explain xkcd - User contributions [en]

Talk:1229: Screensaver

2013-06-24T07:34:32Z

87.238.84.65:

This is my first time contributing to the site and my first time posting a comic up. If I've missed something, then please let me know. Thanks. --[[User:James Chin|James Chin]] ([[User talk:James Chin|talk]]) 07:02, 24 June 2013 (UTC)

I can't stop thinking that the last panel is not "noise" but a binary coded message/file. It seems just enough compressed/unsharp to make it possible to read out every pixel as a bit, and perhaps there is some kind of "datafile" with error correction? Anybody tought about that? --[[Special:Contributions/217.253.152.222|217.253.152.222]] 07:22, 24 June 2013 (UTC)

How do you know it is Cueball who tries to shoot the flying toasters?

Talk:1168: tar

2013-02-01T10:06:12Z

87.238.84.65:

I thought the title text would be "tar --help"
[[Special:Contributions/123.202.19.132|123.202.19.132]] 06:59, 1 February 2013 (UTC)

The comic is about the difficulty of the tar program options.

Even if his life depended on it and after years of usage, Bob/Randall could not come up with the right parameters without looking them up. So a situation is shown, where Bob's life depends on coming up with the right parameters:

* It shows an atomic warhead
* It has a user interface, which requests any valid tar command
* If it is not entered on the first try within 10s, the bomb is not disarmed and potentially explodes on the spot

Randall has come up with a situation, where the unix guy Bob can be the hero by knowing tar parameters. This is a pipe dream of a geek; nobody cares IRL, if you know tar parameters on the first try.

It is hilarious, that
* the bomb says in full detail the rules including that you should not cheat and it probably has no means to check whether you cheated. This is no game, but feels like one. In war and love every means is allowed - even cheating; it would also be self-defense for disarming the bomb; Bob and his colleagues are not even considering to cheat.
* the user has root access to the bomb, shown by the bomb as ~#, the tilde is the home directory, the # signifies super-user rights; even if the available programs prevent the bomb from being shutdown or disabled by a nonintended way, normally no root access is given for users of linux devices during normal usage; and disarming the bomb with official rules is normal usage of a bomb; a root prompt should not be necessary, if the bomb software is designed and configured well; possibly the unix prompt is a simulation for entering an answer
* Bob shurely needs more than 10s to come. So the bomb will have announced that questions, which require unix knowledge will follow - or has already asked other Unix questions; perhaps after 10s without entering anything a new question comes up
* this bomb can be disarmed with "common knowledge"

Small notes:
* The screen looks to be really grayscale (esp. the inverted "TEN") - not just because of the comic; it has at least 3 colors (black, white, tar gray); it could be that the "TEN" is updated dynamically and is thus inverted
* The comic is quite black: The screen and the bomb; Randall seldomly uses solid black areas; the bomb is a gloomy topic so it is black like "tar" (pun)

Sebastian --[[Special:Contributions/178.26.121.97|178.26.121.97]] 07:24, 1 February 2013 (UTC)

I think there is a visual double pun in this strip: the bomb disarmed by a tar command is a reference to the [[wikipedia:Tar (computing)#Tarbomb|tarbombs]], but it also looks like the [[wikipedia:File:Tsar Bomba Revised.jpg|Tsar Bomb(a)]]. --[[User:Koveras|Koveras]] ([[User talk:Koveras|talk]]) 08:24, 1 February 2013 (UTC)
: I don’t think it looks like Tsar Bomba. If anything, it is much more similar to [[wikipedia:Fat Man|Fat Man]]. --[[User:Mormegil|Mormegil]] ([[User talk:Mormegil|talk]]) 08:38, 1 February 2013 (UTC)

I think another joke is in the fact that you don't know which Unix is running on the bomb so you don't actually know which parameter layout is supported. tar --help for example may or may not be valid since -- is a GNU extension.

Talk:1162: Log Scale

2013-01-28T14:45:13Z

87.238.84.65:

The fictional notation MAY BE a parody of Knuth's up-arrow notation - and uranium MAY BE an effective energy source. By the way, labeling the energy sources just with material name is insufficient: how good energy source is hydrogen? -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 09:17, 18 January 2013 (UTC)
:It has a calorific value of about 150 kJ/gm(much higher when compared to coal,etc.) but is too explosive[[User:Guru-45|Guru-45]] ([[User talk:Guru-45|talk]]) 14:24, 18 January 2013 (UTC)
:That is for burning it I assume? But what if you use it as fuel in a fusion reactor? Or an H-Bomb for that matter?
The calorie standard is defined by burning. So comparison doesn't fit with the graph as written. [[User:DruidDriver|DruidDriver]] ([[User talk:DruidDriver|talk]]) 20:46, 24 January 2013 (UTC)
:is it really a parody? (well, probably arrow notation grows much more, here there is just a log log log etc) --[[User:.mau,|.mau.]] ([[User talk:.mau,|talk]]) 14:10, 18 January 2013 (UTC)
It's true that uranium has an extremely high energy density, which is of great importance for mobile power plants; however, nuclear fission has a lot of safety issues, especially for mobile power, which is why it is used only for stationary power plants and large military vessels, such as aircraft carriers and subs.

Hydrogen is pretty good when highly compressed so as to get high energy volume density as well, but that leads to problems too. Also, hydrogen leaks more easily than almost anything else. That is especially a problem for an extremely flammable gas. On the plus side for hydrogen, nothing burns more cleanly.

:"The log scale can also be abused to make data look more uniform than it really is, so on a log scale sugar and other materials would look largely equal energy density when they clearly are not."
I think this is missing the point, which I take to be that displaying the data on a log scale would understate the vast difference between ''uranium'' and the hydrocarbons/carbohydrates:
E/m log(E/m)
sugar 19 1.3 *
coal 24 1.4 *
fat 39 1.6 **
gas 46 1.7 **
uranium 76e6 7.9 ****.***
Uranium is clearly larger than the others, but only by a factor of 4, so the real magnitude of the difference may not be appreciated.
With the stack of paper, he's proposing a way to show linear values for the data without having the uranium column simply shooting off the top of the page, with an arrow and the number. [[User:Wwoods|Wwoods]] ([[User talk:Wwoods|talk]]) 17:26, 18 January 2013 (UTC)
: or, he could just print at a scale that allows 76,000,000 to fit on the page, with the other values shown as near-infinitesimally thin lines. [[Special:Contributions/67.51.59.66|67.51.59.66]] 18:23, 18 January 2013 (UTC)

A googolplex in Knuth's paper stack notation (based upon 3818 chr per page, and 25,824 pages to fill up a typical 8ft tall room), would be:
96.41816408 with a 2 pinned on it.

The algorithim is:

KnuthPaperStack(N):

y = log10(N)/3818

If y >= 25824
Z = Z + 1
z = KnuthPaperStack(y)
Return z,Z
Else
Return y,Z
End if

--[[User:Markozeta|Markozeta]] ([[User talk:Markozeta|talk]]) 15:25, 20 January 2013 (UTC)

I think the name "Knuth paper-stack notation" sounds like "'Nuff paper-stack notation", meaning that it is a notation in which you need "enough paper" to stack up.

--[[User:NiccoloM|NiccoloM]] ([[User talk:NiccoloM|talk]]) 00:46, 21 January 2013 (UTC)

Isn't there a pun on Log which is itself an energy source as well as being the source of any reams of paper used to record values.
[[Special:Contributions/192.11.175.219|192.11.175.219]] 06:58, 22 January 2013 (UTC)

Am I the only one not seeing the glaring mistake on the comic? First thing I thought was "that stack of paper is not high enough!". Please someone double check my math: If the height has to be 6.6e6cm (stated above) at 29.7 cm each A4 (vertical), that would mean 222,222 sheets of paper one on top of another. Each stack of 100 pages is aprox 1cm high. That would represent the stack to be 2222cm high, ergo 22m, roughly a 7 story building. Unless there is the equivalent of 6 stories in the waving paper, or the length of the folding 7x that of an A4, or the stick figure is 7 times closer to the camera than the stack of paper is... '''THE HEIGHT OF THE PILE IS OH SO WRONG'''!!!!!! Please prove me wrong!

[[Special:Contributions/87.238.84.65|87.238.84.65]] 14:45, 28 January 2013 (UTC) Guest, 2nd time posting :)

Talk:1163: Debugger

2013-01-28T14:35:36Z

87.238.84.65:

Isn't this also a reference to the [http://en.wikipedia.org/wiki/Halting_problem halting problem]? [[User:DonGoat|DonGoat]] ([[User talk:DonGoat|talk]]) 08:33, 21 January 2013 (UTC)

:It may be, but it isn't an INSTANCE of halting problem. You can understand how something work without being able to predict what exactly it will do. The problem may be also related to the [http://en.wikipedia.org/wiki/G%C3%B6del%27s_incompleteness_theorems Gödel's incompleteness theorems], which basically states that any nontrivial theory cannot be proven consistent and complete in itself. -- [[User:Hkmaly|Hkmaly]] ([[User talk:Hkmaly|talk]]) 09:15, 21 January 2013 (UTC)

It's also reminiscent of a joke: ''"I was saying to myself that a brain is truly a wondrous creation with its complexity and power. And then I realized '''who''' is saying that to me."'' -- [[User:Edheldil|Edheldil]] ([[User talk:Edheldil|talk]]) 10:59, 21 January 2013 (UTC)

Not sure if it's relevant, but it reminds me of a quote: 'If our brains were simple enough for us to understand them, we'd be so simple that we couldn't' by Ian Stewart. (Yeah, I do know it from Civilization 4.) [[User:Lmpk|Lmpk]] ([[User talk:Lmpk|talk]]) 20:22, 21 January 2013 (UTC)

If the "Report a bug" page stopped working, and it was a site with some traffic, it's administrators ''could'' find out by noticing there were no more bug reports by users. The lack of bugs reported would point to a bug. Or a great deal of arrogance. -- [[User:Martin42|Martin42]] ([[User talk:Martin42|talk]]) 05:04, 22 January 2013 (UTC)

:You made a series of assumptions here in your attempt to overthrow the bug analogy - 1. The "Report a bug" page used to work at some point in time; 2. The site had traffic, meaning that the site had previously been online; 3. The users of the site had been consistently using the "Report a bug" page to report bugs (because, you know, I always just leave the site without caring enough to submit a bug report); 4. Someone actually reads the bug reports and does something about them. Judging by how specific your example is, I don't believe you can successfully use that one instance to claim that the analogy does not accurately describe the situation in general. [[User:NiccoloM|NiccoloM]] ([[User talk:NiccoloM|NiccoloM]]) 00:34, 23 January 2013 (UTC)

Also note the title "debugger." Most computer programmers don't understand how a [http://en.wikipedia.org/wiki/Debugger debugger] works, but they rely on it to understand how their code works. -- [[User:Paul42|Paul42]] ([[User talk:Paul42|talk]]) 16:49, 24 January 2013 (UTC)

Somehow related, an actual problem when people start losing their mental capabilities, typically due to age. Both my parents (age around 80) are starting to have important lapses of judgement, and because they evaluate their behavior with their mind, they refuse to accept any issues in their thought process. As I'm witnessing this, I wonder the same think as the character does: ''I don't understand how my mind works, I wonder if it's working alright, but I use my mind to evaluate it...'' [[Special:Contributions/87.238.84.65|87.238.84.65]] 14:35, 28 January 2013 (UTC)Guest, 1st time posting.