explain xkcd - User contributions [en]

Talk:2973: Ferris Wheels

2024-08-18T21:06:41Z

172.71.146.49:

Where is the Cueball shouting "wheee!!"? [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 19:59, 16 August 2024 (UTC)
: Probably dead if he was on the 3rd wheel. [[Special:Contributions/172.70.46.90|172.70.46.90]] 12:18, 17 August 2024 (UTC)

In the transcript I described how the cars are hanging, but I'm worried I've gone too far from transcript to explanation. Hopefully someone can improve it. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 20:02, 16 August 2024 (UTC)
:No direct explanation and links should be given in the transcript. I have removed it. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 19:31, 17 August 2024 (UTC)

There's no category for "X fired me because" comics. There probably should be. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 20:06, 16 August 2024 (UTC)
:If you can list some more than this and the one already mentioned [[2935: Ocean Loop]] it might be relevant. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 19:31, 17 August 2024 (UTC)
::I could not help my self and searched and found these:
:::[[1428: Move Fast and Break Things]]
:::[[1815: Flag]]
:::[[2219: Earthquake Early Warnings]] (title text)
:::[[2728: Lane Change Highway]]
::I also remembered this one [[2447: Hammer Incident]], but it does not say he got fired, although I'm sure he did.
::Same might happen to Steve in [[1532: New Horizons]] but again not mention the fired word.
::Here is one that got fired but not like that [[649: Static]].
::Fired not mentioned but implied here: [[1852: Election Map]].
::Same with this one: [[1985: Meteorologist]]
:::I'm not sure if all comics someone is fired for incompetence should go in such a category, or only those where it is directly mentioned, basically as first suggested? So until someone chips in I'm not going to create the category. For what should the name be and which of these comics should be included? --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 19:58, 17 August 2024 (UTC)

I once attached the motor of a Lego ferris wheel directly to its axis instead of the beginning of the gearing system. Not only did all the cabins fly across the room, the entire thing dismantled itself. Worth it! [[User:Fabian42|Fabian42]] ([[User talk:Fabian42|talk]]) 01:03, 17 August 2024 (UTC)

== Just HOW fast? ==

I was vaguely surprised to see nobody had done the math yet. So here it goes -- someone more confident in editing the main entry can feel free to adapt this if you think it's interesting enough (I doubt anyone would want to read the math as I wrote it). But first, someone please check my work. :)

I opened the comic in a pixel-level photo editor and took some quick measurements. The wheel on the left seems to be approximately 160 pixels wide, whiile the inner hub is about 14 pixels high.

So the gear ratio is 160:14 or about 11.04 Just for simplification, let's call it a 10x ratio.

The [https://en.wikipedia.org/wiki/Ferris_wheel#The_original_Ferris_Wheel original Ferris Wheel] took about 20 minutes to load and unload passengers, then ran for 9 uninterrupted minutes for another, full, rotation. So again, let's round up and say the wheel on the left takes about 10 minutes to go around once.

The middle wheel, then, would take a minute. And the last one, a tenth of a minute, or 6 seconds.

The original wheel (again) was about 265 feet【80.77 m】 across, or a circumference of 832 feet【253.59 m】. So if these wheels are the same size (why not?), any car on the right-most wheel would move about 832 feet【253.59 m】 in 6 seconds, or 138 feet【42.06 m】 per second, which is about 94 miles【151.28 km】 per hour (151 kilometers per hour).

I can see why he was fired.

Taking the reverse: The rightmost wheel would take about 10 minutes for a rotation, the middle wheel, 100 minutes (1:40) and the left most, 1000 minutes (16 hours and 40 minutes).

Actually, if you move slow enough that the right wheel can load and unload (let's say 20 minutes, just like the original wheel), it'd take over a day to load the left wheel.

@DarthNull@infosec.exchange [[Special:Contributions/172.70.175.87|172.70.175.87]] 20:58, 16 August 2024 (UTC)

This Amusement Ride manufacturer has a helpful diagram of rotational speed on their website: https://www.sinorides.com/everything-you-need-to-know-about-ferris-wheels/#q11
The example wheel happens to have 18 gondolas, just like Randall's and appears to be roughly the same scale. The sample values they provide are a linear speed of 4 m/s at the edge of the wheel and a rotational speed of just under 3 revolutions per minute. My best guess at the gearing ratio of Randall's belt driven wheels is 10:1, so if the left wheel is being driven at normal speeds, the center wheel would be 40 m/s or 30 rpm and the left wheel would be 400 m/s or 300 rpm. This exceeds the square root of the specific strength of standard steel, so we'll need to hope that the right most Ferris wheel is made of a particularly strong alloy. [[Special:Contributions/172.69.71.97|172.69.71.97]] 21:19, 16 August 2024 (UTC)

: Ah, well, I started down my own road for calculations, based upon the assumption that they were 75 feet【22.86 m】 diameter (from the height of the figures, assuming that the ones I actually checked definitively up to 6ft【1.83 m】, give or take, although pixel-counts upon antialiased graphics can be quite inaccurate the fewer 'apparent' pixels there are). As a truck-portable/mounted fairground-style ride, it's probably quite a bit smaller than the 'original Ferris wheel' and many of those 'permanent' wheels (London Eye, theme park rides, etc) that are built specifically to be architectual 'statements'/tourist-magnets. I'm thinking more the kind that you'd see in Grease (though that one's 55-foot【16.76 m】, apparently) or the one that 'Night Monkey' had to deal with in Spiderman: Far From Home. I also looked up [https://www.giantwheel.co.uk/35m-vision-ferris-wheel-hire/ actual specs] (that's 35m, ~105ft【32 m】 and 0.5rpm, so not too far off my initial assumptions). There also was a rather larger 60-metre (197 ft) {{w|Wheel of Sheffield|semi-permanent}} transportable version with 13 minute continuous 'ride', but that'd be completely out of scale to those depicted.
: If there are any actual 'carnies' out there who know what kind of thing actually gets used at County Fairs in the US, that might help. (Here in the UK there's currently a Fun Fair about a quarter of a mile from my house, at the moment - though I'm not there at the moment, but they have no 'big wheels' of that kind, only the more energetic types that ''do'' fling their riders around, like the "Terrifying Claw" and various other heavy duty hanging and/or spinning-seat rides.) ((Slightly ninjaed, now, by the above contribution.))) [[Special:Contributions/162.158.33.197|162.158.33.197]] 21:37, 16 August 2024 (UTC)

I can't help but think of this as Randall wanting to make an upscaled version of [https://www.youtube.com/watch?v=QrkiJZKJfpY Steve Mould's Spintronics video] from a year ago... [[Special:Contributions/172.68.50.126|172.68.50.126]] 21:54, 16 August 2024 (UTC)

Given that air resistance increases exponentially with air speed, this setup would actually act as its own speed regulator, with the main factor being the torque of the power source. Which wheel is powered would not matter much [[Special:Contributions/172.71.118.167|172.71.118.167]] 22:05, 16 August 2024 (UTC)
:Drag is quadratic, not exponential. You aren't trying to quantum tunnel through the air until you reach relativistic velocities, and then length contraction means going faster decreases drag, which doesn't help regulate speed at all. [[Special:Contributions/172.71.146.49|172.71.146.49]] 21:06, 18 August 2024 (UTC)

If you powered the middle one, you'd end up with one moderately exciting ride, one normal ride and one really long ride, which would be highly impractical, but not overly dangerous (depending on the structural strength of the fast wheel). [[Special:Contributions/172.71.142.88|172.71.142.88]] 23:08, 16 August 2024 (UTC)

The ratio is listed as 12.5:1, but then the calculations are done using a ration of 20:1. The 12.5 seems to be more accurate, given the drawing, but in the comments here, someone else measured the pixel ratio as 11.04. I think 10 or 12.5 would be fine, but it should be consistent. Knowing the ratio ahead of time would also make the rotation calculations easier to explain. We should probably use the pixel technique to estimate the diameter too. I don’t have access to measuring tools right now, but it’s about 20 times the height of the tallest person, so roughly 120’【36.58 m】. --[[Special:Contributions/172.69.34.87|172.69.34.87]] 00:32, 17 August 2024 (UTC)

:I am surprised that everyone seems to be doing calculations by counting how wide circes are in pixels and nobody is doing calculations based upon the angle of the (buckets? seats? cars?). What is the fastest speed for the left wheel that leaves the seats hanging down to the precision of the image? What is the slowest speed for the right wheel that leaves the seats splayed out like that? (let's ignore that one seat...) What speed for the center wheel would account for the angles of the seats? Are the answers consistant with the previous calculations based on ratios?

:Also, real ferris wheels stop and start so new passengers can get on. Not only would that change the rim speed vs RPM figures but it would make it hard to unload the corpses and load fresh victims on to the right wheel. :( Source: My summer working as a carny. I was on the tilt-o-wheel but the ferris wheel was right next to it. [[Special:Contributions/172.69.34.126|172.69.34.126]] 13:53, 17 August 2024 (UTC)

;Are the transcript eds going to go into the speeds depicted?

Should the transcript involve the diameter ratios when explaining the speed depiction gray lines? [[Special:Contributions/172.70.211.83|172.70.211.83]] 23:06, 16 August 2024 (UTC)
:Such analysis is going towards the speculative. Perhaps we can say that the wheels are <so many> people-heights high, but that doesn't give us any actual definitive speeds to go with the lines, with no actual given first-wheel speed (two minutes a spin? three minutes per spin? thirteen minute 'trips'?). It might be reasonable to mention the hub-to-rim ratio details, but the speed-lines just need to be subjectively described. [[Special:Contributions/172.70.58.3|172.70.58.3]] 23:24, 16 August 2024 (UTC)
::No explanation and links should be given in the transcript. I have removed it. --[[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 19:30, 17 August 2024 (UTC)

By my measurement, wheel1 (outer) is 203 pixels from left edge (at the belt 'grip surface' radius, i.e. as far in as the outer-black-line is before it becomes 'background white' wheel rim), wheel2 hub is 16 pixels (likewise), wheel2 outer is also 203, wheel3 hub is 15 (debatable). Wheel3 (outer) is 202, but the relevence here is more that it's 238 pixels from gondola-bottom to gondola-bottom. (Wheel1 hub is 15, but doesn't even have that relevence.) Can't measure the verticals of the outers, because of the supporting structure, but the the vertical hub measurements agree exactly with the horizontal spreads (which at least means that Randall can draw circles reasonable accurately). 203/16=12.6875, 203/15=13.533... Maybe I should be looking a pixel further out, which gives 204/17=12 or 204/16=12.75. 1:12 (and, by extension 1:144 for the both) seems nicely numbered slightly better and more symbolically than 1:12.5 (or 2:25) and its square (4:625) might be, whatever choice of measurements came up with that. - The tallest figures are 10 pixels high (maybe you could stretch some to 11, depending upon where you 'zero' the ground-line), meaning 20(and-a-bit) figure-heights (some are smaller, single-pixels could be variations/stereotypically slightly smaller females, but I think there are clear child/adolescent figures as part of/all of some groupings, whether by deliberate artistic design or just a matter of how the quick squiggles turned out). 120ft (6 foot figures) is not really far off the 35m mentioned above (with the wrong feetwise equivalent!) as an actual wheel of 0.5rpm. So 6rpm and then 72rpm. 22m radius (taking a decent round figure, whilst metrifying the extended width of the) at that speed seems to be 128g (if I've not messed up), a nice 'round' figure to a nerd. But that'd be at the base of the gondalas, and decrease (bit by bit) if you move even a pixel 'inward' from the that (and a 128g centrifuge isn't going to have a paper-thin floor!)... Plenty of open questions/rooms for error in all that, so not at all worth giving as an Explanation calculation, nor Transcript detail, but it's where I personally ended up. [[Special:Contributions/172.68.205.134|172.68.205.134]] 00:11, 17 August 2024 (UTC)

Ferb, I know how we're gonna execute war criminals today! [[Special:Contributions/141.101.99.88|141.101.99.88]] 10:52, 17 August 2024 (UTC)
: Hey, where's Perry's corpse? [[User:B_for_brain|B for brain]] ([[User_talk:B_for_brain|talk]]) ([https://www.youtube.com/channel/UCg4bo-hj-mDyOOUp_Yp0pug youtube channel] [https://bforbrain.weebly.com/ wobsite (supposed to be a blag)]) 17:46, 17 August 2024 (UTC)

2972: Helium Synthesis

2024-08-15T09:12:09Z

172.71.146.49: /* Explanation */ another related comic

{{comic
| number = 2972
| date = August 14, 2024
| title = Helium Synthesis
| image = helium_synthesis_2x.png
| imagesize = 740x312px
| noexpand = true
| titletext = Our lawyers were worried because it turns out the company inherits its debt from the parent universe, but luckily cosmic inflation reduced it to nearly zero.
}}

==Explanation==
{{incomplete|Created by a BIG BANG NUCLEOSYNTHESIZER - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

This comic explores the challenges of obtaining {{w|helium}}. [[Hairy]] is leading a meeting with [[Megan]], [[Cueball]], and [[Hairbun]], who are discussing the recurring problem of {{w|helium shortage}}s, a real-world issue due to helium's limited availability on Earth. Helium is a non-renewable resource extracted from {{w|natural gas}} deposits, and its scarcity can affect industries that rely on it, such as medical imaging, semiconductor manufacturing, scientific research, and party balloon supplies.[https://www.marketplace.org/2023/01/19/heliums-been-rising-in-price-and-its-bringing-businesses-down/] (See also [[2766: Helium Reserve]].)

Hairbun suggests investigating the origin of helium. Cueball's research reveals that most helium in the universe came from {{w|Big Bang nucleosynthesis}}, the process that occurred shortly after the {{w|Big Bang}}, when the first elements were formed. (However, 99% of the helium here on Earth has been produced from the {{w|radioactive decay}} of {{w|uranium-238}} and {{w|thorium-232}} — which in turn came from {{w|r-process}} {{w|Supernova nucleosynthesis|nucleosynthesis}} inside {{w|supernova}}e, like [[2826: Gold]] did — into {{w|alpha particles}} equivalent to ionized helium, with only the remaining one percent originating from the Big Bang.)

Hairy assigns the team to figure out how to recreate Big Bang nucleosynthesis, which is not actually possible for a contemporary business organization.{{cn}} Nonetheless, the team builds a machine capable of it. While one might hope they would realize activating it would obliterate them along with at least all the closest galaxies, ironically that disadvantage seems to escape their attention in the tightly focused drive towards their ill-fated mission.

The final panels show the creation of a second Big Bang, and the following 14 billion years into the future, culminating with the same characters in the same meeting, presumably having arisen from an identical series of post-Big Bang events as had occurred in the original universe, only to arrive at the same predicament: helium shortages are still a problem, and they still need a reliable source. That such an extreme solution didn't actually solve the problem shows the impracticality of their plan, suggesting that some problems are too complex or vast to solve through brainstorming of corporate efforts.

The title text is a wordplay on the concept of {{w|cosmic inflation}}, a theory in cosmology that describes the rapid expansion of the universe just after the Big Bang. The joke imagines the company as having inherited a debt from the parent universe, perhaps due to the expense of creating a second Big Bang. However, thanks to cosmic inflation which dramatically expanded the universe, the debt was diluted (perhaps across the vastness of space), reducing it to almost nothing—much like how {{w|monetary inflation}} reduces the relative cost of debt in fiscal terms. (See also [[2688: Bubble Universes]].)

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
:[Hairy sits at the head of a conference table, with Cueball and Megan also at the table.]
:Hairy: These helium shortages every few years are such a pain.
:Hairy: Our company needs a reliable source of helium.

:[The same situation, but now Hairbun is also seen at the table to Cueball's left. Cueball holds a cellphone in his left hand, which Megan looks at.]
:Hairbun: Where does helium come from, anyway?
:Cueball: Hmm, apparently most of it is from "big bang nucleosynthesis"?
:Hairy: Well, let's figure out how to do that.

:[Hairy, Megan and Hairbun are working on a large machine labeled "Big Bang Nucleosynthesis," with Megan holding its control device.]

:[Two panels depict another Big Bang, followed by various stages of cosmic development, including galaxies and planets forming, shown in white on a black background.]

:[The scene returns to the same conference room setup as before, with the characters in the same positions. Text at the top reads: "14 Billion Years Later."]
:Hairy: These helium shortages every few years are such a pain.
:Hairy: Our company needs a reliable source of helium.

{{comic discussion}}
[[Category:Comics featuring Hairy]]
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Comics featuring Hairbun]]
[[Category:Cosmology]]
[[Category:Physics]]

Talk:2971: Celestial Event

2024-08-13T06:00:07Z

172.71.146.49:

Unfortunately, this calculation doesn't account for the eventual end of total solar eclipses due to the tidal recession of the moon. [[Special:Contributions/172.69.246.142|172.69.246.142]] 05:31, 13 August 2024 (UTC)

-This is a great comment! Very much like something Randall would have written for title text. [[Special:Contributions/172.71.146.49|172.71.146.49]] 05:58, 13 August 2024 (UTC)

Talk:2971: Celestial Event

2024-08-13T05:58:22Z

172.71.146.49:

Unfortunately, this calculation doesn't account for the eventual end of total solar eclipses due to the tidal recession of the moon. [[Special:Contributions/172.69.246.142|172.69.246.142]] 05:31, 13 August 2024 (UTC)
This is a great comment! Very much like something Randall would have written for title text. [[Special:Contributions/172.71.146.49|172.71.146.49]] 05:58, 13 August 2024 (UTC)

2783: Ruling Out

2023-05-31T18:22:53Z

172.71.146.49: /* Explanation */

{{comic
| number = 2783
| date = May 31, 2023
| title = Ruling Out
| image = ruling_out_2x.png
| imagesize = 295x396px
| noexpand = true
| titletext = We were able to replicate and confirm prior authors' detection of a moon orbiting the Earth with high confidence.
}}

==Explanation==
{{incomplete|Created by a TECTONICALLY-ACTIVE BOT WITH SUBSURFACE OCEANS - Please change this comment when editing this page. Do NOT delete this tag too soon.}}

Cueball lists a number of obviously{{fact}} impossible objects.

* The Earth is not a star{{fact}}, hence stars cannot be Earthlike.
* Exoplanets are by definition not in our solar system.
* A quasar in the habitable zone of a star would probably destroy said star.
* Because the temperatures inside stars are higher than that which can support the existence of liquid water, stars cannot have subsurface oceans.
* Black holes do not have tectonic plates and cannot be tectonically active.

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

{{comic discussion}}