explain xkcd - User contributions [en]

Talk:622: Haiku Proof

2015-07-16T10:16:37Z

108.162.254.185:

A prime number must also be a natural number greater that one. {{unsigned|‎204.8.8.13}}

I removed the paragraph about the haiku being off, as it is not "top prime's divisors," but "top prime's divisors' " (notice the second apostrophe). So the question is actually what the (prime) factors of the product of all prime divisors plus one are. [[User:KillaBilla|KillaBilla]] ([[User talk:KillaBilla|talk]]) 21:57, 12 June 2014 (UTC)

: I've put it back, since the paragraph is correct - the proof is incorrect. That second apostrophe just means it is the product belonging to the top prime's divisors. The product of the top prime's divisors is just the top prime. --[[Special:Contributions/141.101.98.234|141.101.98.234]] 14:40, 5 April 2015 (UTC)
: "All primes' divisors'" would've been correct (although the "divisors" is still unnecessary). --[[Special:Contributions/108.162.254.185|108.162.254.185]] 10:16, 16 July 2015 (UTC)

Talk:1381: Margin

2014-06-15T10:31:40Z

108.162.254.185:

Isn't it possible that a mathematician knows about the existance or the proof of something, but doen't know how to technically do it? In this case, the margin remark would be accurate and not so funny. They have found a proof of existance for infinite information compression, but not yet discovered an actual method to do it. [[Special:Contributions/141.101.104.56|141.101.104.56]] 05:32, 13 June 2014 (UTC)
:Yes, when there's no example, it's called a {{w|pure existence theorem}}. If you actually demonstrate an example, that is a {{w|constructive proof}}. [[User:Mattflaschen|Mattflaschen]] ([[User talk:Mattflaschen|talk]]) 05:38, 13 June 2014 (UTC)
::Actually the proof of the Shannon-Hartley theorem is non-constructive. It tells you the data rate of the best possible channel coding, but does not tell you how to achieve it! [[Special:Contributions/108.162.215.47|108.162.215.47]] 07:58, 13 June 2014 (UTC)
Setting font-size to 0 would be the same as not ''printing'' any information at all, you'll still use the same number of bits and be able to send the text to other computers which can read the information. The Shannon-Hartley theorem is, as far as I can see from the wikipedia article, about analogue channels anyway. --[[User:Buggz|Buggz]] ([[User talk:Buggz|talk]]) 06:16, 13 June 2014 (UTC)
:The Shannon-Hartley theorem is about sending digital data (over analogue channels but you cannot send them over anything else in real world anyway). Nevertheless, you are right that setting the font size won't change the number of bits needed to be sent (font size specifies the size of the representation, not the information itself) therefore it won't change the limit. [[User:Sten|'''STEN''']] ([[User talk:Sten|talk]]) 22:12, 13 June 2014 (UTC)

Isn't this also a reference to {{w|Jan Sloot}}'s digital compression mechanism where a movie would fit into 8 kbyte? [[User:Kaa-ching|Kaa-ching]] ([[User talk:Kaa-ching|talk]]) 07:36, 13 June 2014 (UTC)

This was my first time editing Explain XKCD, but I fear I may have went too far in replacing the current explanation of the title-text with my own and removing the incomplete tag. Is it OK? [[User:YatharthROCK|YatharthROCK]] ([[User talk:YatharthROCK|talk]]) 08:10, 13 June 2014 (UTC)
:I think you title text explain seems fine (I have not checked on the Shannon theorem.) But I think it is too soon to make this explain marked as complete. So I have undone that. Great to have one more to edit the explain so keep up the good work. [[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 10:46, 13 June 2014 (UTC)

Is the problem behind Fermat's Last Theorem "deceptively simple" or "deceptively difficult"? I've never quite worked out which way it should be. Unlike "cheap at half the price" which really should be "cheap at twice the price" and the effect of putting in the word "only" into "glass ... half full/empty". But I bet you all could care less (or, more accurately, "''couldn't'' care less", because you already do not care at all), right? ;) [[Special:Contributions/141.101.98.232|141.101.98.232]] 11:44, 13 June 2014 (UTC)
:I believe the correct wording would be "deceptively difficult". Deceptively simple would imply that the problem looked quite difficult on the surface, but once work had begun it was found to be quite simple. Fermat's last theorem goes the other way. It is simply stated with very few elements, so it would seem the proof should be easily constructed, but is actually quite difficult. {{unsigned ip|173.245.50.72}}
::Unfortunately "deceptively easy" could also mean the opposite: it's easy, but only as a deception, so it's actually difficult. As of now, not even linguists have settled the question. It is just better to avoid the word unless the context can disambiguate the meaning. [[Special:Contributions/141.101.99.32|141.101.99.32]] 05:14, 14 June 2014 (UTC)

Is it at all possible that the exclamation: "oh," represents the discovery of an earlier proof (perhaps even better than the one purported) all ready in the margin? That would explain the next exclamation: "never mind." This is a comic after all. And what's with the unreadable Lorem Ipsum text (perhaps a proof in itself)? Of course, the unhappy face (after "never mind") is a visual image compression mechanism that may deserve comment as well. [[User:Run, you clever boy|Run, you clever boy]] ([[User talk:Run, you clever boy|talk]]) 14:36, 13 June 2014 (UTC)

;Why bury descriptions of the beautiful inspiration behind these great comics in an afterthought "trivia" section?

I think explanations of the beautiful inspirations for these comics (like Fermat's last theorem, here) should be highlighted in the main part of the article, not buried below the transcript and demeaned with the label "trivia". [[User:Nealmcb|Nealmcb]] ([[User talk:Nealmcb|talk]]) 12:46, 13 June 2014 (UTC)
:Well there is a link from the relevant part. The inspiration of this comic is that someone wrote a statement in a margin and did not have space for the proof. It is not the theorem in it self that is the inspiration. Writing about Phytagoras and formulas in the explain is maybe a little too much. I think it belongs well in the trivia section and it is not buried - with this short transcript you can easily see there is more to the explai. [[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 05:49, 14 June 2014 (UTC)

"" leading many to believe that he didn't actually possess a (correct) proof"" Of course Fermat did not have a proof.
Was that margin the only free piece of paper in France then?
For that reason in German one does not speak of Fermats "theorems", but the names used are
Fermat's little or resp. big problem. If some nobody had written that margin, of course
that would have been named a conjecture at best. Because Fermat was a real "big shot",
a medium expression is used: "problem". But never theorem, because a theorem without
proof isn't a theorem.
17:18, 14 June 2014 (UTC)[[Special:Contributions/108.162.254.138|108.162.254.138]]
:Who says he did not write his proof somewhere else, on a paper that was lost. It is only because the book was easily sored that we have all of Fermat's theorems. There were many in his book, and all of them - including the last - turned out to be true theorems. I do not believe he had the proof - but that is beside the point. If it had been a nobodu, then the book would never have been investigated... Anyway this has of course nothing to do with this explanation - but an interesting observation here in the talk page ;-) [[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 07:11, 15 June 2014 (UTC)

What if the margin text is the compiled form of the proof? [[Special:Contributions/141.101.105.187|141.101.105.187]] 04:46, 15 June 2014 (UTC)
:Then he would not have written the oh... :( never mind [[User:Kynde|Kynde]] ([[User talk:Kynde|talk]]) 07:11, 15 June 2014 (UTC)
::Maybe the "oh... nevermind" is part of the proof... --[[Special:Contributions/108.162.254.185|108.162.254.185]] 10:31, 15 June 2014 (UTC)

Talk:1024: Error Code

2014-06-07T09:35:47Z

108.162.254.185: .

The joke is probably that "sit by a lake" is the name of the tune corresponding with motherboard error -41

Motherboard error codes are not numbered like other error codes are. Motherboard error codes are just referred to by how the beeps sound (ex. 1 long, 2 short) [[User:Luke1042|Luke1042]]

Personally, of all motherboard beeping codes, I always liked "No beep = Power supply, system board problem, disconnected CPU, or disconnected speaker...." (Well, when not suffering it myself. And even then I could stand it when it was just the latter and thus of no ''immediate'' consequence...) [[Special:Contributions/31.111.103.76|31.111.103.76]] 22:04, 2 April 2013 (UTC)

: Well then, laptop computers dont beep at all, I guess that must mean that something is always missing --[[Special:Contributions/108.162.250.111|108.162.250.111]] 03:03, 26 November 2013 (UTC)

::Yes. You are missing a Desktop. [[Special:Contributions/108.162.216.60|108.162.216.60]] 20:49, 14 May 2014 (UTC)BK201

This is one of my favourite xkcd comics, it makes me take a long breath and just chill out a bit. Probably the only comic that could be described as 'relaxing' [[Special:Contributions/77.103.5.201|77.103.5.201]] 20:13, 5 May 2013 (UTC)

Unfortunately the beep codes thing is archaic. Most new computers built since the early to mid-2000s haven't made a beep - instead, the trend has been to rely on visual codes from built-in LEDs (and, later on, from pairs of eight-segment displays relaying hex codes). So a modern code will run from 00 to FF - but it will also be completely silent. [[Special:Contributions/141.101.81.216|141.101.81.216]] 11:47, 25 February 2014 (UTC)

The guy at the computer is [[Cueball]], isn't he? So Cuball and friend is the common way here. If not, the the category [[:Category:Comics featuring Cueball]] has also to be removed. But I don't see that. --[[User:Dgbrt|Dgbrt]] ([[User talk:Dgbrt|talk]]) 20:02, 23 April 2014 (UTC)

The guy at the computer should say at the first panel "That's UNhelpful" instead of "That's helpful", shouldn't he? Or maybe I don't know something in english? [[Special:Contributions/108.162.254.185|108.162.254.185]] 09:35, 7 June 2014 (UTC)

Talk:1361: Google Announcement

2014-04-28T09:21:22Z

108.162.254.185:

"The service was announced on 3 December 2009" - http://en.wikipedia.org/wiki/Google_Public_DNS [[Special:Contributions/108.162.254.179|108.162.254.179]] 05:31, 28 April 2014 (UTC)

----

'''ubuntu one?'''
Isn't this a reference to Ubuntu shutting down Ubuntu One "focus our efforts on our most important strategic initiatives and ensure we are not spread too thin" http://blog.canonical.com/2014/04/02/shutting-down-ubuntu-one-file-services/
Randall mentions using Linux quite a bit. U1 was a pretty convenient service for linux users. Many users complain about Ubuntu depreciating various important features. U1 was something that made Ubuntu practical for people using Mac and windows because of the cloud sharing so may be seen as part of a core mandate for ubuntu. The joke is that this is foolish to shut down, it would be akin to Google shutting down all their important services to focus on the DNS core because technically it is more important. (but obviously not to most google users who have no idea what 8.8.8.8 is)

I was pretty sure this was about ubuntu because it seems like a strong parallel... but then I thought that was a bit obscure... so I came here to check it out and I suppose maybe I am the only one who sees the connection?
[[Special:Contributions/108.162.245.11|108.162.245.11]] 07:51, 28 April 2014 (UTC)

For some reason I thought 8.8.8.8 was a reference to the Penfield Mood Organ in ''Do Androids Dream of Electric Sheep''. I have no clue why I thought this because it has nothing to do with Google. Maybe its because dialing 888 gives people the desire to watch TV no matter what's on. Either way, I realize that my idea would be too obscure and have nothing to do with the original comic.[[Special:Contributions/173.245.48.90|173.245.48.90]] 09:19, 28 April 2014 (UTC)

I'll start panicking only after Google switches its public DNS server to 6.6.6.6 - [[Special:Contributions/108.162.254.185|108.162.254.185]] 09:21, 28 April 2014 (UTC)

Talk:1356: Orbital Mechanics

2014-04-25T10:32:32Z

108.162.254.185:

I just put in a first attempt at the explanation. Could do with links to pages regarding KSP, etc, etc. (Or rewrite entirely how it ought to be done, of course.) Also, if anyone knows ''for sure'' that "aim nose at destination, fire retros", as seen in the film Gravity, would or would not give the desired effect, that'd be useful to clarify or dismiss. From my own experience with the Kerbals, it wouldn't (never mind all the other broad assumptions made in that otherwise spectacular film  ), but KSP ''also'' rather fudges away the N-body problem, artificially. [[Special:Contributions/141.101.88.209|141.101.88.209]] 05:38, 16 April 2014 (UTC)

:You are correct that "aim nose, fire retros" doesn't work in reality. KSP fudges the n-body problem by putting the planets and moons on tracks, and then changing you into a different 2-body problem when you cross into a smaller {{w|hill sphere}} than the one you were in. The maneuver node system does a little bit of n-body work when you get a maneuver close to another body, but you'll notice that when the ship actually crosses into the other hill sphere the trajectory for the maneuver goes weird. It's a rather clever optimization for a simulator like KSP. [[User:Lcarsos|lcarsos]]_a ([[User talk:Lcarsos|talk]]) 06:21, 16 April 2014 (UTC)

I really wish there was a downwards curve for "I saw Armageddon". [[Special:Contributions/108.162.221.60|108.162.221.60]] 06:26, 16 April 2014 (UTC)

:There will be a huge upwards curve on "how much I think i know about orbital mechanics" - See {{w|Dunning-Krueger effect}} for more info. --[[Special:Contributions/108.162.229.77|108.162.229.77]] 14:40, 16 April 2014 (UTC)

;Future mission failure due to discrepancies in Kerbal Space Program
I note some differences in KSP (from wikipedia):

:The game simulates trajectories and orbits using patched conic approximation instead of a full n-body simulation, and thus does not support Lagrange points and halo orbits.

:The celestial bodies in the Kerbal solar system are about 1/10 the radius of their real-universe equivalents yet have comparable surface gravity, implying that they have unrealistically high densities. This change to scale makes many tasks considerably easier. For example, a surface to low-Kerbin-orbit launch requires a delta-v of about 4.5 km/s, compared to 9.5 km/s for a low-Earth-orbit launch. In particular, because of the game also having unrealistically efficient and flexible (in terms of speed and altitude) turbojet engines, this means it is much easier to make a single-stage-to-orbit vehicle using jet engines to accelerate a vehicle to orbital speed on only a small fraction of its mass in jet fuel, then give a tiny boost with rockets to reach orbit, whereas in real life, a highly efficient but powerful and lightweight scramjet would be necessary to do the same with several times the amount of fuel.

So I predict some probability that, after reading this comic, some NASA person will make the mistake of designing real missions using notions or designs from it, which will fail in real life (or at least be ridiculed at mission design review time). And then Randall will have to write a really challenging comic about it..... [[User:Nealmcb|Nealmcb]] ([[User talk:Nealmcb|talk]]) 13:12, 17 April 2014 (UTC)

: Maybe Randall should add a horizontal line well over the curve, labelled: ''Level of knowledge required for a successful mission in real life'' - [[Special:Contributions/108.162.254.185|108.162.254.185]] 10:32, 25 April 2014 (UTC)

''Once at that lower orbit, your velocity is faster'' ... really? I though that on lower orbit, your velocity is slower BUT your {{w|Angular_velocity|ANGULAR velocity}} is faster, which is the reason you start to overtake your target ... but I never played Kerbal, so I may be wrong. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 23:37, 24 April 2014 (UTC)