158.79.107]] 15:24, 17 September 2018 (UTC)

: I am thinking that is just the fluid splashing around inside the one stomach, as opposed to anything making it to other organs yet. While still drinking, the fluid will be collecting in the stomach as it prepares to hit the contents with enzymes and acid to break it down prior to going to the intestines, a process that can take over an hour, depending on how complex the contents are. [[User:Nutster|Nutster]] ([[User talk:Nutster|talk]]) 10:09, 18 September 2018 (UTC)

:: I agree. While being poured, the liquid isn't filling all available space within the container, it will mainly coat the bottom (i.e. of the stomach) due to gravity or sides (i.e. esophagus) due to adhesion, and there will be splashing as well. I think those two disconnected blobs of liquid are just splashes that have become disconnected from the rest of the flowing liquid. [[User:N0lqu|-boB]] ([[User talk:N0lqu|talk]]) 18:45, 18 September 2018 (UTC)
:::I've moved this matter from the transcript to the explanation. Thanks for your suggestions. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 19:51, 18 September 2018 (UTC)

Liver isn't directly involved in digestion, which means no food passes through it, although it does absorb nutrients and is involved in bile production, which is secreted by the gallbladder in response to fats. If I had to guess, it would probably be the duodenum (first part of the small intestine). [[User:Four|Four]] ([[User talk:Four|talk]]) 23:45, 17 September 2018 (UTC)
:You're right. See my comment above. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 19:51, 18 September 2018 (UTC)

'''Invisible Man'''

The picture looks like "The Invisible Man" drinking. (Actually "Keybounce", but login is neither working nor complaining for some reason.) --[[Special:Contributions/173.245.48.177|173.245.48.177]] 20:05, 17 September 2018 (UTC)

'''Optimism/Pessimism'''

Hmm... Thinking about it logically, the glass isn't half full. Considering it's being ''emptied'', it should be considered half empty. It's probably not an overly important distinction, but I'm pedantic, and I feel Randall would probably approve...[[Special:Contributions/162.158.155.146|162.158.155.146]] 16:31, 19 September 2018 (UTC)

Talk:2046: Trum-

2018-09-14T16:49:02Z

162.158.154.241:

This is not that weird. If names were random then it would be a 1 in 26^4 = 456976 chance of a particular president matching another for the first 4, but this is a "Birthday Problem" with 44 presidents, so the probability of any two presidents sharing the first 4 characters is 1-(456976!/(456976^44 (456976 - 44)!)), which wolfram alpha is giving as 0.206%
:Yes, but we already "fulfilled our obligation" after the sixth president :) [[User:Zachweix|Zachweix]] ([[User talk:Zachweix|talk]]) 15:59, 14 September 2018 (UTC)

An approximation to the correct probability would be to do 44^2/(2 x 26^4) which would give about 0.2% chance of this happening. So fairly weird, but as the comic suggests, many things about this presidency are weirder than 0.2%.
:I love that we are now having a mathematical discussion about how weird things are in the presidency. [[User:Zachweix|Zachweix]] ([[User talk:Zachweix|talk]]) 15:58, 14 September 2018 (UTC)

Should we mention Andrew Johnson and LBJ, perhaps in a "Trivia" section? Obviously Johnson is a very common surname, but they're still unrelated presidents that share the first (and only) 7 characters of their last name. (Are there other pairs of presidents that share at least the 3 first letters of their surnames besides AJ/LBJ and HST/DJT?)
[[Special:Contributions/172.69.62.160|172.69.62.160]] 16:25, 14 September 2018 (UTC)
...And, upon reflection, I just realized Harding shares the first 3 letters with the Presidents Harrison, so that's one(?) more example.

So we discount Presidents Adams, Bush, Cleveland, Harrison and Rosevelt as being related, or being the same person.
We have the following common starts: Bu (3 names), Cl, Ha (3 names), Ta, Har, Trum and Johnson. Also A, B, C, F, G, H, J, M, P, R, T and W. [[Special:Contributions/162.158.154.241|162.158.154.241]] 16:49, 14 September 2018 (UTC)

Talk:2043: Boathouses and Houseboats

2018-09-07T17:52:07Z

162.158.154.241:

The state of California already believes that a house held by a car is a housecar:
:Vehicle Code - VEH
:DIVISION 1. WORDS AND PHRASES DEFINED [100 - 681] ( Division 1 enacted by Stats. 1959, Ch. 3. )
:362.
:A “house car” is a motor vehicle originally designed, or permanently altered, and equipped for human habitation, or to which a camper has been permanently attached. A motor vehicle to which a camper has been temporarily attached is not a house car except that, for the purposes of Division 11 (commencing with Section 21000) and Division 12 (commencing with Section 24000), a motor vehicle equipped with a camper having an axle that is designed to support a portion of the weight of the camper unit shall be considered a three-axle house car regardless of the method of attachment or manner of registration. A house car shall not be deemed to be a motortruck.[http://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=VEH&sectionNum=362.]
Bonus: "motortruck" does indeed refer to a truck that holds a motor.
[[User:Jordan Brown|Jordan Brown]] ([[User talk:Jordan Brown|talk]]) 15:57, 7 September 2018 (UTC)

Randall did just correct the comic. The first version said "this [row] held by this [column]", which would have meant, that e.g. a towtruck is a car held by a car, which is just wrong. It has just be updated to the correct "a this [column] that holds a this [row]". I do not know how to change that here. Should be mentioned in Trivia [[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 16:11, 7 September 2018 (UTC)
:Thanks for your eagle eyes. I've uploaded the new version, please be patient until the cache is expired and you can see it. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 16:48, 7 September 2018 (UTC)

'''Boat boat'''

Shouldn't a boat that holds another boat be some sort of either carrier, or at-sea repair dock?

Sort of like a mothership, or a drydock?
Or an oil rig (technically considered a ship by international law), etc?

For that matter, how about the distinction between a boat and a ship?
[[User:Keybounce|Keybounce]] ([[User talk:Keybounce|talk]]) 16:34, 7 September 2018 (UTC)
:well... with the original version it fits. a boat held by another boat is a lifeboat. But the new version it doesnt. a boat that holds another boat would be, as you say, carrier, mothership, etc. looks like randall didn't think this through to the end... [[User:Lupo|Lupo]] ([[User talk:Lupo|talk]]) 16:40, 7 September 2018 (UTC)
:Floating Drydock? [https://en.wikipedia.org/wiki/Dry_dock#Floating] {{unsigned|OldCorps}}

::Similar failing: an ''apartment'' is the small entity—the "house" that is contained by the larger house. ''Apartment building'' (or ''apartment complex'') would have been the term to be replaced. [[User:Jameslucas|jameslucas]] ([[User talk:Jameslucas|" "]] / [[Special:Contributions/Jameslucas|+]]) 17:42, 7 September 2018 (UTC)
::: Agreed. His list of words contains elements that fall into either the 'x held by y' or 'x that holds y' definition, so neither definition can work for all the words! Only way to fix is to replace some of the words as suggested ('apartment building' instead of 'apartment').[[Special:Contributions/162.158.154.241|162.158.154.241]] 17:52, 7 September 2018 (UTC)

You're entirely correct on both counts. Lifeboats are carried by other boats, and ships that can carry other ships do exist. This comic also fails to distinguish between boats and ships, and cars, trucks, and trailers.
While a Boathouse is indeed a house for boats, a boat ''trailer'' is usually a trailer and not a car- the name already follows Randell's suggested logic: it's a trailer (characterized by lacking it's own engine, steering, and driver's cabin) that holds one or more boats. In addition, both tow trucks and car carriers are large enough to be properly referred to as trucks (the smallest type of tow truck I know of is built on a pickup truck chassis) and are fully capable to towing or carrying other trucks as well as cars, making the term carcar inaccurate. Yes, I'm being pedantic, but this might be worth mentioning in explanation. [[Special:Contributions/162.158.122.60|162.158.122.60]] 16:44, 7 September 2018 (UTC)Chris Long

1908: Credit Card Rewards

2017-10-30T16:21:01Z

162.158.154.241: /* Explanation */

{{comic
| number = 1908
| date = October 27, 2017
| title = Credit Card Rewards
| image = credit_card_rewards.png
| titletext = I should make a list of all the things I could be trying to optimize, prioritized by ... well, I guess there are a few different variables I could use. I'll create a spreadsheet ...
}}

==Explanation==
{{incomplete|VERY basic explanation.}}

A credit card, at its most basic form, is a loan contract to an individual from a bank. Like all contracts, the bank will offer several different types in an attempt to appeal to a large number of individuals. Unlike traditional loans which focus on a single item (car, house, boat, etc), a credit card is an unsecured loan geared towards daily and weekly transactions. Because these transactions cover a wide variety of items, credit cards can be further tweaked towards offering benefits in certain areas. For example, gas purchases, or even gas purchases through a single retail chain, can offer higher rewards on one type of plan vs. other plans.

These benefits, typically called rewards, have several different options. "Cash back" is a reward where the individual is given money back when they make a purchase that follows certain rules spelled out in the contract. "No interest" is a reward where the individual is not charged interest on their purchases if they pay the loaned money back within a specified amount of time. "Points" are similar to the cash back program, but are typically reserved towards purchasing a single large item or plan. Points towards a vacation is a popular option. Besides these three types of rewards, the number of actual rewards to pick from are limited only by the creativity and fiscal limitations of the issuing bank.

Cueball is trying to choose the optimal credit card program (the one that will result in biggest savings with the yearly fiscal median (YFM) he has). He realizes that he has to subtract the cost of him spending time on optimizing, so he wants to optimize the time needed to do the optimizing. But in order to to that efficiently, he first has to optimize the time spent on optimizing the time.

Hairy notices a hidden assumption that Cueball will spend his time on something more productive than this (i.e. that his time has value); Cueball's obsession with optimization is lame enough to suggest that he does not actually have more worthwhile interests to pursue. Cueball responds that he can "fail to optimize so many better things!" This means that Cueball is aware both of the big flaw in his reasoning and the fact that, when he attempts to optimize things, the attempt seldom really helps his situation.

The title text further expands the idea. Cueball wants to present a list of things to optimize to Hairy. However, he still needs to optimize the priorities of that list, before optimizing the list itself. Making and working with lists like this often involves a spreadsheet, which may also be a reference to [[1906: Making Progress]].

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}

:[Cueball sits at a desk and is on his laptop. Hairy stands behind him.]
:Cueball: I'm trying to figure out which of these credit card rewards programs is best given my spending.

:[Cueball leans backwards in a frameless panel.]
:Cueball: But at some point, the cost of the time it takes me to understand the options outweighs their difference in value.

:[Close-up of Cueball's head and torso.]
:Cueball: So I need to figure out where that point is, and stop before I reach it.
:Cueball: But... when I factor in the time to calculate THAT, it changes the overall answer.

:[Cueball has his arms outstretched.]
:Hairy: I question the assumption that you'd otherwise be spending your time on something more valuable.
:Cueball: Come on, I could be failing to optimize so many better things!

{{comic discussion}}

[[Category:Comics featuring Hairy]]
[[Category:Comics featuring Cueball]]