explain xkcd - User contributions [en]

3041: Unit Circle

2025-01-23T01:48:49Z

172.70.85.6: /* Explanation */

{{comic
| number = 3041
| date = January 22, 2025
| title = Unit Circle
| image = unit_circle_2x.png
| imagesize = 325x259px
| noexpand = true
| titletext = They're continuing to search for a square with the same area as the circle, as efforts to construct one have run into difficulties.
}}

==Explanation==
{{incomplete|Constructed by a COMPASS AND STRAIGHTEDGE. Do NOT delete this tag too soon.}}
A {{w|unit circle}} is a mathematical concept, a circle whose radius is one (with no units). When doing math problems with a unit circle, all other distances are therefore in terms of the circle's radius: a line with length 3 is three times the radius, a line of length 1/2 is half the radius, and so on. This is very useful in many geometry problems.

This comic shows an expedition of some experts having located a "real unit circle": a physical object which somehow is this mathematical idea. By measuring the "real unit circle", mathematicians could then provide its measurement in whatever ordinary unit they choose, such as centimeters or inches, to textbooks which describe the unit circle. Doing so would be entirely pointless, as the entire purpose of the unit circle is that its radius is one unit, and it is not meant to correspond to any physical object.

The title text refers to the old geometry problem of {{w|squaring the circle}}: "constructing" (a term which here means drawing using only an idealized compass and straightedge) a square of area equal to a given circle, which would be π units square, thus having sides of √π units length. This has been proven to be impossible but, given the in-universe existence of the unit circle, perhaps such a square is ''also'' extant and just waiting to be found (though is different from the {{w|unit square}}, which is of course 1/π times the area of ''either'' of the other objects).

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

:[In a single panel, White Hat, Ponytail, Miss Lenhart, Cueball, and Megan are standing in a field. Ponytail is holding a notebook and taking notes, Miss Lenhart is kneeling and holding her hands on a circular object with the radius marked on it, Cueball is holding a large caliper-like measuring instrument, and Megan is taking a photo with her phone sideways.]

:[Caption below the panel:]
:Math breakthrough: Dimensional analysts have discovered a real unit circle. Once they measure it, units can finally be added to all our geometry textbooks.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Comics featuring Miss Lenhart]]
[[Category:Comics featuring White Hat]]
[[Category:Math]]
[[Category:Geometry]]

Talk:2950: Situation

2024-06-27T11:21:17Z

172.70.85.6: Tyop

For reference, the bridge in question is the Tacoma Narrows Bridge. [[User:Trimeta|Trimeta]] ([[User talk:Trimeta|talk]]) 18:57, 24 June 2024 (UTC)
:Noting that in all cases ''except'' the Tacoma Narrows, the design flaws were but a part of the issue, with operational decisions at the time playing a big part in the designed-in risks becoming reasons for an actual incident. The bridge could never have been "run safely", once built, unlike trying to ignore bunker fires whilst speeding through iceberg-alley or conducting stress tests in parallel with other non-standard procedures or just not refusing to conduct flights under certain weather conditions. Yes, the other things, by skipping the 'bad end' they actually had, would still be susceptible to future incidents (lessons not now having been properly learnt, or even known to be learnable, so still liable to being mishandled).
:But the only thing that could have saved the Tacoma bridge was to have been so much more alert (and less 'amused') by Galloping Gerti and immediately rushed into developing the better analytical models that could lead to an expensive in-situ retrofit (as with the Millenium Bridge, across the Thames, though that didn't have unavoidable wind issues and ''could'' be managed 'at leisure', whilst being made safer). And, without the rather spectacular demonstration of failure, it was probably not on the cards to 'not do nothing', even if it wasn't already too late to avert history in any reasonable way.
:It's human hubris/failings (at various levels) in each case, of course. But operational and design-time errors do more damage in combination than either by themselves. (Case in point, no deaths from the bridge collapse... actually handled pretty well, considering.) [[Special:Contributions/172.70.162.186|172.70.162.186]] 22:00, 24 June 2024 (UTC)

And for the record, the Challenger engineers *did* warn about the O-ring risk, but were overridden by management. [[Special:Contributions/172.68.35.95|172.68.35.95]] 19:25, 24 June 2024 (UTC)

It would have been so easy to draw a dam about to burst just behind the ocean liner {{unsigned ip|172.70.43.54|20:22, 24 June 2024}}
:Any particular dam-burst? There are many, but I'm not sure that we have an 'iconic' one... There's perhaps Taum Sauk, Vajont Dam, Brumadinho dam, El Cobre, Uttarakhand, Dale Dike Reservoir or Derna, picking a selection of notable ones. You couldn't count the deliberate Operation Chastise breaches or the (probably-)deliberate Kakhovka Dam one, nor all those 'nearly a disaster' ones (like Ulley and Toddbrook, two relatively recent concerns in the UK). [[Special:Contributions/172.70.162.186|172.70.162.186]] 22:00, 24 June 2024 (UTC)
::For whatever reason, the first thing that springs to my mind, is the flood scene from Team America World Police. [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 07:02, 25 June 2024 (UTC)
::Johnstown Flood is what came to mind, caused by the South Fork Dam is the most iconic US one, and long enough ago to joke about relative to more recent, larger ones [[Special:Contributions/162.158.159.140|162.158.159.140]] 16:52, 25 June 2024 (UTC)
::Also a huge molasses tank would have been a good reference to one of the worst non-water floods https://en.wikipedia.org/wiki/List_of_non-water_floods [[Special:Contributions/172.70.43.140|172.70.43.140]] 17:07, 25 June 2024 (UTC)

Winds caused by maintenance on a nuclear reactor... What? [[Special:Contributions/172.69.208.173|172.69.208.173]] 22:46, 24 June 2024 (UTC)
:Yeah, this explanation text is reaching, hard. [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 07:00, 25 June 2024 (UTC)

Calling what leaked from the O-ring 'fuel' somewhat understates the issue. The O-ring failure let the SRB rocket exhaust itself burn through and damage the attachment strut and the external tank. [[User:Dkfenger|Dkfenger]] ([[User talk:Dkfenger|talk]]) 23:11, 24 June 2024 (UTC)
:But, rocket fuel can't melt metal struts! ;S [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 06:58, 25 June 2024 (UTC)
::But it can get it hot enough that it then rips apart, causing other failures. [[User:SDSpivey|SDSpivey]] ([[User talk:SDSpivey|talk]]) 15:09, 25 June 2024 (UTC)
:::That was sarcasm, silly. ;P [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 18:38, 25 June 2024 (UTC)

I can't help but think that the ship/bridge combination also refers to the Key Bridge collapse, given that MV ''Dali'' just left Baltimore today, passing through the wreckage of the Key Bridge and under a Chesapeake Bay Bridge temporarily closed to traffic. --[[Special:Contributions/172.71.222.92|172.71.222.92]] 03:01, 25 June 2024 (UTC)
:Not shown: Ship electrical system with redundant buses, multiple breaker trips, and all bus ties closed. Not existent: Dolphins and breakers surrounding the piers of a fracture-critical bridge. [[Special:Contributions/172.70.175.84|172.70.175.84]] 03:52, 25 June 2024 (UTC)
:Nothing in the comic implies anything about the Key Bridge. Coincidence of timing, at best. [[User:SDSpivey|SDSpivey]] ([[User talk:SDSpivey|talk]]) 15:09, 25 June 2024 (UTC)

I feel like there's potential here, for a Rock-Paper-Scissors-Lizard-Spock kind of game, where each disaster can cause two others & prevent two others. [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 07:07, 25 June 2024 (UTC)

50 comics until 3000! [[user talk:lettherebedarklight|youtu.be/miLcaqq2Zpk]] 04:06, 25 June 2024 (UTC)

In the section labeled "Hydrogen-filled [...] Airship [...]", should we remove the ellipses and show the entire label instead? Is there a good reason for not showing the full label? [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 15:02, 26 June 2024 (UTC)
:I'm going to be bold and change this to the full label. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 15:08, 26 June 2024 (UTC)

I'm going to hazard a conjecture that the reactor kicked off the whole megadisaster when it exploded. The enormous blast from the explosion caused the bridge to collapse. It fell over on the airship and exploded it, and the ocean liner, without its trusty iceberg scout, sank (either on an iceberg or on one of the numerous pieces of wreckage from the bridge or airship). Feel free to use it if it seems plausible. {{unsigned ip|172.69.34.129|20:46, 26 June 2024}}

Why doesn't this page have a "next" button at the top? Or is that only happenning for me? --[[Special:Contributions/172.70.162.186|172.70.162.186]] 09:31, 27 June 2024 (UTC)
:It does for me. But note that the mechanism to give a Next button to every page ''except the very latest'' has been tardy in responding (or being cache-updated, I think was the issue) before. It's possible you saw it before the background whatever-needs-to-be-done was done, but it seems fixed now.
:It's also a possibility that ''your'' local cache is(/was) being tardy (or even some intervening cloud-cache is 'ruining your day'), but if you can see your comment (and this reply) in the "Discussion" footer of the main comic page than I would say you certainly should be getting the updated page in every respect, including the Next-linking button to 2951.
:If you find that it's still ''not'' the case then let us know. If you need to to to the Talk page to even see this, then perhaps we can also help suggest ways to get it moving. But it should still resolve soon enough, I imagine. [[Special:Contributions/172.70.85.6|172.70.85.6]] 11:20, 27 June 2024 (UTC)

Talk:2950: Situation

2024-06-27T11:20:42Z

172.70.85.6:

For reference, the bridge in question is the Tacoma Narrows Bridge. [[User:Trimeta|Trimeta]] ([[User talk:Trimeta|talk]]) 18:57, 24 June 2024 (UTC)
:Noting that in all cases ''except'' the Tacoma Narrows, the design flaws were but a part of the issue, with operational decisions at the time playing a big part in the designed-in risks becoming reasons for an actual incident. The bridge could never have been "run safely", once built, unlike trying to ignore bunker fires whilst speeding through iceberg-alley or conducting stress tests in parallel with other non-standard procedures or just not refusing to conduct flights under certain weather conditions. Yes, the other things, by skipping the 'bad end' they actually had, would still be susceptible to future incidents (lessons not now having been properly learnt, or even known to be learnable, so still liable to being mishandled).
:But the only thing that could have saved the Tacoma bridge was to have been so much more alert (and less 'amused') by Galloping Gerti and immediately rushed into developing the better analytical models that could lead to an expensive in-situ retrofit (as with the Millenium Bridge, across the Thames, though that didn't have unavoidable wind issues and ''could'' be managed 'at leisure', whilst being made safer). And, without the rather spectacular demonstration of failure, it was probably not on the cards to 'not do nothing', even if it wasn't already too late to avert history in any reasonable way.
:It's human hubris/failings (at various levels) in each case, of course. But operational and design-time errors do more damage in combination than either by themselves. (Case in point, no deaths from the bridge collapse... actually handled pretty well, considering.) [[Special:Contributions/172.70.162.186|172.70.162.186]] 22:00, 24 June 2024 (UTC)

And for the record, the Challenger engineers *did* warn about the O-ring risk, but were overridden by management. [[Special:Contributions/172.68.35.95|172.68.35.95]] 19:25, 24 June 2024 (UTC)

It would have been so easy to draw a dam about to burst just behind the ocean liner {{unsigned ip|172.70.43.54|20:22, 24 June 2024}}
:Any particular dam-burst? There are many, but I'm not sure that we have an 'iconic' one... There's perhaps Taum Sauk, Vajont Dam, Brumadinho dam, El Cobre, Uttarakhand, Dale Dike Reservoir or Derna, picking a selection of notable ones. You couldn't count the deliberate Operation Chastise breaches or the (probably-)deliberate Kakhovka Dam one, nor all those 'nearly a disaster' ones (like Ulley and Toddbrook, two relatively recent concerns in the UK). [[Special:Contributions/172.70.162.186|172.70.162.186]] 22:00, 24 June 2024 (UTC)
::For whatever reason, the first thing that springs to my mind, is the flood scene from Team America World Police. [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 07:02, 25 June 2024 (UTC)
::Johnstown Flood is what came to mind, caused by the South Fork Dam is the most iconic US one, and long enough ago to joke about relative to more recent, larger ones [[Special:Contributions/162.158.159.140|162.158.159.140]] 16:52, 25 June 2024 (UTC)
::Also a huge molasses tank would have been a good reference to one of the worst non-water floods https://en.wikipedia.org/wiki/List_of_non-water_floods [[Special:Contributions/172.70.43.140|172.70.43.140]] 17:07, 25 June 2024 (UTC)

Winds caused by maintenance on a nuclear reactor... What? [[Special:Contributions/172.69.208.173|172.69.208.173]] 22:46, 24 June 2024 (UTC)
:Yeah, this explanation text is reaching, hard. [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 07:00, 25 June 2024 (UTC)

Calling what leaked from the O-ring 'fuel' somewhat understates the issue. The O-ring failure let the SRB rocket exhaust itself burn through and damage the attachment strut and the external tank. [[User:Dkfenger|Dkfenger]] ([[User talk:Dkfenger|talk]]) 23:11, 24 June 2024 (UTC)
:But, rocket fuel can't melt metal struts! ;S [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 06:58, 25 June 2024 (UTC)
::But it can get it hot enough that it then rips apart, causing other failures. [[User:SDSpivey|SDSpivey]] ([[User talk:SDSpivey|talk]]) 15:09, 25 June 2024 (UTC)
:::That was sarcasm, silly. ;P [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 18:38, 25 June 2024 (UTC)

I can't help but think that the ship/bridge combination also refers to the Key Bridge collapse, given that MV ''Dali'' just left Baltimore today, passing through the wreckage of the Key Bridge and under a Chesapeake Bay Bridge temporarily closed to traffic. --[[Special:Contributions/172.71.222.92|172.71.222.92]] 03:01, 25 June 2024 (UTC)
:Not shown: Ship electrical system with redundant buses, multiple breaker trips, and all bus ties closed. Not existent: Dolphins and breakers surrounding the piers of a fracture-critical bridge. [[Special:Contributions/172.70.175.84|172.70.175.84]] 03:52, 25 June 2024 (UTC)
:Nothing in the comic implies anything about the Key Bridge. Coincidence of timing, at best. [[User:SDSpivey|SDSpivey]] ([[User talk:SDSpivey|talk]]) 15:09, 25 June 2024 (UTC)

I feel like there's potential here, for a Rock-Paper-Scissors-Lizard-Spock kind of game, where each disaster can cause two others & prevent two others. [[User:ProphetZarquon|ProphetZarquon]] ([[User talk:ProphetZarquon|talk]]) 07:07, 25 June 2024 (UTC)

50 comics until 3000! [[user talk:lettherebedarklight|youtu.be/miLcaqq2Zpk]] 04:06, 25 June 2024 (UTC)

In the section labeled "Hydrogen-filled [...] Airship [...]", should we remove the ellipses and show the entire label instead? Is there a good reason for not showing the full label? [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 15:02, 26 June 2024 (UTC)
:I'm going to be bold and change this to the full label. [[User:Ianrbibtitlht|Ianrbibtitlht]] ([[User talk:Ianrbibtitlht|talk]]) 15:08, 26 June 2024 (UTC)

I'm going to hazard a conjecture that the reactor kicked off the whole megadisaster when it exploded. The enormous blast from the explosion caused the bridge to collapse. It fell over on the airship and exploded it, and the ocean liner, without its trusty iceberg scout, sank (either on an iceberg or on one of the numerous pieces of wreckage from the bridge or airship). Feel free to use it if it seems plausible. {{unsigned ip|172.69.34.129|20:46, 26 June 2024}}

Why doesn't this page have a "next" button at the top? Or is that only happenning for me? --[[Special:Contributions/172.70.162.186|172.70.162.186]] 09:31, 27 June 2024 (UTC)
:It does for me. But note that the mechanism to give a Next button to every page ''exceot the very latest'' has been tardy in responding (or being cache-updated, I think was the issue) before. It's possible you saw it before the background whatever-needs-to-be-done was done, but it seems fixed now.
:It's also a possibility that ''your'' local cache is(/was) being tardy (or even some intervening cloud-cache is 'ruining your day'), but if you can see your comment (and this reply) in the "Discussion" footer of the main comic page than I would say you certainly should be getting the updated page in every respect, including the Next-linking button to 2951.
:If you find that it's still ''not'' the case then let us know. If you need to to to the Talk page to even see this, then perhaps we can also help suggest ways to get it moving. But it should still resolve soon enough, I imagine. [[Special:Contributions/172.70.85.6|172.70.85.6]] 11:20, 27 June 2024 (UTC)

320: 28-Hour Day

2024-06-27T08:50:29Z

172.70.85.6: Clear error, as 126!=168

{{comic
| number = 320
| date = September 24, 2007
| title = 28-Hour Day
| image = 28_hour_day.png
| titletext = Small print: this schedule will eventually drive one stark raving mad.
}}

==Explanation==
The {{W|Circadian rhythm#Enforced longer or shorter cycles|28-Hour Day}} is a modified sleep schedule proposed to accommodate the discrepancy between the earth's day-night cycle and certain people's preferred sleep schedules. It discards the traditional notion of sleeping at night and replaces it with sleeping when it is more convenient for weekend parties and mid-week insomnia. It is also the only reasonable and consistent alternative day length that will sync with the widely accepted and practiced 168-hour week (168 = 7×24 = 6×28), with the arguable exception of eight 21-hour days. Underneath the weekly timeline, [[Cueball]] describes the schedule's selling points to his friend, who apparently has difficulty sleeping.

Cueball's friend shows little interest in this idea, and instead he resorts to low-quality "your mom" jokes. Cueball merely bides his time, and in the end successfully trumps the jokes with a response that impugns his friend's sexual stamina, leading him to concede defeat.

The title-text uses "{{w|Fine_Print|Small print}}" to mean "Disclaimer" and relieves the idea's creator of any responsibility in the case that it is tried and the tester finds the schedule to be a really bad idea. As he states, if you live by this schedule, chances are you will be driven stark raving mad. Given that Cueball gives his friend with the bad mom jokes this advice, it could be another way to try to punish him for the jokes. Although Randall makes several [[:Category:Your Mom|Your Mom comics]], he has also in some comics shown that he dislikes these kind of jokes, especially when used too much in real life (see [[366: Your Mom]].)

==Schedule==
{| class="wikitable collapsible collapsed"
!colspan=5|28-Hour Day Schedule
|-
!Day
!Time
!28-Hour Schedule
!Normal 24 hour day
|-
| rowspan=12|Sunday||style="text-align:right;"|12:00 AM||
|rowspan=3 nobreak|Normal night from 6 PM to 6 AM
|-
| style="text-align:right;"|2:00 AM||
|-
| style="text-align:right;"|4:00 AM||
|-
| style="text-align:right;"|6:00 AM||||
|-
| style="text-align:right;"|8:00 AM||||
|-
| style="text-align:right;"|10:00 AM
|rowspan=4|Sleep
|
|-
| style="text-align:right;"|12:00 PM||
|-
| style="text-align:right;"|2:00 PM||
|-
| style="text-align:right;"|4:00 PM||
|-
| style="text-align:right;"|6:00 PM||
|rowspan=6|Normal night from 6 PM to 6 AM
|-
| style="text-align:right;"|8:00 PM||
|-
| style="text-align:right;"|10:00 PM||
|-
| rowspan=12|Monday||style="text-align:right;"|12:00 AM||
|-
|style="text-align:right;"|2:00 AM||
|-
| style="text-align:right;"|4:00 AM||
|-
| style="text-align:right;"|6:00 AM||||
|-
|style="text-align:right;"|8:00 AM||||
|-
| style="text-align:right;"|10:00 AM||||
|-
| style="text-align:right;"|12:00 PM||||
|-
| style="text-align:right;"|2:00 PM
|rowspan=4|Sleep
|
|-
| style="text-align:right;"|4:00 PM||
|-
| style="text-align:right;"|6:00 PM
|rowspan=6|Normal night from 6 PM to 6 AM
|-
| style="text-align:right;"|8:00 PM
|-
| style="text-align:right;"|10:00 PM||
|-
| rowspan=12|Tuesday||style="text-align:right;"|12:00 AM||
|-
| style="text-align:right;"|2:00 AM||
|-
| style="text-align:right;"|4:00 AM||
|-
| style="text-align:right;"|6:00 AM||||
|-
| style="text-align:right;"|8:00 AM||||
|-
| style="text-align:right;"|10:00 AM||||
|-
| style="text-align:right;"|12:00 PM||||
|-
| style="text-align:right;"|2:00 PM||||
|-
| style="text-align:right;"|4:00 PM||||
|-
| style="text-align:right;"|6:00 PM
|rowspan=4|Sleep
|rowspan=6|Normal night from 6 PM to 6 AM
|-
| style="text-align:right;"|8:00 PM
|-
| style="text-align:right;"|10:00 PM
|-
| rowspan=12|Wednesday||style="text-align:right;"|12:00 AM
|-
| style="text-align:right;"|2:00 AM||
|-
| style="text-align:right;"|4:00 AM||
|-
| style="text-align:right;"|6:00 AM||||
|-
| style="text-align:right;"|8:00 AM||||
|-
| style="text-align:right;"|10:00 AM||||
|-
| style="text-align:right;"|12:00 PM||||
|-
| style="text-align:right;"|2:00 PM||||
|-
| style="text-align:right;"|4:00 PM||||
|-
| style="text-align:right;"|6:00 PM||
|rowspan=6|Normal night from 6 PM to 6 AM
|-
| style="text-align:right;"|8:00 PM||
|-
| style="text-align:right;"|10:00 PM
|rowspan=4|Sleep
|-
| rowspan=12|Thursday||style="text-align:right;"|12:00 AM
|-
| style="text-align:right;"|2:00 AM
|-
| style="text-align:right;"|4:00 AM
|-
| style="text-align:right;"|6:00 AM||||
|-
| style="text-align:right;"|8:00 AM||||
|-
| style="text-align:right;"|10:00 AM||||
|-
| style="text-align:right;"|12:00 PM||||
|-
| style="text-align:right;"|2:00 PM||||
|-
| style="text-align:right;"|4:00 PM||||
|-
| style="text-align:right;"|6:00 PM||
|rowspan=6|Normal night from 6 PM to 6 AM
|-
| style="text-align:right;"|8:00 PM||
|-
| style="text-align:right;"|10:00 PM||
|-
| rowspan=12|Friday||style="text-align:right;"|12:00 AM||
|-
| style="text-align:right;"|2:00 AM
|rowspan=4|Sleep
|-
| style="text-align:right;"|4:00 AM
|-
| style="text-align:right;"|6:00 AM||
|-
| style="text-align:right;"|8:00 AM||
|-
| style="text-align:right;"|10:00 AM||||
|-
| style="text-align:right;"|12:00 PM||||
|-
| style="text-align:right;"|2:00 PM||||
|-
| style="text-align:right;"|4:00 PM||||
|-
| style="text-align:right;"|6:00 PM||
|rowspan=6|Normal night from 6 PM to 6 AM
|-
| style="text-align:right;"|8:00 PM||
|-
| style="text-align:right;"|10:00 PM||
|-
| rowspan=12|Saturday||style="text-align:right;"|12:00 AM||
|-
| style="text-align:right;"|2:00 AM||
|-
| style="text-align:right;"|4:00 AM||
|-
| style="text-align:right;"|6:00 AM
|rowspan=4|Sleep
|
|-
| style="text-align:right;"|8:00 AM||
|-
| style="text-align:right;"|10:00 AM||
|-
| style="text-align:right;"|12:00 PM||
|-
| style="text-align:right;"|2:00 PM||||
|-
| style="text-align:right;"|4:00 PM||||
|-
| style="text-align:right;"|6:00 PM||
|rowspan=3|Normal night from 6 PM to 6 AM
|-
| style="text-align:right;"|8:00 PM||
|-
| style="text-align:right;"|10:00 PM||
|}

==Transcript==
:[Above the panels of the main comic, there is a ruler-like time line diagram that shows the hours in a week. It has 6 black sections labeled "bed" in white text, at the top and 7 black sections labeled "night" in white text, at the bottom (the first and last sections are split in two as it goes from the end of the week to the start of the (next) week. So there are 8 night sections, but they only cover 7 times 12 hours). The night sections always go from 6PM to 6AM. But the bed sections are only 8 hours long and they only stay fully over the night sections two times, and two times they are not above the night sections at all. Above the ruler, the bed times are shown. These labels are over the relevant ticks on the ruler. The ruler has small ticks for every two hours, longer ticks at noon, and a line that goes all the way through the ruler dividing each day. The ruler begins on midnight as Sunday starts and ends as Saturday finishes at midnight. Below the ruler each day are labels with the three-letter abbreviations in a much larger font. Here below the rulers, text is transcribed with the day first, then night or bed according to which comes first, and the time interval for bed given after each bed. The first and last night will only be a partial word and only the first time will there be a (ni)ght to start.]
:<big>Sun</big>
:ght
:Bed
:10AM 6PM
:Night

:<big>Mon</big>
:Bed
:2PM 10PM
:Night

:<big>Tue</big>
:Bed
:6PM 2AM
:Night

:<big>Wed</big>
:Night
:Bed
:10PM 6AM

:<big>Thu</big>
:Night

:<big>Fri</big>
:Bed
:2AM 10AM
:Night

:<big>Sat</big>
:Bed
:6AM 2PM
:Nig

:[Below the ruler are five panels. In the first, two Cueball-like guys are talking together. Cueball is addressing his friend with one hand raised.]
:Cueball: You have trouble sleeping right?
:Friend: Only when your mom is over.

:[Cueball is now standing next to a an easel with a large version of the chart shown above the panels. Cueball is pointing to the chart while his friend is looking at it.]
:Cueball: Since your work is flexible-
:Friend: -Like your mom-
:Cueball: -you should try the 28-hour day - 20 awake, 8 asleep (or 19/9 if you prefer).
:Friend: I prefer your mom.

:[Cueball moves forward toward his friend, with the chart behind him. He holds both hands, held together, up in front of him. The easel with the chart can now be seen to have three legs, as opposed to only two shown in the previous panel.]
:Cueball: It synchs up with the week - you spend weekdays awake normally, then on weekends you can go out all night.
:Friend: Just like your mom.

:[In a frameless panel, only Cueball is shown from the torso up. He gestures with both arms raised on each side of him.]
:Cueball: It means four extra hours daily. You can stay up until you're exhausted every day and then spend a full 9 hours asleep each night!

:[Back to both again, but without the chart. Cueball leans toward his friend as his friend lifts a hand to his chin.]
:Friend: But how much time can I spend doing your mom?
:Cueball: You? I'm guessing three or four minutes, tops.
:Friend: ...Well played.

{{comic discussion}}

[[Category:Comics featuring Cueball]]
[[Category:Multiple Cueballs]]
[[Category:Your Mom]]
[[Category:Sex]]
[[Category:Time]]
[[Category:Timelines]]
[[Category:Charts]]

2940: Modes of Transportation

2024-06-03T09:31:17Z

172.70.85.6: /* Explanation */

{{comic
| number = 2940
| date = May 31, 2024
| title = Modes of Transportation
| image = modes_of_transportation_2x.png
| imagesize = 510x518px
| noexpand = true
| titletext = My bold criticism might anger the hot air balloon people, which would be a real concern if any of them lived along a very narrow line directly upwind of me.
}}

==Explanation==
{{incomplete|Created by a Transportationally convenient but insidiously dangerous robotic car - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

Randall's chart compares different modes of transportation by how convenient and dangerous they are. At the top-left (high in convenience and low in danger) are airliners and trains, as these are both fast-moving but heavy vehicles on which many millions of dollars have been spent to make them safer. In the top-right, motorcycles are at the same convenience level, but are rated much more dangerous, since they are easy to lose control of at high speeds, and careless drivers (of cars) can easily hit a motorcycle and cause extreme harm. Things like unicycles (bottom-left) are considered much lower on the convenience scale, being not very fast or easy ways to travel, but relatively safe, while towards the centre, skis are apparently moderately convenient and moderately dangerous, since they are relatively easy to fall on if going fast downhill. Way out on their own in the bottom-right, hot air balloons appear to be unique in being rated least on convenience and highest on danger.

Because a hot air balloon is rated so poorly, if an optimization algorithm considers it the optimal mode of transportation, it must be the result of a sign error (e.g. having a minus sign where a plus sign is supposed to be, or vice versa), making the algorithm optimize for the opposite result by mistake. Presumably, modes of transportation similar to hot air balloons (like zeppelins and blimps) are left off the chart to increase the gap for comedic effect.

The title text makes a joke that if an angry hot air balloon enthusiast disagrees with the ranking, they will have a difficult time getting to Randall's house with their preferred mode of transportation, because they are limited to travelling in the direction of the wind. In reality, hot air balloons have some freedom to choose their direction of travel, since by controlling their altitude they can access different wind directions at different heights. Randall should, therefore, be concerned about hot air balloonists who live within a wedge spanned by the various wind directions accessible on a given day. In principle, if the weather conditions are favorable, this could cover every direction from Randall's house. The phrase "hot air balloon people" is reminiscent of "autogyro people" from the title text of [[1972: Autogyros]].

Curiously, the comic includes most common forms of transport, and a number of less common ones, but omits examples such as buses (a mass transit solution arguably more convenient than trains). It is not clear if this is an error, or a deliberate choice to maintain the comic's layout and presentation.

This is the second comic in a row to feature an algorithm.

{| class="wikitable sortable"
|-
! Transportation !! Description !! Convenience !! Danger !! Zone
|-
|{{w|Train}}s
|Mass transit on rails Very convenient ''if'' scheduled services along established routes are well suited for your journey. Many people can make journeys in complete safely on dedicated tracks (Incidents can affect many people at once, but are comparatively rare.)
|data-sort-value=""|
|data-sort-value=""|
|Practicality
|-
|{{w|Airliner}}s
|Mass transit aircraft As long as there are convenient airports, and operators. Air travel is ''very'' safe, accounting for the number of miles traveled and passengers carried. (Accidents can be catastrophic both to the passengers/crew and potentially anybody on the ground, however.)
|data-sort-value=""|
|data-sort-value=""|
|Practicality
|-
|{{w|Car}}s
|Motorised road vehicle Most common method of long distance travel used to get anywhere from a mile to 200 miles. It is mostly safe (for those ''inside'' the car), since many safety features have gradually been introduced, either as the result of regulation, or as selling features.
|data-sort-value=""|
|data-sort-value=""|
|Practicality
|-
|Scooters
|Either: 
*{{w|Kick scooter}} - ...
*{{w|Motorized scooter|Engine-powered scooter}} - ...
*{{w|Scooter (motorcycle)|Low powered motorbike/moped}} - ...
|data-sort-value=""|
|data-sort-value=""|
|Practicality
|-
|{{w|Bicycle}}s
|Human-powered (or {{w|Electric bicycle|mostly so}}) two-wheeled road vehicle ...
|data-sort-value=""|
|data-sort-value=""|
|Practicality
|-
|{{w|Boat}}s
|Watercraft of various types ...
|data-sort-value=""|
|data-sort-value=""|
|Practicality
|-
|{{w|Walking}}
|Personal bipedal ambulation 
|data-sort-value=""|
|data-sort-value=""|
|Practicality
|-
|{{w|Motorcycle}}s
|...
|data-sort-value=""|
|data-sort-value=""|
|Speciality/Recreational
|-
|{{w|Helicopter}}s
|...
|data-sort-value=""|
|data-sort-value=""|
|Speciality/Recreational
|-
|{{w|Light aircraft}}
|In the United States, the general category of [https://www.faa.gov/aircraft/air_cert/design_approvals/small_airplanes/categories small aircraft] covers a variety of aircraft certified to weigh 19,000 pounds (8618 kg) or less at takeoff. Maximum allowed weight varies by specific category.
|data-sort-value=""|
|data-sort-value=""|
|Speciality/Recreational
|-
|{{w|Go-kart}}s
|...
|data-sort-value=""|
|data-sort-value=""|
|Speciality/Recreational
|-
|{{w|Skateboard}}s
|...
|data-sort-value=""|
|data-sort-value=""|
|Speciality/Recreational
|-
|{{w|Inline skates|Rollerblades}}
|...
|data-sort-value=""|
|data-sort-value=""|
|Speciality/Recreational
|-
|{{w|Ski}}s
|...
|data-sort-value=""|
|data-sort-value=""|
|Speciality/Recreational
|-
|{{w|Unicycle}}s
|...
|data-sort-value=""|
|data-sort-value=""|
|Speciality/Recreational
|-
|{{w|Sled}}s
|...
|data-sort-value=""|
|data-sort-value=""|
|Speciality/Recreational
|-
|{{w|Bumper Cars}}
|...
|data-sort-value=""|
|data-sort-value=""|
|Speciality/Recreational
|-
|{{w|Hot Air Balloon}}s
|...
|data-sort-value=""|
|data-sort-value=""|
|?????
|}

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

:[A chart is shown, where the Y axis is labeled "Convenient for travel" and has an arrow pointing up and the X axis is labeled "Dangerous" and has an arrow pointing right.]
:[The following modes are shown in the "Zone of practicality" (a large irregular area fitting in to the top left corner of the chart), highlighted with a gray background, starting with the first few bunched at highest convenience, :]
:Trains [very convenient, very safe]
:Airliners
:Cars
:Scooters [the most dangerous of this set, at medium-low danger]
:Bicycles
:Boats [medium-high convenience, a slight amount of danger]
:Walking [the least convienient, at roughly half, and lowest danger of this set]
:[The following modes are shown in the "Zone of specialty and recreational vehicles" (a large irregular swathe from the top right to the bottom left, not quite touching the prior zone), highlighted with a gray background, the nodes spread in rough order from high convenience/danger to low convenience/danger:]
:Motorcycles [highly convenient, nearly maximum danger]
:Helicopters [not quite fully convenient, most danger]
:Light aircraft
:Go karts
:Skateboards
:Rollerblades
:Skis
:Unicycles
:Sleds
:Bumper cars [lowest convenience and lowest danger item]
:[The following is labeled "?????" (in the bottom right corner), and has a gray background all to itself in a small blob notably distant from the nearest other group:]
:Hot air balloons [placed as almost the least convenient and most dangerous, of all labels]

:[Caption below the panel:]
:Hot air balloons are the optimal mode of transportation, if your optimization algorithm has a sign error.

{{comic discussion}}

[[Category:Charts]]

790: Control

2024-05-31T13:23:27Z

172.70.85.6: /* Explanation */ Depends upon protocol. These may even not be the study-administering folks, but the ones dealing with the aftercare.

{{comic
| number = 790
| date = September 8, 2010
| title = Control
| image = control.png
| titletext = Which, at one point, led to a study showing that LSD produces no more hallucinations than a placebo.
}}

==Explanation==
This is another comic in the [[:Category:My Hobby|My Hobby series]]. In a product experiment, two groups of people are given a certain pill or lotion. Some people are given the product to be tested, while others (the control group) are given a placebo; nobody is told which group they belong to. The control group acts as a norm for comparison against the others.

Randall has messed with this process by giving LSD ({{w|lysergic acid diethylamide}}) to the control group. LSD is a drug that causes hallucinations and distortions in the perception of time and space. [[Megan]], apparently a control, is experiencing spiders in her hallucinations. Since the control group is supposed to reflect what "normally" happens, this is indeed very confusing to the scientists. While hallucinating in the comic Megan is drawn as if she has six arms indicating that she's waving her arms. Though this also makes her look (together with her lower limbs) as if she has eight 'legs', in the manner of an actual spider.

The scientists are confused. This may mean that, in the light of the unusual adverse events, they have executed the option of unblinding the study. This implies that the trial has (or is being) ended, as not being double-blinded itself impacts the veracity of a continuing study. In a properly double-blinded study, the scientists would not know Cueball or [[Megan]] was the control and would only dutifully record their observations. However, it may be equally confusing even if they don't yet know which cohorts either participant are members of (for all they know, these two are from the same one), as the treatment may or may not be creating hallucinations even as the non-treatment may or may not seem to clear up rashes.

The title text suggests that, in a different study, this substitution was performed when the product being tested was itself LSD. This led to the conclusion that LSD is no more likely to cause hallucinations than the 'placebo', implying that LSD is not a significant hallucinogen. We can only hope they were able to redo the test, as in layman's terms "Nonsense MUST be wrong". Randall could also have only sneaked placebo in as the 'LSD' element of the study, to get the same comparative effect, though (if checked) the difference between the ''whole'' cohorts, from each modified type of study, would be striking.

==Transcript==
:[Caption above the frame:]
:My Hobby:

:[Cueball looks down at his arm calmly, while next to him Megan is violently flailing around in terror. In the foreground a Cueball-like guy stands next to Ponytail who is holding a clipboard. They look on in puzzlement.]
:Cueball: My rash seems to have shrunk by about 20% today.
:Megan: OH GOD SPIDERS
:Cueball-like guy: ? ?
:Ponytail: ?

:[Caption below the frame:]
:Sneaking into experiments and giving LSD to the control group.

{{comic discussion}}

[[Category:My Hobby]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Ponytail]]
[[Category:Multiple Cueballs]]
[[Category:Spiders]]
[[Category:Scientific research]]

2926: Doppler Effect

2024-04-29T21:58:33Z

172.70.85.6: /* Explanation */ Why sirens are ideal analogies. (You might be able to bear the same in a thumping bass, but couldn't entirely rule out that the 'tune' hadn't shited its base(/bass!) key...)

{{comic
| number = 2926
| date = April 29, 2024
| title = Doppler Effect
| image = doppler_effect_2x.png
| imagesize = 671x317px
| noexpand = true
| titletext = The Doppler effect is a mysterious wavelength-shifting phenomenon which seems to primarily affect sirens, which is why the 🚨 emoji is red.
}}

==Explanation==
{{incomplete|Created by an ALARMED BOT THAT GOES NYOOOOM - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

[[Miss Lenhart]] is teaching a class about the concept of {{w|redshift}} and using the {{w|Doppler effect}} as a demonstration. The comparison begins as relevant, but then quickly becomes extraneous when she brings up the "BUTTON THAT MAKES IT GO ''PYEEW! PYEEW!''". In fact, it seems she cares more about her special interest in various emergency vehicle sirens than about astronomy, the field in which she teaches, similar to [[1519: Venus]].

In the second and third panels, Miss Lenhart talks about the strange noise sirens (and cars) make when the pass you. The usual explanation of Doppler effect is that the source of the sound waves is moving. Consider a sound being generated at a frequency of 1000 cycles per second ({{w|Hertz|Hz}}); each wave will propagate at a fixed speed in the air, the speed of sound. The car generates peak A, which begins moving away at the speed of sound, and 1/1000th of a second later, generates peak B, which also begins moving away at the speed of sound. In that 1/1000th of a second between peaks being generated, the car has traveled slightly forward, so peak B is produced slightly farther along the car's direction of travel than the previous peak. For an observer in front of the car, because peak B was generated a bit closer to the observer, they would measure (hear) a shorter wavelength (higher pitch) than if the peaks were generated from a stationary car. Similarly, for an observer behind the car, because peak B was generated a bit further away, they would hear a lower pitch. However, Miss Lenhart doesn't make this usual explanation and instead starts talking about how cool emergency sirens are.

Redshift is the same concept applied to wavelength of light and stellar objects. Red has longer wavelength than blue, and stars gets red when they move away from us and blue when they move towards us. We usually talk about redshift and not blueshift because while stars in our galaxy can move in any direction relative to us, most other galaxies are moving away from us, and in fact are moving quicker the farther away they are due to universe expansion. Note that unlike the usual explanation of redshift for sirens, a major component of the redshift of light from distant galaxies is due to the expansion of space. This effect is not an important component of the Doppler shift for sirens. Redshift has been mentioned multiple times before, such as in [[2764: Cosmological Nostalgia Content]] and [[2853: Redshift]].

''Still unexplained: What is the "button" that sometimes makes the noise go "pew pew"? Gun triggers?''

The title text explains that the Doppler effect particularly affects sirens. This isn't actually true,{{cn}} but it may seem like it because sirens tend to employ a recognisable tone (or a given sequence of them), which most people who aren't {{w|Amusia|totally tone deaf}} would have experienced a shift of from a passing vehicle's siren (whereas something like engine noise could change according to differences of speed and the gearbox), as per the initital analogy in Miss Lenhart's lecture. Then it claims that the emoji for sirens is red because they're associated with redshift. Actually, the emoji is a picture of the rotating light on top of emergency vehicles; these tend to be used in conjunction with sirens, and they're red because this color typically signifies danger or warning.

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

:[Miss Lenhart is pointing with a stick to a whiteboard with various scientific drawings and words, including but not only a graph.]
:Miss Lenhart: The more distant a galaxy is, the redder its light.
:Miss Lenhart: Why? Well, that's an interesting question.

:[Zoom in on Miss Lenhart.]
:Miss Lenhart: Ever notice how, when a siren is approaching, it sounds like '''''Bweeeeeeeeee...'''''

:[Zoom in on Miss Lenhart with her arms raised.]
:Miss Lenhart: ...but then it zooms past and goes '''''Nyeeeeooooowww?'''''
:Miss Lenhart: And sometimes they hit a button that makes it go '''''Pyeew! Pyeew!''''' really loud?

:[Miss Lenhart with her finger raised is standing in front of the whiteboard and holding the stick down.]
:Miss Lenhart: And in Europe they go '''''Ooooeeeeooooeeee...'''''
:Off-panel voice: So '''''why''''' are galaxies red?
:Miss Lenhart: Oh, no idea.
:Miss Lenhart: Anyway, another siren I like is...

{{comic discussion}}

[[Category:Comics featuring Miss Lenhart]]
[[Category:Physics]]
[[Category:Astronomy]]
[[Category:Emoji]]

2920: Survey Marker

2024-04-16T07:29:49Z

172.70.85.6: /* Explanation */

{{comic
| number = 2920
| date = April 15, 2024
| title = Survey Marker
| image = survey_marker_2x.png
| imagesize = 740x272px
| noexpand = true
| titletext = Fun fact: The standard North American NAD83 coordinate system is misaligned from the actual Earth, off-center by about 7 feet. Someone knows where I am, and I'm in the wrong place.
}}

==Explanation==
{{incomplete|Created by a GUIDED MISSILE THAT MISSED THE TARGET DUE TO COORDINATE DRIFT - Please change this comment when editing this page. Do NOT delete this tag too soon.}}
When they update the database, Cueball's position changes to compensate.

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

[Marker on the floor] U.S. Geological survey bench mark
Eleavation above sea 447 feet

Cueball [standing on the marker]: I love finding these survey markers. It's somehow reassuring.
I like that someone, somewhere, knows where this spot is.
If I stand on it, they know where I am.

Ponytail: But the NAD83 and NAVD88 datums are getting replaced soon. That marker's coordinates could be shift by like 5 feet.
Oh look, it jus got updated

Cueball [elevating]: Hey! Put me back!

{{comic discussion}}