explain xkcd - User contributions [en]

1047: Approximations

2013-10-15T23:54:07Z

Anon: /* Explanation */ remove incorrect assertion: in fact √2 is algebraic -- specifically, quadratic -- over Z(pi) or even Z(1)

{{comic
| number = 1047
| date = April 25, 2012
| title = Approximations
| image = approximations.png
| titletext = Two tips: 1) 8675309 is not just prime, it's a twin prime, and 2) if you ever find yourself raising log(anything)^e or taking the pi-th root of anything, set down the marker and back away from the whiteboard; something has gone horribly wrong.
}}

==Explanation==
{{incomplete}}
This comic lists some approximations for numbers, most of them mathematical and physical constants. All of them work astonishingly well. There are reoccurring math jokes along the lines of, “3/5 + π/(7 – π) – √2 = 0, but your calculator is probably not good enough to compute this correctly”, which are mainly used to troll geeks.

Furthermore, there are some useful approximations (which were even more useful in times before calculators) such as “pi is approximately equal to 22/7”.

[[Randall]] makes fun of both of these, using rather strange approximations (honestly: you may handle 22/7, but who can calculate in a sensible way with 99^8, let alone 30^(pi^e)?) to calculate some constants that are easy enough to handle in the decimal system, and stating such “slightly wrong” trick equations, one of which ''is'' actually correct (which may astonish only those who are not familiar with cosines).

There are a few cultural references in this comic:

* 99<sup>8</sup> and 69<sup>8</sup> are sexual references.
* “Rent Method” refers to the song “Seasons of Love” from the musical “{{w|Rent (musical)|Rent}}.” The song asks, “How do you measure a year?” One line says “525,600 minutes” while most of the rest of the song suggests the best way to measure a year is moments shared with a loved one.
* (202) 456-1415 was (at least during the Bush administration) the phone number for the White House switchboard. Randall's formula gives approximately 0.2024561415.
* Jenny's constant comes from Tommy Tutone's tune {{w|867-5309/Jenny}}. Randall's formula gives approximately 867.530901981685.
* {{w|42 (number)|42}} is, according to Douglas Adams' ''The Hitchhiker's Guide to the Galaxy'', the Answer to Life, the Universe, and Everything.

And here are some of the mathematical and physical ones, with Wikipedia links.

* Informally, the {{w|Planck constant}} is the smallest action possible in quantum mechanics.
* The {{w|fine structure constant}} indicates the strength of electromagnetism. It is unitless and around 0.007297, close to 1/137. At one point it was believed to be exactly the reciprocal of 137, and many people have tried to find a simple formula explaining this (with a pinch of {{w|numerology}} thrown in at times).
* In {{w|mathematics}}, the {{w|Euler-Mascheroni constant}} (Euler gamma constant) is a mysterious number describing the relationship between the {{w|Harmonic series (mathematics)|harmonic series}} and the {{w|natural logarithm}}.
* The {{w|gravitational constant}} relates to, uh, gravity.
* The {{w|gas constant}} relates energy to temperature in physics.
* ϕ is the {{w|golden ratio}}, or (1 + √5)/2. It has many interesting geometrical properties.
* The ruby laser wavelength varies because “ruby” is not clearly defined.
* The {{w|Earth radios#mean radii|mean earth radius}} varies because there is not one single way to make a sphere out of the earth. Randall's value lies within the actual variation of Earth's radius.

The correct equation in the "Pro tip - Not all of these are wrong" section is cos(pi/7) + cos(3pi/7) + cos(5pi/7) = 1/2 as [http://math.stackexchange.com/questions/140388/how-can-one-prove-cos-pi-7-cos3-pi-7-cos5-pi-7-1-2 shown here].

The number 8675309 at the title text refers to the song 867-5309/Jenny as mentioned above, causing a fad of people dialing this number and asking for "Jenny". The number is in fact a {{w|twin prime}} because 8675311 is also a prime. Twin primes have always been a subject of interest, because they are comparatively rare, and because it is not yet known whether there are infinitely many of them.

{{w|Pi}} is a natural constant that arises in describing circles or ellipses. As such, useful as it may be, it really shouldn't occur anywhere in an exponent (unless you deal with complex numbers).

Same goes for the e-th power: e typically appears in the basis of a power (forming the {{w|exponential function}}), not in the exponent.

The software referred to in the comic is [http://mrob.com/pub/ries/ ries], a 'reverse calculator' which forms equations matching a given number.

==Transcript==
A table of slightly wrong equations and identities useful for approximations and/or trolling teachers. (Found using a mix of trial-and-error, Mathematica, and Robert Munafo's Ries tool.) All units are SI MKS unless otherwise noted.

*Relation: One light year(m) ~= 99^8
Accurate to within: one part in 40

*Relation: Earth Surface(m^2) ~= 69^8
Accurate to within: one part in 130

*Relation: Ocean's volume(m^3) ~= 9^19
Accurate to within: one part in 70

*Relation: Seconds in a year ~= 75^4
Accurate to within: one part in 400

*Relation: Seconds in a year (rent method) ~= 525,600 x 60
Accurate to within: one part in 1400

*Relation: Age of the universe (seconds) ~= 15^15
Accurate to within: one part in 70

*Relation: Planck's constant ~= 1/(30^pi^e)
Accurate to within: one part in 110

*Relation: Fine structure constant ~= 1/140
Accurate to within: [I've had enough of this 137 crap]

*Relation: Fundamental charge ~= 3/(14 * pi^pi^pi)
Accurate to within: one part in 500

*Relation: White House Switchboard ~= 1/(e^((1 + 8^(1/(e-1)))^(1/pi)))

*Relation: Jenny's Constant ~= (7^(e/1 - 1/e) - 9) * pi^2

----
Intermission: World Population Estimate which should stay current for a decade or two:

Take the last two digits of the current year

Example: 20[14]

Subtract the number of leap years since hurricane Katrina

Example:14 (minus 2008 and 2012) is 12

Add a decimal point

Example: 1.2

Add 6

Example: 6 + 1.2

7.2 ~= World population in billions.

Version for US population:

Example: 20[14]

Subtract 10

Example: 4

Multiply by 3

Example: 12

Add 10

Example: 3[22] million
----

*Relation: Electron rest energy ~= e/7^16 Joules
Accurate to within: one part in 1000

*Relation: Light-year(miles) ~= 2^(42.42)
Accurate to within: one part in 1000

*Relation: sin(60 degrees) = (3^(1/2))/2 ~= e/pi
Accurate to within: one part in 1000

*Relation: 3^(1/2) ~= 2e/pi
Accurate to within: one part in 1000

*Relation: gamma(Euler's gamma constant) ~= 1/(3^(1/2))
Accurate to within: One part in 4000

*Relation: Feet in a meter ~= 5/(pi^(1/e))
Accurate to within: one part in 4000

*Relation: 5^(1/2) ~= 2/e + 3/2
Accurate to within: one part in 7000

*Relation: Avogadro's number ~= 69^pi^(5^(1/2))
Accurate to within: one part in 25,000

*Relation: Gravitational constant G ~= 1/(e^((pi - 1)^(pi + 1)))
Accurate to within: one part in 25,000

*Relation: R(gas constant) ~= (e+1) * (5^(1/2))
Accurate to within: one part in 50,000

*Relation: Proton-electron mass ratio ~= 6*pi^5
Accurate to within: one part in 50,000

*Relation: Liters in a gallon ~= 3 + pi/4
Accurate to within: one part in 500,000

*Relation: g ~= 6 + ln(45)
Accurate to within: one part in 750,000

*Relation: Proton-electron mass ratio ~= (e^8 - 10)/phi
Accurate to within: one part in 5,000,000

*Relation: Ruby laser wavelength ~= 1/(1200^2)
Accurate to within: [within actual variation]

*Relation: Mean Earth Radius ~= (5^8)*6e
Accurate to within: [within actual variation]

----
Protip - not all of these are wrong:

*2^(1/2) ~= 3/5 + pi/(7-pi)

*cos(pi/7) + cos(3pi/7) + cos(5pi/7) ~= 1/2

*gamma(Euler's gamma constant) ~= e/3^4 + e/5

*5^(1/2) ~= (13 + 4pi)/(24 - 4pi)

*sigma(1/n^n) ~= ln(3)^e

{{comic discussion}}
[[Category:Charts]]
[[Category:Math]]
[[Category:Physics]]
[[Category:Protip]]

1047: Approximations

2013-10-15T23:51:46Z

Anon: ries

{{comic
| number = 1047
| date = April 25, 2012
| title = Approximations
| image = approximations.png
| titletext = Two tips: 1) 8675309 is not just prime, it's a twin prime, and 2) if you ever find yourself raising log(anything)^e or taking the pi-th root of anything, set down the marker and back away from the whiteboard; something has gone horribly wrong.
}}

==Explanation==
{{incomplete}}
This comic lists some approximations for numbers, most of them mathematical and physical constants. All of them work astonishingly well. There are reoccurring math jokes along the lines of, “3/5 + π/(7 – π) – √2 = 0, but your calculator is probably not good enough to compute this correctly”, which are mainly used to troll geeks. Those interested in number theory may easily compute that sqrt(2) is not even algebraic in the quotient field of Z[pi], which disproves the equality.

Furthermore, there are some useful approximations (which were even more useful in times before calculators) such as “pi is approximately equal to 22/7”.

[[Randall]] makes fun of both of these, using rather strange approximations (honestly: you may handle 22/7, but who can calculate in a sensible way with 99^8, let alone 30^(pi^e)?) to calculate some constants that are easy enough to handle in the decimal system, and stating such “slightly wrong” trick equations, one of which ''is'' actually correct (which may astonish only those who are not familiar with cosines).

There are a few cultural references in this comic:

* 99<sup>8</sup> and 69<sup>8</sup> are sexual references.
* “Rent Method” refers to the song “Seasons of Love” from the musical “{{w|Rent (musical)|Rent}}.” The song asks, “How do you measure a year?” One line says “525,600 minutes” while most of the rest of the song suggests the best way to measure a year is moments shared with a loved one.
* (202) 456-1415 was (at least during the Bush administration) the phone number for the White House switchboard. Randall's formula gives approximately 0.2024561415.
* Jenny's constant comes from Tommy Tutone's tune {{w|867-5309/Jenny}}. Randall's formula gives approximately 867.530901981685.
* {{w|42 (number)|42}} is, according to Douglas Adams' ''The Hitchhiker's Guide to the Galaxy'', the Answer to Life, the Universe, and Everything.

And here are some of the mathematical and physical ones, with Wikipedia links.

* Informally, the {{w|Planck constant}} is the smallest action possible in quantum mechanics.
* The {{w|fine structure constant}} indicates the strength of electromagnetism. It is unitless and around 0.007297, close to 1/137. At one point it was believed to be exactly the reciprocal of 137, and many people have tried to find a simple formula explaining this (with a pinch of {{w|numerology}} thrown in at times).
* In {{w|mathematics}}, the {{w|Euler-Mascheroni constant}} (Euler gamma constant) is a mysterious number describing the relationship between the {{w|Harmonic series (mathematics)|harmonic series}} and the {{w|natural logarithm}}.
* The {{w|gravitational constant}} relates to, uh, gravity.
* The {{w|gas constant}} relates energy to temperature in physics.
* ϕ is the {{w|golden ratio}}, or (1 + √5)/2. It has many interesting geometrical properties.
* The ruby laser wavelength varies because “ruby” is not clearly defined.
* The {{w|Earth radios#mean radii|mean earth radius}} varies because there is not one single way to make a sphere out of the earth. Randall's value lies within the actual variation of Earth's radius.

The correct equation in the "Pro tip - Not all of these are wrong" section is cos(pi/7) + cos(3pi/7) + cos(5pi/7) = 1/2 as [http://math.stackexchange.com/questions/140388/how-can-one-prove-cos-pi-7-cos3-pi-7-cos5-pi-7-1-2 shown here].

The number 8675309 at the title text refers to the song 867-5309/Jenny as mentioned above, causing a fad of people dialing this number and asking for "Jenny". The number is in fact a {{w|twin prime}} because 8675311 is also a prime. Twin primes have always been a subject of interest, because they are comparatively rare, and because it is not yet known whether there are infinitely many of them.

{{w|Pi}} is a natural constant that arises in describing circles or ellipses. As such, useful as it may be, it really shouldn't occur anywhere in an exponent (unless you deal with complex numbers).

Same goes for the e-th power: e typically appears in the basis of a power (forming the {{w|exponential function}}), not in the exponent.

The software referred to in the comic is [http://mrob.com/pub/ries/ ries], a 'reverse calculator' which forms equations matching a given number.

==Transcript==
A table of slightly wrong equations and identities useful for approximations and/or trolling teachers. (Found using a mix of trial-and-error, Mathematica, and Robert Munafo's Ries tool.) All units are SI MKS unless otherwise noted.

*Relation: One light year(m) ~= 99^8
Accurate to within: one part in 40

*Relation: Earth Surface(m^2) ~= 69^8
Accurate to within: one part in 130

*Relation: Ocean's volume(m^3) ~= 9^19
Accurate to within: one part in 70

*Relation: Seconds in a year ~= 75^4
Accurate to within: one part in 400

*Relation: Seconds in a year (rent method) ~= 525,600 x 60
Accurate to within: one part in 1400

*Relation: Age of the universe (seconds) ~= 15^15
Accurate to within: one part in 70

*Relation: Planck's constant ~= 1/(30^pi^e)
Accurate to within: one part in 110

*Relation: Fine structure constant ~= 1/140
Accurate to within: [I've had enough of this 137 crap]

*Relation: Fundamental charge ~= 3/(14 * pi^pi^pi)
Accurate to within: one part in 500

*Relation: White House Switchboard ~= 1/(e^((1 + 8^(1/(e-1)))^(1/pi)))

*Relation: Jenny's Constant ~= (7^(e/1 - 1/e) - 9) * pi^2

----
Intermission: World Population Estimate which should stay current for a decade or two:

Take the last two digits of the current year

Example: 20[14]

Subtract the number of leap years since hurricane Katrina

Example:14 (minus 2008 and 2012) is 12

Add a decimal point

Example: 1.2

Add 6

Example: 6 + 1.2

7.2 ~= World population in billions.

Version for US population:

Example: 20[14]

Subtract 10

Example: 4

Multiply by 3

Example: 12

Add 10

Example: 3[22] million
----

*Relation: Electron rest energy ~= e/7^16 Joules
Accurate to within: one part in 1000

*Relation: Light-year(miles) ~= 2^(42.42)
Accurate to within: one part in 1000

*Relation: sin(60 degrees) = (3^(1/2))/2 ~= e/pi
Accurate to within: one part in 1000

*Relation: 3^(1/2) ~= 2e/pi
Accurate to within: one part in 1000

*Relation: gamma(Euler's gamma constant) ~= 1/(3^(1/2))
Accurate to within: One part in 4000

*Relation: Feet in a meter ~= 5/(pi^(1/e))
Accurate to within: one part in 4000

*Relation: 5^(1/2) ~= 2/e + 3/2
Accurate to within: one part in 7000

*Relation: Avogadro's number ~= 69^pi^(5^(1/2))
Accurate to within: one part in 25,000

*Relation: Gravitational constant G ~= 1/(e^((pi - 1)^(pi + 1)))
Accurate to within: one part in 25,000

*Relation: R(gas constant) ~= (e+1) * (5^(1/2))
Accurate to within: one part in 50,000

*Relation: Proton-electron mass ratio ~= 6*pi^5
Accurate to within: one part in 50,000

*Relation: Liters in a gallon ~= 3 + pi/4
Accurate to within: one part in 500,000

*Relation: g ~= 6 + ln(45)
Accurate to within: one part in 750,000

*Relation: Proton-electron mass ratio ~= (e^8 - 10)/phi
Accurate to within: one part in 5,000,000

*Relation: Ruby laser wavelength ~= 1/(1200^2)
Accurate to within: [within actual variation]

*Relation: Mean Earth Radius ~= (5^8)*6e
Accurate to within: [within actual variation]

----
Protip - not all of these are wrong:

*2^(1/2) ~= 3/5 + pi/(7-pi)

*cos(pi/7) + cos(3pi/7) + cos(5pi/7) ~= 1/2

*gamma(Euler's gamma constant) ~= e/3^4 + e/5

*5^(1/2) ~= (13 + 4pi)/(24 - 4pi)

*sigma(1/n^n) ~= ln(3)^e

{{comic discussion}}
[[Category:Charts]]
[[Category:Math]]
[[Category:Physics]]
[[Category:Protip]]

983: Privacy

2013-10-15T23:47:55Z

Anon: /* Explanation */

{{comic
| number = 983
| date = November 28, 2011
| title = Privacy
| image = privacy.png
| imagesize =
| titletext = Eventual headline: 'University Researchers Create Life in Lab! Darkness, Faulty Condoms Blamed.'
}}

==Explanation==
This comic is about [[Cueball]] and [[Megan]] attempting to find some privacy to "hook up", which is slang for engaging in sexual activity.

In the second frame, the female roommate of Megan's is currently in a {{w|Raid_(gaming)|raid}}, which is a phrase used in {{w|World of Warcraft}} and other {{w|Massively multiplayer online role-playing game|Massively Multiplayer Online Role Playing Games}} or MMORPGs. A Raid is a large gathering of players that work together to defeat a difficult enemy.

The Rare book collection in the library (frame 3) is usually deserted, so it would be perfect for sexual activity, but instead a tour is going through the area instead. It is unclear if the tour is visiting {{w|Nelson Mandela}} in the rare book section or Nelson Mandela is visiting the school and is getting a tour through the rare book section. Is that a stick figure Nelson Mandela with the white hair?

Next they try an accelerator tunnel that is in use, a beaver lodge (the word "beaver" may reference the slang term for the vulva). With our current understanding of physics, there is neither the possibility of {{w|hyperspace}} existing, nor the possibility of getting there quickly.

In the title text, it indicates that the two found privacy for sex in the lab, but inadvertently got Megan pregnant. The title text is a pun on news titles about scientists who have created synthetic life in the lab. This eventual headline appears in (some) [[1037: Umwelt]] frames as "Scientists Create Life In Lab".

[[658: Orbitals]] is similar.

==Transcript==
:Dorm:
:[An incredibly libidinous, extremely attractive couple try and enter one person's dorm room.]
:Locked.

:Other Dorm:
:[The same couple in the other person's dorm room, where the roommate is sitting at a computer playing an MMO]
:Roommate: I'll be done tuesday.
:Roommate in raid

:Library Rare Book Collection:
:[Libidinous couple staring inside the room from outside. Nelson Mandela and other university workers inside the room, looking at some extremely expensive items]
:Occupied by tour for visiting Nelson Mandela

:Accelerator Tunnel:
:[Couple stares at a heavy, imposing door denying them entry]
:Sealed while beam is in operation.

:Beaver Lodge (stop snickering!):
:[couple attempting to enter an occupied beaver lodge]
:Frozen over for winter to keep out predators; only accessible via underwater entrance.

:Hyperspace:
:[Couple in front of a number of highly advanced physics textbooks]
:Person 1: Are you ''sure?''
:Ruled out by current understanding of physics.

:College Law #27
:The availibilty [sic] of private space is inversely proportional to the desirability of the hookup.

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

1201: Integration by Parts

2013-08-14T21:48:58Z

Anon: 569

{{comic
| number = 1201
| date = April 19, 2013
| title = Integration by Parts
| image = integration by parts.png
| titletext = If you can manage to choose u and v such that u = v = x, then the answer is just (1/2)x^2, which is easy to remember. Oh, and add a '+C' or you'll get yelled at.
}}

==Explanation==
{{w|Integration by parts}} is an integration strategy that is used to evaluate difficult integrals by trying to find simpler integrals derived from the original. It is commonly a source of confusion or irritation for students when they first learn it, due to the fact that there is really no way to accurately predict the proper u/dv separation just by looking at an integral. Integration by parts requires patience, trial and error, and experience.

Randall shows a somewhat complicated math problem and, in an attempt to "help", simplifies it into a more compact integral. This is the first part of performing integration by parts, which involves the guessing. Having gotten it into integration by parts format, he then leaves without describing the actual solution. The general integral integral(u dv) is equal to uv - integral(v du), and this is the more tedious part of the math and where problems will arise if you picked the wrong u and dv at the beginning. The narrator makes a point of leaving here, so we can't ask for help or complain if the choice of u and dv was wrong.

In the title text, he points out that if the integral of x can be divided so that u = x and dv = dx (implying v = x), then it leads to the result (1/2)x^2 (implying the original integral was just ∫x dx, and not needing integration by parts in the first place). Mathematics teachers and extreme math geeks will also cringe at this answer, however, since an indefinite integral requires an integration constant. The correct answer is actually (1/2)x^2 + C, as Randall hints. The + C symbolizes that an integral can be shifted vertically any number (a constant) and still get the same answer. Definite integrals (which specify a specific range that they're valid on) do not have the added constant.

[[569: Borders]] makes a subtle reference to integration by parts (the name of the kingdom).

==Transcript==
:A Guide to
:Integration by Parts:

:Given a problem of the form:
::∫f(x)g(x)dx=?
:Choose variables u and v such that
::u=f(x)
::dv=g(x)dx
:Now the expression becomes:
::∫udv=?
:Which ''definitely'' looks easier.
:Anyway, I gotta run.
:But good luck!

{{comic discussion}}
[[Category:Math]]
[[Category:Sarcasm]]

1192: Humming

2013-08-14T21:45:08Z

Anon: 1199

{{comic
| number = 1192
| date = March 29, 2013
| title = Humming
| image = humming.png
| titletext = I'm so bad at carrying a tune, those 'find a song by humming its melody' websites throw an HTTP 406 error as soon as I start to hum.
}}

==Explanation==
Services like {{w|MusicBrainz}} and {{w|SoundHound}} can detect a recorded song's {{w|acoustic fingerprint}} and match it with an existing song. This lets them identify the title and artist of an unnamed recorded musical extract. In this comic, [[Megan]] hacks the acoustic fingerprint database to add her own entry with a message to [[Cueball]], in which she asks him to buy [[1022|cat food]].

HTTP error code 406 means Not Acceptable. When a client requests data from a server, the client lists the data formats that it can accept. If a server is unable to provide data in any format that the client accepts, the server returns error 406 Not Acceptable. For example, this can occur if a client requests XML but the server supports only JSON. In the comic, the standard meaning of the error message is ignored and the text "Not Acceptable" is taken literally: The server is offended by the author's humming.

[[1199: Silence]] further explores song identification.

==Transcript==
:[Megan is humming a tune.]
:Cueball: Hey.
:Cueball: What's that?

:[Megan is still humming the same tune.]
:Cueball: What are you humming?
:Cueball: Should I know the tune?
:Cueball: ...Hmm...

:[Cueball gets out his phone and opens up a music recognition program.]
:Phone: Identify song
:Phone: Recorded
:Phone: > Live [beta]

:Phone: Identifying...

:[A zoom in on the phone screen. An album cover with a picture of Megan on it.]
:Positive match:
:''Check it out!''
:By I hacked the audio fingerprint database
:Feat. MEEEEEE
:Track: We're out of cat food (pick some up?)

{{comic discussion}}
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]
[[Category:Music]]

1156: Conditioning

2013-08-14T21:18:43Z

Anon: 368

{{comic
| number = 1156
| date = January 4, 2013
| title = Conditioning
| image = conditioning.png
| titletext = 'Why are you standing in the yard wearing a papal hat and a robe covered in seeds?' 'Well, the Pope is visiting our town next month ...'
}}

==Explanation==
Herein, the author devises a method of addressing the issue of drivers who turn up their music to irritating levels which usually results in a lot of bass coming from the car - the low frequencies being the ones that most easily penetrate the car and travel further, thus being more audible to those around the car.

As the title suggests, the idea is to {{w|Classical conditioning|condition}} animals to respond to a thumping bass. The machine would work as follows: every few hours, the bass would turn on, and the box would dispense food behind an opening designed to look like an open car window. Over time, local wildlife would flock to the box to get the food from inside, and would soon realise that the bread crumbs are dispensed only after the subwoofer is activated. Eventually, the animals would associate a thumping bass with food, and would approach such a noise in groups.

The end result would be that the local wildlife would approach, and presumably attempt to enter, any car that has that same thumping bass. Drivers, in turn, would cease to turn up their music in order to prevent the groups of animals from chasing after their cars, thus solving the problem of annoyingly loud bass. This behavior modification can itself be seen as a {{w|Operant conditioning|somewhat different form of conditioning}}.

The title text is a dialogue about using a similar method of conditioning to send animals after the Pope.

[[368: Bass]] gives an alternate solution.

==Transcript==
:Every few hours, subwoofer plays throbbing bass for 10 seconds... (with arrow pointing to subwoofer)
:...then bread crumbs are dispensed into box (with arrow pointing to bread feeder machine)
:Opening (with arrow pointing to feeder opening shaped like a driver side car window)
:Local wildlife (with arrows pointing to birds and a squirrel)
:Protip: Leave this device in your yard for a week, then watch as the problem of loud music from passing cars solves itself.

{{comic discussion}}
[[Category:Biology]]
[[Category:Protip]]

1144: Tags

2013-08-14T21:11:56Z

Anon: 859

{{comic
| number = 1144
| date = December 7, 2012
| title = Tags
| image = tags.png
| titletext = <A>: Like </a>this.&nbsp;
}}

==Explanation==
{{w|HTML}} is a markup language used in web development, and is the subject of this comic. The comic employs multiple poor HTML practices while asking the rhetorical question of how best to annoy web developers, effectively answering the question that it poses.

First, in HTML, all tags should be matched with both an open and close tag of the same type <code><div>Like this</div></code>. Previous to HTML 4.01 all tags were uppercase (technically elements were uppercase and attributes were lowercase "to improve readability" [http://www.w3.org/TR/1998/REC-html40-19980424/about.html#h-1.2.1]) to make it easier on the browser to parse what was markup and what was content on the page. As is the case with nearly every change to the HTML specification, many developers slowly got lazy and stopped making every tag uppercase forcing browser developers to check for both upper and lowercase as they parsed the markup. When the specification was bumped to XHTML 1.0 it stated that no one should use uppercase tags any more, everything should be lowercase.

Another basic idea of HTML is that all tags, or elements, must be properly nested. (Although they have slightly different meanings, the words "elements" and "tags" are generally used interchangeably.) That is, anything inside a div must be closed before the div is closed.

{| class="wikitable" |
! Correct
! Incorrect
|-
|
<div>
<ol>
<li>Correctly nested</li>
</ol>
</div>
|
<div>
<ol>
<li>Incorrectly nested</li>
</div>
</ol>
|-
|}

Further, web developers make a distinction between ''semantic'' and ''structural'' elements. Semantic elements contain a clue in their name as to what kind of an element they are - for example, an <code><article></code> tag contains an article, such as a blog post or news article, while an <code><ol></code> tag contains an '''o'''rdered '''l'''ist. (It's wise to note that this is not an absolute rule; it's ''possible'' to put non-article content in an <code><article></code>, it's just not recommended.) Semantic tags do not, however, indicate how their contents are to be displayed; your browser might display an <code><article></code> in the default font, layout, and placement, while mine, a [http://en.wikipedia.org/wiki/Screen_reader screen reader], might ignore everything on the page <code><article></code>s, and read <code><article></code>s in a soothing voice.

Structural tags, on the other hand, give no clues as to what they contain; they just indicate how a web page is to be laid out. <code><span></code> and <code><div></code> are structural tags; they can contain anything. Their definitions in HTML simply indicate that <code><div></code> is a block tag - it can affect both what the text looks like and where it is on the page; by default, it is displayed in a separate block from the rest of the text in the page, and has at least one line break before and after its display - and <code><span></code> is an inline tag - it affects what its text looks like, but not where it is on the page. Without additional attributes, it's impossible for a browser to tell what's supposed to be inside a <code><div></code> or a <code><span></code>, which means that my screen reader can't just pluck out the blog posts and read those.

Currently, the standard of usage is shifting toward using semantic tags over structural tags, since they provide more information to browsers and people reading the source code of web pages. HTML5, the most recent version of the standard web development markup language, is introducing many semantically meaningful tags that can be styled using [http://en.wikipedia.org/wiki/Cascading_Style_Sheets CSS] to follow the same behavior as a div or span, but that are easier to understand when reading the markup or parsing it with a non-standard browser.

The title text makes reference to <code>&nbsp;</code>, which is the {{w|HTML#Character and entity references|HTML escape code}} for {{w|non-breaking space}} which is a type of space that will keep two words together, and will not allow word wrapping to separate them. If the words come at the end of a displayed line, how this is handled depends on the browser and on the element's styling; some browsers and styles will force the connected words onto a new line, while others will "overflow" the edge of the container to accommodate the linked words. This is useful, for example, for keeping units with a number so it is easy to spot 100 km instead of needing to hunt for 100<br/>km. Using a non-breaking space at the end of a line, without another word on its trailing end, is only useful in extremely rare and limited circumstances, and does not generally have a purpose.

The title text also uses an <code><A></code> tag, seemingly to indicate an answer. In fact, <code><A></code> is an anchor tag, which creates {{w|hyperlink}}s. It is not an answer tag. This tag is generally used with either the <code>href=</code> (which creates a link to another URL) or <code>name=</code> (which creates a named anchor on the page that can be linked to with <code>href=#</code>) attribute (but not generally both at once). In addition, the placement of <code><A></code> and <code><a></code> (the capitalization here is also irritating to a web developer who values consistency) indicates that ": Like " should be a link or named anchor, but "this." should not. Whether or not to include punctuation in an anchor is a matter of some debate among developers, but including excessive whitespace is generally frowned upon, and the anchor ''should'' include all of the relevant text.

[[859: (]] is another attempt to hijack this need for (semantic) closure.

==Transcript==
:<code><div>Q: How do you annoy a web developer?</span></code>

{{comic discussion}}

919: Tween Bromance

2013-08-14T21:07:56Z

Anon: 550

{{comic
| number = 919
| date = July 1, 2011
| title = Tween Bromance
| image = tween_bromance.png
| titletext = Verbiage. Va-jay-jay. Irregardless.
}}

==Explanation==
This comic is playing off the fact that people have words that drive them crazy or gross them out. Moist is a very common word that people have a strong dislike to. In this comic, [[Cueball]] seems to be dictating a "tween bromance" story or novel to [[Megan]], who is possibly typing it up. Cueball is including all the words that get to Megan in a sequence (including the final 3 words in the title text). The 3 words in the title text are said after Megan says "STOP IT! STOP IT!"

To go into more details:
*The first four words are {{w|portmanteaus}}:
**“[http://www.urbandictionary.com/define.php?term=Tween Tween]” means a pre-adolescent.
**“[http://www.urbandictionary.com/define.php?term=bromance Bromance]” means a close non-sexual friendship between two males.
**“[http://www.urbandictionary.com/define.php?term=guesstimate Guesstimate]” means an estimate made with very little information.
**“[http://www.urbandictionary.com/define.php?term=frenemy Frenemy]” means a mixture of a friend and a rival.
*“[http://www.urbandictionary.com/define.php?term=yiff Yiff]” is a word invented by the {{w|furry community}}, derived from the sound a fox makes during orgasm.
*“[http://www.urbandictionary.com/define.php?term=taint Taint]” is the part between the genitals and the anus in slang.
*“[http://www.urbandictionary.com/define.php?term=preggers Preggers]” a slang term for being pregnant.
*“{{Wiktionary|verbiage}}” is a fairly new usage of an older word, meaning too many words used to explain a subject.
*“[http://www.urbandictionary.com/define.php?term=va-jay-jay Va-jay-jay]” is just a way of saying “vagina”.
*“[http://www.urbandictionary.com/define.php?term=Irregardless Irregardless]” is a {{w|solecism}}.

Like this comic fills a sentence with (gross) neologisms, [[550: Density]] crams a sentence with memes.

==Transcript==
:[All of Cueball's lines are overlaid over the entire comic; the panels listed are merely the ones directly under each sentence fragment.]
:[Cueball is standing smugly behind Megan, who is seated in front of a computer and typing.]
:Cueball: By my guesstimate,

:Cueball: my frenemy yiffed so hard

:Cueball: her moist taint made
:[Megan's eye twitches.]

:Cueball: her panties preggers!
:Megan: ''STOP IT STOP IT!''

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Language]]
[[Category:Furries]]

914: Ice

2013-08-14T21:05:14Z

Anon: 749

{{comic
| number = 914
| date = June 20, 2011
| title = Ice
| image = ice.png
| titletext = On the plus side, she wrote "Welcome to the AAA Club!" in lipstick on the bathroom mirror, and left me a membership/roadside assistance card on the counter.
}}

==Explanation==
This comic is a reference to an old urban legend: a guy is drugged, then he awakes in an ice-filled bathtub only to discover one (or both) of their kidneys has been harvested by organ thieves [http://www.snopes.com/horrors/robbery/kidney.asp].

In the comic, the situation is reversed: [[Beret Guy]] (who has just bought some ice for a party) is drugged, and he awakes in a bathtub filled with kidneys, only to discover that his ice has been harvested by a thief.

The title text refers to a similar story where the victim is left a note by their captor or one-night stand that says "Welcome to the AIDS club". Rather than having been involuntarily infected with HIV/AIDS, the victim ([[Beret Guy]]) has been involuntarily enrolled in the {{w|American Automobile Association}} (AAA).

Kidney-harvesting schemes were also discussed in [[749: Study]].

==Transcript==
:[Beret Guy and Megan are setting up a party, with a snack table and a big banner reading "PARTY!"]
:Megan: Everything's ready...
:Megan: Except we're out of ice.
:Beret Guy: I'll get some!

:[Beret Guy is walking down the street past a building marked Save Mart, with a bag of ice over his shoulder. Danish is standing on the sidewalk calls to him.]
:Danish: Hey sexy. Where're you headed with all that ice?
:Beret Guy: A party!
:Danish: There's a ''better'' party up at my place.
:Beret Guy: But I—
:Danish: C'mon, one drink.

:The next morning...
:[Beret Guy rubs eyes groggily.]
:Beret Guy: ...ugh... Where am I?
:Beret Guy: I was supposed to—
:Beret Guy: —where's all my ice!?

:[Beret Guy looks down to find himself in a bathtub full of kidneys.]
:Beret Guy: '''AAAAAAAAAAAAAAAAAAAAAAAA'''

{{comic discussion}}
[[Category:Comics featuring Beret Guy]]
[[Category:Comics featuring Danish]]
[[Category:Comics featuring Megan]]
[[Category:Comics with color]]

677: Asshole

2013-08-14T21:04:20Z

Anon: SUV

{{comic
| number =677
| date =December 18, 2009
| title =Asshole
| image =asshole.png
| titletext =[Shortly thereafter, at a nearby bakery] ::CRASH:: ::RUMBLE:: ::VRRRRRR:: "... I don't know, officer. It just scooped up an entire rack of scones and drove away!"
}}

==Explanation==
SUVs are incredibly large personal vehicles with a massive amount of cargo space, and notorious gas-guzzlers. The stereotype is that SUV owners drive such massive cars because they're compensating for something. Upon hearing [[Cueball]] call him an asshole for driving an SUV, [[Beret Guy]], hoping to win peoples' approval, trades his SUV in at the dealership for a hybrid subcompact.

Hybrid sedans are vehicles that can be powered by both gasoline and electricity - that is, by plugging them into a wall socket between uses. The stereotype is that people drive them so that they can feel superior to others, and that's exactly what [[Megan]] says when Beret Guy drives past them a second time.

Annoyed, Beret Guy trades in his car a second time, this time to get a massive construction vehicle and smack them with it. In the title text, he also uses it to get himself a whole bunch of scones, one of Beret Guy's trademarks.

In some ways this is a role reversal of [[437: SUV]].

==Transcript==
:[A couple watches Beret Guy drive by in an SUV.]
:Cueball: Look at that asshole in his SUV, thinking he's so badass while he guzzles gas driving around suburbia.
:Beret Guy: Oh no! Am I an asshole? I hope not.

:[Beret Guy trades in his keys at the dealership.]

:[Now he is driving by in a hybrid sedan.]
:Megan: Look at that smug asshole thinking he's better than us because he drives a hybrid.
:Beret Guy: ...

:[He trades in his keys again.]

:[The couple is standing.]
:Off-panel: ''RUMBLE''

:[Beret Guy drives a backhoe in and smacks the couple out of the panel with the digger.]

:[He drives off, whistling.]

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Beret Guy]]