explain xkcd - User contributions [en]

2666: Universe Price Tiers

2022-09-02T01:14:10Z

172.70.114.215:

{{comic
| number = 2666
| date = August 31, 2022
| title = Universe Price Tiers
| image = universe_price_tiers.png
| titletext = In Universe Pro®™ the laws of physics remain unchanged under time reversal, to maintain backward compatibility.
}}

==Explanation==
{{incomplete|Created by a SOWN WIND - Explained the main point, more details needed. Please change this comment when editing the page . Do NOT delete this tag too soon.}}
Philosophers have posed many questions in trying to understand the nature of the universe. Some of these have become well-known in popular culture; while some are deliberately open-ended, several others are presented as a choice between two or more options, and are assumed to have a single answer, the debate being about which is correct. In this comic, Randall proposes that the answers to these questions are instead not fixed, but vary according to a tiered {{w|subscription business model}}, as seen in many business pricing schemes, particularly in software. In this model, the no-cost tier gets you a universe experience of a lower quality, while at higher tiers better options are available for a cost - for example in the highest tier the processes of aging and death are "Opt-in" rather than "Mandatory". It is not clear from the comic who is supposed to be paying these subscription fees, or to whom they are paid (presumably the developers or maintainers of the universe, or the {{w|Simulation hypothesis|hypothesized simulation thereof}}), or whose experience of the universe is supposed to be affected.

The universe does not have a subscription model,{{citation needed}} but on the chart some of the categories that refer to observable properties such as the speed limit or existence of the {{w|Uncertainty Principle}} indicate ours is the Universe Standard® subscription, but other specifications may not entirely match our user experience.

The title text refers to the concept of {{w|T-symmetry}} in physical laws. Most properties of our universe are asymmetric, meaning that the property changes if time is reversed (e.g. the entropy of the universe decreases as time flows backwards). Randall again makes a reference to software subscription models in a play on words as the Universe Pro®™ sub appears to have laws that maintain "backwards compatibility".

{| class="wikitable"
|-
! !! Universe Lite™ !! Universe Standard® !! Universe Pro®™!!Explanation
|-
! Price
| Free || $14.95/month || $49.95/month || Indicative of a typical Freemium product, the versions released include what is effectively an 'unlimited trial' version, but lacking some potentially desired features, and then extra tiers with increased functionality so that you can "get what you pay for".
|-
! Ads
| Yes || Yes || No || Again typical of a tiered subscription, where ad revenue supports the lower tiers. There are indeed ads in our own universe, but whether they are an intrinsic property of the universe or not is an open question.
|-
! Number of angels that can dance on the head of a pin
| 4 || 64 || 4,096 || "{{w|How many angels can dance on the head of a pin?}}" is a question used to poke fun at medieval angelology and medieval scholasticism in general by claiming discussions in its fields revolve around meaningless questions. It is also used as a metaphor for wasting time debating useless questions, as it is generally accepted that we can have no definititive answer. Here, the question is given concrete answers that are powers of 2 often seen when using binary representation. It may also be a reference to [[485: Depth]].
|-
! Free will or determinism
| Determinism || Free will || Free will || Another predominantly philosophical issue, although physics (both Newtonian and Quantum) has not shied away from trying to answer this (see Does God Play Dice? below). It is interesting that the paid versions of the universe are the only ones to include free will, implying that either such a quality is inherently desirable or it is a necessary condition of some other feature in the paid plan (such as, for instance, the dice-playing mentioned below).
|-
! Cosmic speed limit
| 65 mph || 300,000 km/s || Unlimited || The Cosmic speed limit refers to the {{w|speed of light}}, which rounds to 300,000 kilometers per second in our particular universe, one of the few definite clues as to which tier we might exist in. Living in a universe with such a low speed limit would render many aspects of experience unrecognizable from our own; assuming the speed of light and thus all relativistic effects were similarly scaled, the act of driving at highway speeds would result in [http://gamelab.mit.edu/games/a-slower-speed-of-light/ human-observable] time dilation and apparent spatial distortion. The {{w|special relativity}} consequences of a low speed of light are explored in one chapter of George Gamow's {{w|Mr Tompkins}}; in Mr Tompkins' dream, the speed of light is approximately 10 mph. The idea of having a speed cap is reminiscent of computer simulations and game engines, which often prevent agents from accelerating beyond a certain point to prevent unintended behavior.
|-
! If a tree falls in a forest and there's no one there to hear...
| No sound || Simple beep || Full sound || {{w|If a tree falls in a forest}} is a popular philosophical question whose answer depends largely on one's philosophical belief system and the interpretation of the question itself. Here it's suggested that there is a definite answer which differs depending on the quality of the universe subscription. On the assumption that "our" universe is on the Standard Plan, this table implies that all trees falling outside of the auditory range of anyone or anything capable of noticing it emit a simplified "beep" sound, rather than the complex crashing one would expect. This concept is similar to the discussion in [[2664: Cloud Swirls]].
|-
! Meaning of Life
| Unknowable || Uncertain || Clearly explained || All we can know is that we (currently) don't know, which makes our universe one almost certainly either with an unknowable or uncertain state of affairs.{{Actual citation needed}}
|-
! Sound of one hand clapping
| [None] || [None] || ''Kazzap!'' || A {{w|Koan}} from Buddhism. Koans deliberately have no answer — one hand cannot clap, as the sound of two hands clapping relies upon there being two hands percussing and displacing/resonating air. The "Kazzap" referenced is humorous because it provides an answer to something with no answer, in the form of a nonsense onomatopoeia. To members of our universe, this is absurd. The implication is that those in the Pro version of the universe have access to this seemingly impossible feat.
|-
! Aging and death
| Mandatory || Mandatory || Opt-in || If this is a mere option, we clearly haven't read (or understood) the online manual or perhaps read the tool-tips.
|-
! Does god play dice with the universe?
| Yes, and he cheats || Yes || No || A reference to a phrase famously ascribed to Einstein (in opposition to the concept of quantum uncertainty) that "God does not play dice with the universe." This option and the Determinism/Free Will choice, above, are interestingly linked but not necessarily in a way we can comprehend.
|-
! Bad things...
| Happen to good people only || Happen to good and bad people || Don't happen || Relates to whether there is justice, compassion or fairness in the universe, where good and bad events often seem uncorrelated with whether people morally deserve them. In theological arguments, this debate is intimately connected with theodicy (the problem of how a benevolent god could create a world that contains evil), but like the existence of free will it is hotly debated in non-theological contexts as well. Randall suggests that the situation in a lower-tier universe is even worse, and interestingly that there is no tier where bad things only happen to bad people.
|-
! What happens to those who sow the wind
| Reap the whirlwind || Reap the whirlwind || Lots of crops everywhere || This is a reference to the famous phrase "sow the wind, reap the whirlwind", taken from Hosea 8:7. The phrase means that those who do evil without thought to the consequences will receive punishment. However, in Universe Pro®™, nothing bad happens to anyone, which excludes the possibility of the "whirlwind". This implies that it is possible to ''literally'' sow wind (in the farming sense) in the Pro version, which apparently translates to growing crops in a vastly wider range than normal.
|}

==Transcript==
{{incomplete transcript|Do NOT delete this tag too soon.}}
{| class="wikitable"
|-
! !! Universe Lite™ !! Universe Standard® !! Universe Pro®™
|-
! Price
| Free || $14.95/month || $49.95/month
|-
! Ads
| Yes || Yes || No
|-
! Number of angels that can dance on the head of a pin
| 4 || 64 || 4,096
|-
! Free will or determinism
| Determinism || Free will || Free will
|-
! Cosmic speed limit
| 65mph || 300,000 km/s || Unlimited
|-
! If a tree falls in a forest and there's no one there to hear...
| No sound || Simple beep || Full sound
|-
! Meaning of Life
| Unknowable || Uncertain || Clearly explained
|-
! Sound of one hand clapping
| [None] || [None] || ''Kazzap!''
|-
! Aging and death
| Mandatory || Mandatory || Opt-in
|-
! Does god play dice with the universe?
| Yes, and he cheats || Yes || No
|-
! Bad things...
| Happen to good people only || Happen to good and bad people || Don't happen
|-
! What happens to those who sow the wind
| Reap the whirlwind || Reap the whirlwind || Lots of crops everywhere
|}
{{comic discussion}}
[[Category: Philosophy]]
[[Category: Religion]]

Talk:2660: Gen Z

2022-09-01T18:28:36Z

172.70.114.215: Found prior reference to the 1905 "yaghurt" quotation

It makes sense that Randall isn't calling out any particular fads, trends, tendencies, or commonalities in Gen Z to comment on, but some immediately came to my mind as I read the comic. Is it worth putting a list of possibilities in the explanation, or just one or two examples? That knowledge probably isn't going to contribute to the understanding of the joke, which is that for *every* generation there have been such observations and complaints from older folks. [[User:Dextrous Fred|Dextrous Fred]] ([[User talk:Dextrous Fred|talk]]) 21:28, 17 August 2022 (UTC)
:I don't think there's a need for that, but someone should add a definition of Generation Z. The Wikipedia page that it links to should describe the notable features of that generation. [[User:Barmar|Barmar]] ([[User talk:Barmar|talk]]) 22:41, 17 August 2022 (UTC)

I found the title text in the New Zealand Mail, Issue 1729, 19 April 1905, Page 15 (https://paperspast.natlib.govt.nz/newspapers/NZMAIL19050419.2.44).
:Not quite the same, though both articles were probably based on reading the same medical communication that one references. The Kansas one, however, appears to be the source of the quote in the comic. [[User:N0lqu|-boB]] ([[User talk:N0lqu|talk]])

holy shit randall is based --[[Special:Contributions/108.162.221.17|108.162.221.17]] 01:35, 18 August 2022 (UTC)
:Based on what? [[Special:Contributions/162.158.159.125|162.158.159.125]] 03:33, 18 August 2022 (UTC)
::Binary [[Special:Contributions/172.70.162.5|172.70.162.5]] 14:46, 18 August 2022 (UTC)
::Based is a term I have heard of, it means really like something but you say it in a jokey, possibly sarcastic way. [[Special:Contributions/172.70.206.163|172.70.206.163]] 06:10, 18 August 2022 (UTC)
::: https://www.urbandictionary.com/define.php?term=based [[User:Elektrizikekswerk|Elektrizikekswerk]] ([[User talk:Elektrizikekswerk|talk]]) 07:11, 18 August 2022 (UTC)

I'm pretty sure the five listeners represent the five generations between the {{w|Lost Generation}} (when {{w|Boater}} hats like the speaker is wearing were popular) and the Gen Z that he is talking about. The middle character with the flower in her hair is definitely a {{w|hippie}}, for the {{w|Baby boomers}}. I mentally associate the white {{w|Flat cap}} with post-WW2, which would be the {{w|Silent generation}}, although I'm not sure why I have that association. Extending this, the {{w|Millennial}} is the one saying "Gosh", the one in the black hat would be a {{w|Gen X|Gen Xer}} (no idea why), and the last one with the hairbun would be from the {{w|Greatest generation}}. I don't think I can describe those associations well enough to actually write it up, though. Does this view make sense to anyone else? -- [[User:Bobson|Bobson]] ([[User talk:Bobson|talk]]) 21:13, 18 August 2022 (UTC)

:I think that's an interesting interpretation, but I would invoke Occam's razor to suggest that the fashions depicted could all be from the early 1900s, and that the gathered crowd is composed of "small town salespeople in 1905" as the caption describes. I think if Randall wanted to make it clear they were from different generations, he would include more obvious cultural touchstones in their clothing or speech, and he wouldn't have them conversing with each other unless there were a reason to introduce time travel

I agree with the Elk Falls Journal correspondent. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 21:15, 18 August 2022 (UTC)

Is anyone else unable to load the page for comic 1962 when logged in? I can load it when logged out, but when I'm logged in I get an error. I pasted the error message to [[Talk:1962: Generations]]. --[[User:Orion205|Orion205]] ([[User talk:Orion205|talk]]) 23:24, 18 August 2022 (UTC)

I don't think French ever wrote "yaghurt". But it writes "yaourt". --[[Special:Contributions/172.71.130.127|172.71.130.127]] 07:12, 19 August 2022 (UTC)

The hats are: straw boater/skimmer, definitely of the 1905 period; perhaps homburg or fedora, mostly kind of the period; Greek fisherman’s cap, I say anachronistic. My impression is that such caps were popular in the 60s, 70s with men of the Greatest Generation. (Such as my father!) Randall has used that kind of hat to indicate elderly men in other comics, so maybe a joke? {{unsigned|BuckyE|15:35, 19 August 2022}}
: It's a cloth-type cap, but I think it far predates the '60s, etc. And while greek-sailors contemporary of '60s/'70s films do ring a bell, I had other classes and eras of person in mind.
: Anyway, if you look in [https://vintagedancer.com/1900s/1900s-mens-hat-styles-edwardian-era/ here in the Golf Caps section], and even a few of the images slightly above there, there seem to be styles which could have directly inspired what turned up to adorn the stick-figure heads in characature line-drawn form. [[Special:Contributions/162.158.34.61|162.158.34.61]] 20:25, 19 August 2022 (UTC)

I think all the characters are 1905 versions of the stock-characters in xkcd, I'd say from left to right they are White Hat, Megan, Black Hat, Science Girl, Cueball, and one more that I cannot figure out.[[Special:Contributions/172.69.69.208|172.69.69.208]] 18:50, 22 August 2022 (UTC)Bumpf
: OH DUH, THE LAST ONE IS HAIRBUN [[Special:Contributions/162.158.62.193|162.158.62.193]] 22:25, 28 August 2022 (UTC)Bumpf

It is possible that the alt text is an actual quotation from a 1905 cookbook, based on a reference from a cooking blog [https://sharonkreider.com/2021/11/09/the-joy-of-cooking/], however, the Internet Archive's Wayback Machine shows no record of this page from its 2021 archives, so it may be an elaborate retcon, including a dated comment from 2021. [[Special:Contributions/172.70.114.215|172.70.114.215]] 18:28, 1 September 2022 (UTC)Bill

2622: Angular Diameter Turnaround

2022-08-23T20:23:22Z

172.70.114.215: /* Explanation */ don't be so rude

{{comic
| number = 2622
| date = May 20, 2022
| title = Angular Diameter Turnaround
| image = angular_diameter_turnaround.png
| titletext = Thank you to Katie Mack for teaching me about this effect, and to Janelle Shane for describing redshifts as 'like galaxies sinking into a pool of dilute blood,' which is how I'll see them from now on.
}}

==Explanation==
{{incomplete|Created by a Galaxy-branded phone with minimal writing experience- Please change this comment when editing this page. Do NOT delete this tag too soon.}}
This comic references multiple physics and maths concepts, including {{w|Angular diameter}}, {{w|Angular diameter distance}}, {{w|Redshift}}, and {{w|phones|mobile phones}}, although mobile phones are not a core science at this time.{{Citation needed}}

The comic shows the galaxies of the universe as Samsung Galaxy mobile phones, pairing the age we see them at from earth, the degree they are redshifted, and how much of the sky they take up, known as their angular diameter. The mobile phones that are closer and older have depleted batteries, whereas the batteries are full for those phones from which the light is still only beginning to reach us. This is how galaxies appear in the sky if they were phones that had batteries lasting billions of years, the light reaching us from deeper into the past as it comes from objects that are farther away. Phones at a low battery may be a reference to [[1373: Screenshot]], where Randall commented that it is hard to pay attention to any phone with a low battery as the need to charge it is so urgent.

An important takeaway from this comic is that the events that occurred at the very start of our universe are etched in our sky ''as if they are still happening now'', in a detailed faint timeline, that we are still learning more and more from. Using the mobile phone metaphor helps as, when the technology space was young and smaller there were {{w|mobile phones}}, such as {{w|iPhone (1st generation)|the original iPhone}}, which one might still remember despite there being many more recent and better ones in a more crowded market space.

Randall's intent appears to be to highlight how just a few very distant galaxies occupy incredibly large proportions of the sky and are seen as they were at a very young age. Mobile phones have this similarity, of massive presence, relatively early stages of new technology, and bringing information from far away.

The large galaxies can be seen in dark red in the background as if the unimaginably ancient child galactic bodies are looming forebodingly behind everything else. The title text refers to galaxies falling into a pool of dilute blood as if the void beyond were hell. This isn't what redshift actually is {{Citation needed}} (rather, it's an effect on the wavelength of light, rather than light being filtered through regions of infernal suffering or far galaxies being stained by the blood of the enemies of Android phones), but is an evocative comparison.

This physical concept has a lot of juxtaposition of things that usually contradict, and Randall has put energy into attempting to highlight that.

Katie Mack tweet: https://twitter.com/AstroKatie/status/1516548836709343238

{{w|Spacetime diagram}} possibly has reasonable visualizations of the kinds of relations bodies have when they are moving this far apart, including angular diameter distance. Simultaneity no longer exists at such distances. Distance is debated too, although that would be a different article.

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

:[Cueball and a row of 7 spiral galaxies, the first 5 growing sequentially smaller and the last 2 growing larger]
:Angular Diameter Turnaround
:[A spiral galaxy emitting light and Cueball in a small circle with closely spaced grid lines, captioned "T=1b yr."]
:[A stretched truncated circle with widely spaced gridlines, with the galaxy at one side and Cueball on the other, and light following a curved path through the stretched space to Cueball, captioned "Now (T=13.8b yr.)". Cueball is thinking "Big!"]
:Illustrated using phones instead of galaxies
:(Brightness and redshift adjusted to keep phones visible)
:Things that are far away look smaller, but things that are ''really'' far away look ''bigger'', because when their light was emitted, the universe was small and they were close to us.
:[numerous iPhones scattered in space, with numbers visible on their lockscreen. The closest is brightly lit and says "13 billion years after the Big Bang" on the screen. Subsequent phones behind this one are smaller, fainter and more red, until they reach "3" (the rest of the text is too small to read). From this point, the phones grow larger, although they continue to get fainter and redder. Subsequent phones show "2", "1", "500 million", "200 million", "50 million", "20 million" (which is larger than the original "13 billion years after the Big Bang" phone) and a very large, faint phone so big that only the word "thousand" is visible, with the rest of the screen obscured behind other phones or so large it extends off the panel]

{{comic discussion}}
[[Category:Astronomy]]
[[Category:Math]]
[[Category:Physics]]
[[Category:Smartphones]]
[[Category:Comics with color]]
[[Category:Comics featuring real people]] 
[[Category:Puns]]