explain xkcd - User contributions [en]

950: Mystery Solved

2025-05-17T01:17:45Z

CKcoolidge:

{{comic
| number = 950
| date = September 12, 2011
| title = Mystery Solved
| image = mystery_solved.png
| titletext = The Roanoke Lost Colonists founded Roanoke, the Franklin Expedition reached the Pacific in 2009 when the Northwest Passage opened, and Jimmy Hoffa currently heads the Teamsters Union--he just started going by 'James'.
}}

==Explanation==
In this comic, aviation pioneer {{w|Amelia Earhart|Amelia Earhart's}} plane comes back to land after it went missing in 1937. It was presumed that Earhart was dead and that her plane went down into the ocean at some point during her journey, although various alternate theories have arisen since then, with no clear answer to the mystery. However, this comic proposes a much simpler explanation: there was no disappearance, it just took her 74 years to fly around the Earth. This explanation is simple, but impossible.

Earhart seems to think the person she is talking with is stupid for not comprehending such a simple answer, but in fact her explanation raises a multitude of other questions. Among them:
* How did it take so long for her to land? (She answers that the world is big, but it isn't so big that it takes 74 years to fly around it, even with 1937 technology. {{Citation needed}} Earhart had already completed the majority of her journey before disappearing, and had "only" to cross the Pacific Ocean -- with stops in Howland Island and Hawaii -- before returning to her point of origin in Oakland, California. Had her flight succeeded, she could have completed it within three days of when she was last seen.)
* How did she survive that long, apparently without aging?
* Why didn't her plane fall apart (as even one year of continuous flight would have induced considerable depreciation (wear and tear) on many of the plane's mechanical components, and Amelia Earhart could not have repaired the plane while flying it){{Citation needed}} or run out of fuel?
* Why didn't anyone else see her on her journey or at least detect her with radar?
* Why doesn't she know that a flight shouldn't take 74 years?

Another possibility is that she did not just fly around the earth, but flew very fast (near {{w|light speed}}) for 74 non-subjective years to return {{w|Twin paradox|without having aged much}}. However, this would not explain why she thinks it is a long trip around the earth, and it raises the additional questions of how she would accomplish this feat in a {{w|Lockheed Model 10 Electra|twin-engine monoplane}} and how no one else noticed any signs of her plane traveling near light speed, such as a 74-year-long sonic boom.

Earhart's disappearance gave birth to many conspiracy theories. One of these, which was explored in the TV series [http://memory-alpha.wikia.com/wiki/Star_Trek:_Voyager Star Trek: Voyager], involves [http://memory-alpha.wikia.com/wiki/The_37%27s_(episode) her being abducted] to another [http://memory-alpha.wikia.com/wiki/Delta_Quadrant part of the galaxy], where she was left in cryogenic stasis until found by the Voyager crew. Something similar could be the case here, having Earhart frozen by aliens until 2011.

The title text lists a few more deceptively mundane answers to long-unsolved mysteries that at first seem to dispel the questions with boring logic, but in fact raise more questions than they answer. The first is the lost colonists of {{w|Roanoke Colony|Roanoke}}, who were one of the first groups to come to North America, but then suddenly disappeared, leaving their colony untouched. The comic suggests that they simply left to found {{w|Roanoke, Virginia}}. Like all the other explanations in this comic, this doesn't explain how this simple solution became lost to public knowledge. It also doesn't explain why they abandoned their original colony, or how they made it to Roanoke, Virginia, which is more than 300 miles away, or where they were between when their colony was found abandoned in 1590 and when the future Roanoke, Virginia, was established over 200 years later, in the nineteenth century.

The second mystery in the title text, the {{w|Franklin's lost expedition|Franklin Expedition}}, was a British voyage in 1845 to study the {{w|Northwest Passage}} that also disappeared, somewhere in northern Canada. The text suggests that the expedition wasn't lost; it was still exploring and eventually found its way to the Pacific Ocean in 2009. This is impossible, because the men on the expedition would be long dead. As a side note, both of the Franklin Expedition ships were eventually found wrecked in the years after this comic was published: [http://www.cbc.ca/news/politics/franklin-expedition-ship-pieces-believed-discovered-in-arctic-1.2759925 one in 2014], and [https://www.theguardian.com/world/2016/sep/12/hms-terror-wreck-found-arctic-nearly-170-years-northwest-passage-attempt the other in 2016].

The final mystery is {{w|Jimmy Hoffa}}, the famous {{w|International Brotherhood of Teamsters|Teamsters Union}} leader who went missing in 1975 and declared dead in 1982 (possibly murdered). The comic says Jimmy simply opted to switch to the more formal version of his name; again, this raises the question of how such a thing would be possible without anyone noticing. From 1998-2022, so at the time of this comic's publication, the head of the Teamsters was in fact named {{w|James P. Hoffa|James Hoffa}} (he is Jimmy Hoffa's son and goes by "James P. Hoffa" professionally); the comic could be implying that the senior Hoffa is not only alive but actually impersonating his own son, which would raise the question of why the supposed "son" doesn't look suspiciously older than he claims to be.

==Transcript==
:[A twin prop airplane flies high overhead.]
:Off-screen person: What's that airplane?

:[The plane has landed (shown in gray in the background), and the pilot, wearing an aviator hat and goggles, is walking towards the crowd waving.]
:Off-screen person: Holy crap— Is that Amelia Earhart?

:[A close up of Amelia Earhart waving.]
:Amelia: Hey everyone! My flight was a success!
:Off-screen person: But... Where were you!?

:[A wide view of Amelia, she stops waving.]
:Amelia: I flew around the world!
:Off-screen person: But you disappeared in 1937!

:[A close up of Amelia Earhart.]
:Amelia: Right, to fly around the world.
:Off-screen person: It's 2011!
:Amelia: The world is big. It's a long flight.

:[A wide view of Amelia]
:Off-screen person:
::But you...
::It's not...
::I -
:Amelia: Can I talk to someone smarter?

==Trivia==
This is the first xkcd comic featuring [[Amelia Earhart]].

{{comic discussion}}

[[Category:Comics featuring Amelia Earhart]]
[[Category:Aviation]]

3067: SawStart

2025-04-29T13:54:17Z

CKcoolidge:

{{comic
| number = 3067
| date = March 24, 2025
| title = SawStart
| image = sawstart.png
| imagesize = 290x313px
| noexpand = true
| titletext = Unfortunately, SawStart is one-use-only. Once started, the blade cannot be stopped, and must be replaced with a fresh blade while the running one is carefully disposed of.
}}

==Explanation==
{{incomplete|Language is too informal.}}
{{w|SawStop}} is an American {{w|table saw}} manufacturer whose product is designed to increase safety. Table saws can be highly dangerous if not used properly, because they feature a rapidly spinning {{w|circular saw}} protruding from the surface. If any part of someone's body comes into contact with the blade while it's spinning, it can cause severe injury or death. In general, it is not wise to touch even a normal stopped blade without being absolutely certain that the power cannot be turned on and the blade is not sharp enough to be dangerous at rest. SawStop products feature an automatic brake, designed to detect when flesh comes into contact with the blade. According to manufacturer claims, the brake (an aluminum block) will stop the blade within 5 milliseconds of detecting contact, followed by the blade retracting into the table. This is intended to prevent major injuries in the event of contact.

Here, [[Black Hat]] takes the notion of a product designed to increase safety, and changes the design to do the opposite, making it much more dangerous. Like the SawStop design, his product ostensibly detects contact with skin and reacts within milliseconds, but rather than stopping the blade, his product uses an explosive charge to ''start'' a stationary blade. Simply turning a stationary blade on in the event of contact would be bad enough, but the explosive device implies very rapid acceleration. It might even work if the tool is turned off and unplugged (usually a safe condition for working with saw blades){{Citation needed}}. This 'feature' is specifically designed to run up to significantly damaging speeds the moment it is touched, likely causing severe injury. There is no benefit to such a system, and it exists solely to be malicious, which is likely why it's "less popular."

This product is highly inefficient and unsafe, given the inherent danger of a rapidly accelerating saw blade. However, another possibly more important issue exists with this product: cost. SawStart is likely priced similarly to SawStop (around $1200 as of the time of writing), and may be used weekly or even daily. The net cost would be $62 400 for the saws alone, and around $187 200 in hospital bills, assuming the user resides in New York and is using SawStart weekly.

{{w|Coffman engine starter|Using explosives}} to start a mechanism has been implemented in older piston-engined aircraft as well as in {{w|Field Marshall#Starting|tractors}}. This method was preferred in times when speed is a priority in starting a rotary mechanism, especially when electric starters were not an option. This has led to its use in the [https://www.af.mil/News/Article-Display/Article/121480/ B-52 bomber] nowadays.

The title text refers to the fact that the braking feature on the SawStop is single use. Because of the very fast response time, both the braking cartridge and the saw blade will be badly damaged in the process, and both will need to be replaced (this being considered preferable to the kinds of permanent injuries that can result from a spinning blade). The SawStart is also single use, but in its case, it somehow makes the blade impossible to stop, violating the second law of thermodynamics (and probably several other laws); perhaps SawStart is a partnership between Black Hat and [[Beret Guy]]'s business.. Hence, the SawStart blade must also be replaced and disposed of, but this apparently has to be done while the blade is spinning. To attempt to remove a spinning blade is incredibly dangerous, and this simply adds to the unnecessary harm this product could do. Disposal would also be complicated, because the still-spinning blade could cause damage to whatever is chosen to contain it.

A similar attempt at taking a safety feature and flipping it on its head was done in [[2876: Range Safety]], this time with the range safety officer being accompanied by a range danger officer.

==Transcript==
:[A table with a table saw stands behind Black Hat who gestures to the table while facing Megan and Cueball. There is a label on the side of the table, a logo of a circular saw blade, with the first part of a word inside the blade:]
:SawStart
:Black Hat: When the saw detects contact with skin, an explosive charge starts the blade spinning at full speed within a few milliseconds.

:[Caption below the panel:]
:SawStop's less-popular competitor

==Trivia==
In theory, such a system could be useful on a futuristic mechanized melee weapon (like "[[wikia:w:c:warhammer40k:Chainsword|chainswords]]" from ''{{w|Warhammer 40,000}}''). In that case, the saw would start spinning as soon as it hits the enemy, removing the need to allow time for it to spin up. On top of that, the saw is impossible to stop, and will continue to rip and shred any enemies in contact until the saw breaks. Such a combat disk saw may need to be redesigned so that it is activated by armor and flesh alike.

{{comic discussion}}

[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]

3067: SawStart

2025-04-29T13:53:53Z

CKcoolidge:

{{comic
| number = 3067
| date = March 24, 2025
| title = SawStart
| image = sawstart.png
| imagesize = 290x313px
| noexpand = true
| titletext = Unfortunately, SawStart is one-use-only. Once started, the blade cannot be stopped, and must be replaced with a fresh blade while the running one is carefully disposed of.
}}

==Explanation==
{{incomplete|Language is too informal.}}
{{w|SawStop}} is an American {{w|table saw}} manufacturer whose product is designed to increase safety. Table saws can be highly dangerous if not used properly, because they feature a rapidly spinning {{w|circular saw}} protruding from the surface. If any part of someone's body comes into contact with the blade while it's spinning, it can cause severe injury or death. In general, it is not wise to touch even a normal stopped blade without being absolutely certain that the power cannot be turned on and the blade is not sharp enough to be dangerous at rest. SawStop products feature an automatic brake, designed to detect when flesh comes into contact with the blade. According to manufacturer claims, the brake (an aluminum block) will stop the blade within 5 milliseconds of detecting contact, followed by the blade retracting into the table. This is intended to prevent major injuries in the event of contact.

Here, [[Black Hat]] takes the notion of a product designed to increase safety, and changes the design to do the opposite, making it much more dangerous. Like the SawStop design, his product ostensibly detects contact with skin and reacts within milliseconds, but rather than stopping the blade, his product uses an explosive charge to ''start'' a stationary blade. Simply turning a stationary blade on in the event of contact would be bad enough, but the explosive device implies very rapid acceleration. It might even work if the tool is turned off and unplugged (usually a safe condition for working with saw blades)[[Citation needed]]. This 'feature' is specifically designed to run up to significantly damaging speeds the moment it is touched, likely causing severe injury. There is no benefit to such a system, and it exists solely to be malicious, which is likely why it's "less popular."

This product is highly inefficient and unsafe, given the inherent danger of a rapidly accelerating saw blade. However, another possibly more important issue exists with this product: cost. SawStart is likely priced similarly to SawStop (around $1200 as of the time of writing), and may be used weekly or even daily. The net cost would be $62 400 for the saws alone, and around $187 200 in hospital bills, assuming the user resides in New York and is using SawStart weekly.

{{w|Coffman engine starter|Using explosives}} to start a mechanism has been implemented in older piston-engined aircraft as well as in {{w|Field Marshall#Starting|tractors}}. This method was preferred in times when speed is a priority in starting a rotary mechanism, especially when electric starters were not an option. This has led to its use in the [https://www.af.mil/News/Article-Display/Article/121480/ B-52 bomber] nowadays.

The title text refers to the fact that the braking feature on the SawStop is single use. Because of the very fast response time, both the braking cartridge and the saw blade will be badly damaged in the process, and both will need to be replaced (this being considered preferable to the kinds of permanent injuries that can result from a spinning blade). The SawStart is also single use, but in its case, it somehow makes the blade impossible to stop, violating the second law of thermodynamics (and probably several other laws); perhaps SawStart is a partnership between Black Hat and [[Beret Guy]]'s business.. Hence, the SawStart blade must also be replaced and disposed of, but this apparently has to be done while the blade is spinning. To attempt to remove a spinning blade is incredibly dangerous, and this simply adds to the unnecessary harm this product could do. Disposal would also be complicated, because the still-spinning blade could cause damage to whatever is chosen to contain it.

A similar attempt at taking a safety feature and flipping it on its head was done in [[2876: Range Safety]], this time with the range safety officer being accompanied by a range danger officer.

==Transcript==
:[A table with a table saw stands behind Black Hat who gestures to the table while facing Megan and Cueball. There is a label on the side of the table, a logo of a circular saw blade, with the first part of a word inside the blade:]
:SawStart
:Black Hat: When the saw detects contact with skin, an explosive charge starts the blade spinning at full speed within a few milliseconds.

:[Caption below the panel:]
:SawStop's less-popular competitor

==Trivia==
In theory, such a system could be useful on a futuristic mechanized melee weapon (like "[[wikia:w:c:warhammer40k:Chainsword|chainswords]]" from ''{{w|Warhammer 40,000}}''). In that case, the saw would start spinning as soon as it hits the enemy, removing the need to allow time for it to spin up. On top of that, the saw is impossible to stop, and will continue to rip and shred any enemies in contact until the saw breaks. Such a combat disk saw may need to be redesigned so that it is activated by armor and flesh alike.

{{comic discussion}}

[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]

3067: SawStart

2025-04-29T13:53:20Z

CKcoolidge:

{{comic
| number = 3067
| date = March 24, 2025
| title = SawStart
| image = sawstart.png
| imagesize = 290x313px
| noexpand = true
| titletext = Unfortunately, SawStart is one-use-only. Once started, the blade cannot be stopped, and must be replaced with a fresh blade while the running one is carefully disposed of.
}}

==Explanation==
{{incomplete|Language is too informal.}}
{{w|SawStop}} is an American {{w|table saw}} manufacturer whose product is designed to increase safety. Table saws can be highly dangerous if not used properly, because they feature a rapidly spinning {{w|circular saw}} protruding from the surface. If any part of someone's body comes into contact with the blade while it's spinning, it can cause severe injury or death. In general, it is not wise to touch even a normal stopped blade without being absolutely certain that the power cannot be turned on and the blade is not sharp enough to be dangerous at rest. SawStop products feature an automatic brake, designed to detect when flesh comes into contact with the blade. According to manufacturer claims, the brake (an aluminum block) will stop the blade within 5 milliseconds of detecting contact, followed by the blade retracting into the table. This is intended to prevent major injuries in the event of contact.

Here, [[Black Hat]] takes the notion of a product designed to increase safety, and changes the design to do the opposite, making it much more dangerous. Like the SawStop design, his product ostensibly detects contact with skin and reacts within milliseconds, but rather than stopping the blade, his product uses an explosive charge to ''start'' a stationary blade. Simply turning a stationary blade on in the event of contact would be bad enough, but the explosive device implies very rapid acceleration. It might even work if the tool is turned off and unplugged (usually a safe condition for working with saw blades)[Citation needed]. This 'feature' is specifically designed to run up to significantly damaging speeds the moment it is touched, likely causing severe injury. There is no benefit to such a system, and it exists solely to be malicious, which is likely why it's "less popular."

This product is highly inefficient and unsafe, given the inherent danger of a rapidly accelerating saw blade. However, another possibly more important issue exists with this product: cost. SawStart is likely priced similarly to SawStop (around $1200 as of the time of writing), and may be used weekly or even daily. The net cost would be $62 400 for the saws alone, and around $187 200 in hospital bills, assuming the user resides in New York and is using SawStart weekly.

{{w|Coffman engine starter|Using explosives}} to start a mechanism has been implemented in older piston-engined aircraft as well as in {{w|Field Marshall#Starting|tractors}}. This method was preferred in times when speed is a priority in starting a rotary mechanism, especially when electric starters were not an option. This has led to its use in the [https://www.af.mil/News/Article-Display/Article/121480/ B-52 bomber] nowadays.

The title text refers to the fact that the braking feature on the SawStop is single use. Because of the very fast response time, both the braking cartridge and the saw blade will be badly damaged in the process, and both will need to be replaced (this being considered preferable to the kinds of permanent injuries that can result from a spinning blade). The SawStart is also single use, but in its case, it somehow makes the blade impossible to stop, violating the second law of thermodynamics (and probably several other laws); perhaps SawStart is a partnership between Black Hat and [[Beret Guy]]'s business.. Hence, the SawStart blade must also be replaced and disposed of, but this apparently has to be done while the blade is spinning. To attempt to remove a spinning blade is incredibly dangerous, and this simply adds to the unnecessary harm this product could do. Disposal would also be complicated, because the still-spinning blade could cause damage to whatever is chosen to contain it.

A similar attempt at taking a safety feature and flipping it on its head was done in [[2876: Range Safety]], this time with the range safety officer being accompanied by a range danger officer.

==Transcript==
:[A table with a table saw stands behind Black Hat who gestures to the table while facing Megan and Cueball. There is a label on the side of the table, a logo of a circular saw blade, with the first part of a word inside the blade:]
:SawStart
:Black Hat: When the saw detects contact with skin, an explosive charge starts the blade spinning at full speed within a few milliseconds.

:[Caption below the panel:]
:SawStop's less-popular competitor

==Trivia==
In theory, such a system could be useful on a futuristic mechanized melee weapon (like "[[wikia:w:c:warhammer40k:Chainsword|chainswords]]" from ''{{w|Warhammer 40,000}}''). In that case, the saw would start spinning as soon as it hits the enemy, removing the need to allow time for it to spin up. On top of that, the saw is impossible to stop, and will continue to rip and shred any enemies in contact until the saw breaks. Such a combat disk saw may need to be redesigned so that it is activated by armor and flesh alike.

{{comic discussion}}

[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Cueball]]

1293: Job Interview

2025-04-14T04:38:21Z

CKcoolidge: Citation needed

{{comic
| number = 1293
| date = November 20, 2013
| title = Job Interview
| image = job_interview.png
| titletext = When you talk about the job experience you'll give me, why do you pronounce 'job' with a long 'o'?
}}

==Explanation==
Following on from [[1032: Networking|his attempts at networking]], [[Beret Guy]], the oddball of the xkcd cast, conducts an interview for a position at his mysterious company.

Much like most of Beret Guy's interactions with people, Beret Guy is cheerful and upbeat, yet indicates that he has at best a scrambled understanding of how people in this situation normally act. Because of this, the job interview becomes increasingly bizarre, starting with Beret Guy's assertion that the company headquarters is a "real building [he] found", implying that the building's reality might be in question. In addition, "finding" the building may imply that he does not own or rent it, but simply found it empty and moved in. He says his company makes "stuff for phones", but then adds, "like apps and stickers," two wildly different products in terms of both production and profitability {{Citation needed}}. He is strangely vague about both the position ("someone to write on our computers") and the salary ("a bunch of paychecks"). Then he mentions ghosts, which is either a powerful disincentive from joining the company, yet another sign that Beret Guy is mentally unsound, or both.

The strip finishes with Beret Guy plugging a cord into what appears to be an electrical outlet clumsily labeled "Soup," which then, implausibly, actually starts dispensing soup. Most electrical outlets do not function like this.{{Citation needed}} However, this is a typical behaviour of Beret Guy - see a similar example in: [[1395: Power Cord]]. It is possible that the electrical outlet is connected to a pipe which supplies soup from a soup reservoir or kitchen elsewhere in the facility, which would require the fixture to have a specialist valve-connector and the 'cable' to involve a pipe with a self-sealing end that 'keys' the valve open. It may even be more likely, given Beret Guy's 'abilities', that the outlet is taking electricity from a suitable power supply and the cord ultimately uses mass-energy conversion to turn it into soup; this would be in line with the possible operating mechanism of Beret Guy's water-creating dam in [[2710: Hydropower Breakthrough]].

The title text may be a reference to the biblical story of {{w|Job (biblical figure)|Job}} (pronounced with a long O to rhyme with globe), who was put through many horrendous ordeals to test his faith in God. This suggests that the interviewee will be taking on not a "job experience" but rather a "Job experience" (i.e. the job will be a horrendous ordeal).

==Transcript==
:[Beret Guy walks in, followed by Hairy.]
:Beret Guy: Welcome to our company! We're headquartered here, in this real building I found!

:[Both people sit down at a table. The 'hire' has a tray with food and a beverage. Beret Guy has a bowl. In the adjacent wall, there is a power outlet with a paper label taped to it marked "Soup". A small roll of wire sits next to Beret Guy's chair.]
:Hairy: What do you.. ''do''?
:Beret Guy: We make stuff for phones! Like apps and stickers.

:[Beret Guy grabs the roll of wire.]
:Beret Guy: We want to hire you to write on our computers. We can offer you a bunch of paychecks! There are ghosts here.

:[Beret Guy unrolls the wire and plugs it into the wall.]
:Hairy: ...Are you sure this is a company?
:Beret Guy: I hope so!

:[Soup streams out of the plugged-in wire into Beret Guy's bowl.]

{{comic discussion}}
[[Category:Comics featuring Hairy]]
[[Category:Comics featuring Beret Guy]]
[[Category:Strange powers of Beret Guy]]
[[Category:Beret Guy's Business]]
[[Category:Religion]]
[[Category:Job interviews]]
[[Category:Food]]
[[Category:Ghosts]]

Category:Cancer

2025-04-10T23:19:01Z

CKcoolidge:

[[Randall]]'s (then, fiancée) wife was diagnosed with Stage III breast cancer in October of 2010. He immediately immersed himself in research of what cancer was, what treatments were like, etc. Every once in a while, his research, and happenings with his family bubble to the surface in the form of a comic.

*[http://blog.xkcd.com/2010/11/05/submarines/ This] is the first mention of the cancer.
*[http://blog.xkcd.com/2011/06/30/family-illness/ Here] is a blog post from Randall in June 2011 with an update.

[[Category:Comics by topic|Comics by topic]]

You may also notice that the tone of these cancer-themed comics slowly gets happier. This could be due to a number of factors. We can only hope this means [[Randall Munroe]]'s wife is getting better.

[[Category:Biology]]

Talk:669: Experiment

2025-04-10T13:30:01Z

CKcoolidge:

I'm a science grad student, so these kinds of comics in particular I'm having fun writing for... (now if only I were writing my dissertation instead...) [[User:Bplimley|Bplimley]] ([[User talk:Bplimley|talk]]) 10:18, 7 April 2013 (UTC)
:You're turning these out really quickly. This is good stuff! '''[[User:Davidy22|{{Color|#707|David}}y²²]]'''[[User talk:Davidy22|<tt>[talk]</tt>]] 10:19, 7 April 2013 (UTC)
One can throw something to change one's motion in a frictionless vacuum.[[User:Username2|Username2]] ([[User talk:Username2|talk]]) 00:40, 27 July 2020 (UTC)
If the black hat REALLY cared about physics, he would have put a spherical cow inside the frictionless vacuum room. [[Special:Contributions/172.68.138.178|172.68.138.178]] 20:43, 7 March 2023 (UTC)
:the infinite plane of uniform density might be a reference to Nerd Sniping - [[User:Bb777|Bb777]] ([[User talk:Bb777|talk]]) 23:05, 2 March 2025 (UTC)
::[[356: Nerd Sniping]] - [[User:Bb777|Bb777]] ([[User talk:Bb777|talk]]) 23:06, 2 March 2025 (UTC)
I have a question about this comic. Correct me if I'm wrong, but friction isn't affected (or effected, see xkcd 326: Effect an Effect) by the presence of air, so wouldn't the physicist still be able to walk? He still would die, though, because you can only stay conscious in a vacuum for 10-15 seconds, and it would be nearly impossible to open the door in the vacuum.
[[User:CKcoolidge|CKcoolidge]] ([[User talk:CKcoolidge|talk]]) 03:22, 5 April 2025 (UTC)CKcoolidge
:It's basically a shortcut for "on a frictionless surface in a vacuum" (with possibly some other caveats, in some scenarios, depending upon exactly what's being modeled and why). If you think about it, the vacuum can't ever really ''have'' a friction at all (at least this side of some fairly exotic reactionless propulsion ideas), so best treat that interpretation as a tautology.
:That said, there are worse understandings. Like vacuum==weightlessness, or at least lunar-strength gravity, but the moment you're cycled through the airlock you have full 1G of gravity. A cinematic convention, of course, where you handwave the less SFX-based 'indoor' scenes, or handwave some gravity-plate dookickey, or the hard-SF ones lampshade with magnetic/velcro footwear (the 'badly hard-'SF ones might even grant things in earthbound vacuum chambers an undue weightlessness, with nary the briefest of nods to ''anti-''gravity generators somehow being coupled to the airlessness).
:Which of course makes a layman confused over what's realistic and what isn't. I suppose you could argue that Randall's choice of words could be better, but it ought to be a "YKWIM" situation for those like us who perhaps see what trope he's invoking, and shouldn't bother those who take the handwaving at first value without staring too deeply into that particular abyss. [[Special:Contributions/172.70.86.115|172.70.86.115]] 15:13, 5 April 2025 (UTC)
Ah, thank you for clarifying that so elegantly.
[[User:CKcoolidge|CKcoolidge]] ([[User talk:CKcoolidge|talk]]) 13:30, 10 April 2025 (UTC)CKcoolidge

669: Experiment

2025-04-05T03:32:58Z

CKcoolidge: /* Explanation */

{{comic
| number = 669
| date = November 30, 2009
| title = Experiment
| image = experiment.png
| titletext = The other two are still lost on the infinite plane of uniform density.
}}

==Explanation==
Problems in the study of {{w|kinematics}} often idealize the environment of the problem for the sake of simplicity. Specifically, it is assumed that objects are moving in a {{w|vacuum}} and that there is no {{w|friction}}. Then the complicated effects of air resistance and surface frictions can be ignored, and the more basic principles of momentum and energy can be explored. In more advanced physics, it is often easier or necessary to ignore friction if the process being studied is very complicated. So it could be said that "physics professors like working in a frictionless vacuum".

In the comic, [[Black Hat]] and [[Danish]] have interpreted that statement to mean that physics professors like doing their work while they are in a frictionless vacuum, instead of liking to work with problems which are set in a frictionless vacuum. Apparently, they have drugged a physics professor and put him in a glass dome (with his laptop so he can work) which they can evacuate and make frictionless. The professor wakes up confused from the drugs, and as the air is pumped out to make a vacuum (presumably slowly enough to prevent {{w|explosive decompression}} from coming into play), his words fade to silence because sound waves requires a substance such as air to travel through. As he starts to panic, he tries to run, presumably for the door we see in the last panels. However, without friction on the floor, he cannot exert any force to move forward, and his feet skate uselessly on the ground until he loses balance and falls. At this point he is probably suffering from {{w|asphyxiation}}. Black Hat and Danish are observing from outside the dome, and decide that physics professors have lied about liking to work in frictionless vacuums, even though they almost certainly knew that the physicist would die, {{Citation needed}} showcasing Black Hat's tendency to be a [[Classhole]].

The title text refers to another common idealization, of an infinite {{w|plane}} of uniform {{w|density}}. An infinite plane extends forever in two dimensions, which makes calculations easier because surface-related properties are identical everywhere. "Uniform density" could refer to the mass density of the plane, or more likely an {{w|electric charge}} density, which makes a common problem in basic {{w|electromagnetism}} involving calculating the {{w|electric field}}. The "other two physicists" that Black Hat and Danish are experimenting on are lost on the infinite plane, since there are no edges or landmarks anywhere to give them direction.

It should be noted that, although a vacuum can be approximated using a {{w|vacuum pump}}, {{w|frictionless plane|frictionless surfaces}} and infinite planes are only imaginary constructs and do not exist in our universe.{{Citation needed}}{{Actual citation needed|reason=A source for this could be interesting to read}}

==Transcript==
:[Darkness.]

:[Cueball is standing next to a laptop, looking groggy.]
:Cueball: Ugh...
:Cueball: What happened?

:[Cueball begins to regain some awareness, with his speech eventually fading out.]
:Cueball: Where am I?
:''FWOOOOOOSH''
:Cueball: Help! Someone help me (unintelligible speech due to loss of air in dome)

:[Cueball holds his hands to his mouth.]

:[Cueball looks shocked.]

:[Cueball tries to run, but has no traction against the ground.]

:[Cueball falls down.]

:[Cueball lies prone and motionless.]

:[Black Hat and Danish watching from outside the dome, with Black Hat holding a clipboard as if to take notes.]

:[Black Hat and Danish outside the dome. Black Hat is now holding the clipboard down to his side.]
:Black Hat: Huh. Looks like physics professors don't like working in frictionless vacuums after all.
:Danish: They're such liars.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Danish]]
[[Category:Physics]]

669: Experiment

2025-04-05T03:31:49Z

CKcoolidge: /* Explanation */

{{comic
| number = 669
| date = November 30, 2009
| title = Experiment
| image = experiment.png
| titletext = The other two are still lost on the infinite plane of uniform density.
}}

==Explanation==
Problems in the study of {{w|kinematics}} often idealize the environment of the problem for the sake of simplicity. Specifically, it is assumed that objects are moving in a {{w|vacuum}} and that there is no {{w|friction}}. Then the complicated effects of air resistance and surface frictions can be ignored, and the more basic principles of momentum and energy can be explored. In more advanced physics, it is often easier or necessary to ignore friction if the process being studied is very complicated. So it could be said that "physics professors like working in a frictionless vacuum".

In the comic, [[Black Hat]] and [[Danish]] have interpreted that statement to mean that physics professors like doing their work while they are in a frictionless vacuum, instead of liking to work with problems which are set in a frictionless vacuum. Apparently, they have drugged a physics professor and put him in a glass dome (with his laptop so he can work) which they can evacuate and make frictionless. The professor wakes up confused from the drugs, and as the air is pumped out to make a vacuum (presumably slowly enough to prevent {{w|explosive decompression}} from coming into play), his words fade to silence because sound waves requires a substance such as air to travel through. As he starts to panic, he tries to run, presumably for the door we see in the last panels. However, without friction on the floor, he cannot exert any force to move forward, and his feet skate uselessly on the ground until he loses balance and falls. At this point he is probably suffering from {{w|asphyxiation}}. Black Hat and Danish are observing from outside the dome, and decide that physics professors have lied about liking to work in frictionless vacuums, even though they almost certainly knew that the physicist would die, {{Citation needed}} showcasing Black Hat's tendency to be a {{Classhole}}.

The title text refers to another common idealization, of an infinite {{w|plane}} of uniform {{w|density}}. An infinite plane extends forever in two dimensions, which makes calculations easier because surface-related properties are identical everywhere. "Uniform density" could refer to the mass density of the plane, or more likely an {{w|electric charge}} density, which makes a common problem in basic {{w|electromagnetism}} involving calculating the {{w|electric field}}. The "other two physicists" that Black Hat and Danish are experimenting on are lost on the infinite plane, since there are no edges or landmarks anywhere to give them direction.

It should be noted that, although a vacuum can be approximated using a {{w|vacuum pump}}, {{w|frictionless plane|frictionless surfaces}} and infinite planes are only imaginary constructs and do not exist in our universe.{{Citation needed}}{{Actual citation needed|reason=A source for this could be interesting to read}}

==Transcript==
:[Darkness.]

:[Cueball is standing next to a laptop, looking groggy.]
:Cueball: Ugh...
:Cueball: What happened?

:[Cueball begins to regain some awareness, with his speech eventually fading out.]
:Cueball: Where am I?
:''FWOOOOOOSH''
:Cueball: Help! Someone help me (unintelligible speech due to loss of air in dome)

:[Cueball holds his hands to his mouth.]

:[Cueball looks shocked.]

:[Cueball tries to run, but has no traction against the ground.]

:[Cueball falls down.]

:[Cueball lies prone and motionless.]

:[Black Hat and Danish watching from outside the dome, with Black Hat holding a clipboard as if to take notes.]

:[Black Hat and Danish outside the dome. Black Hat is now holding the clipboard down to his side.]
:Black Hat: Huh. Looks like physics professors don't like working in frictionless vacuums after all.
:Danish: They're such liars.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Danish]]
[[Category:Physics]]

669: Experiment

2025-04-05T03:31:27Z

CKcoolidge: Made a citation needed

{{comic
| number = 669
| date = November 30, 2009
| title = Experiment
| image = experiment.png
| titletext = The other two are still lost on the infinite plane of uniform density.
}}

==Explanation==
Problems in the study of {{w|kinematics}} often idealize the environment of the problem for the sake of simplicity. Specifically, it is assumed that objects are moving in a {{w|vacuum}} and that there is no {{w|friction}}. Then the complicated effects of air resistance and surface frictions can be ignored, and the more basic principles of momentum and energy can be explored. In more advanced physics, it is often easier or necessary to ignore friction if the process being studied is very complicated. So it could be said that "physics professors like working in a frictionless vacuum".

In the comic, [[Black Hat]] and [[Danish]] have interpreted that statement to mean that physics professors like doing their work while they are in a frictionless vacuum, instead of liking to work with problems which are set in a frictionless vacuum. Apparently, they have drugged a physics professor and put him in a glass dome (with his laptop so he can work) which they can evacuate and make frictionless. The professor wakes up confused from the drugs, and as the air is pumped out to make a vacuum (presumably slowly enough to prevent {{w|explosive decompression}} from coming into play), his words fade to silence because sound waves requires a substance such as air to travel through. As he starts to panic, he tries to run, presumably for the door we see in the last panels. However, without friction on the floor, he cannot exert any force to move forward, and his feet skate uselessly on the ground until he loses balance and falls. At this point he is probably suffering from {{w|asphyxiation}}. Black Hat and Danish are observing from outside the dome, and decide that physics professors have lied about liking to work in frictionless vacuums, even though they almost certainly knew that the physicist would die, {{Citation needed}} showcasing Black Hat and Danish's tendency to be {{Classholes|Classhole}}.

The title text refers to another common idealization, of an infinite {{w|plane}} of uniform {{w|density}}. An infinite plane extends forever in two dimensions, which makes calculations easier because surface-related properties are identical everywhere. "Uniform density" could refer to the mass density of the plane, or more likely an {{w|electric charge}} density, which makes a common problem in basic {{w|electromagnetism}} involving calculating the {{w|electric field}}. The "other two physicists" that Black Hat and Danish are experimenting on are lost on the infinite plane, since there are no edges or landmarks anywhere to give them direction.

It should be noted that, although a vacuum can be approximated using a {{w|vacuum pump}}, {{w|frictionless plane|frictionless surfaces}} and infinite planes are only imaginary constructs and do not exist in our universe.{{Citation needed}}{{Actual citation needed|reason=A source for this could be interesting to read}}

==Transcript==
:[Darkness.]

:[Cueball is standing next to a laptop, looking groggy.]
:Cueball: Ugh...
:Cueball: What happened?

:[Cueball begins to regain some awareness, with his speech eventually fading out.]
:Cueball: Where am I?
:''FWOOOOOOSH''
:Cueball: Help! Someone help me (unintelligible speech due to loss of air in dome)

:[Cueball holds his hands to his mouth.]

:[Cueball looks shocked.]

:[Cueball tries to run, but has no traction against the ground.]

:[Cueball falls down.]

:[Cueball lies prone and motionless.]

:[Black Hat and Danish watching from outside the dome, with Black Hat holding a clipboard as if to take notes.]

:[Black Hat and Danish outside the dome. Black Hat is now holding the clipboard down to his side.]
:Black Hat: Huh. Looks like physics professors don't like working in frictionless vacuums after all.
:Danish: They're such liars.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Black Hat]]
[[Category:Comics featuring Danish]]
[[Category:Physics]]

Talk:669: Experiment

2025-04-05T03:25:08Z

CKcoolidge:

Talk:669: Experiment

2025-04-05T03:22:24Z

CKcoolidge: Asked a question about the comic.