explain xkcd - User contributions [en]

Talk:501: Faust 2.0

2014-03-25T18:19:32Z

173.245.53.163: Created page with "It's also a reference to cd sleeve seals that say "by tearing this seal you agree to the enclosed license agreement" as it is obvious that mephistopheles has already entered t..."

It's also a reference to cd sleeve seals that say "by tearing this seal you agree to the enclosed license agreement" as it is obvious that mephistopheles has already entered the room [[Special:Contributions/173.245.53.163|173.245.53.163]] 18:19, 25 March 2014 (UTC)

636: Brontosaurus

2014-02-16T19:23:07Z

173.245.53.163: /* Explanation */ Some interpretation of the title text in relation to the comic

{{comic
| number = 636
| date = September 14, 2009
| title = Brontosaurus
| image = brontosaurus.png
| titletext = Well, sex is like a velociraptor: despite your movie-fueled lifelong neurotic obsession, unlikely to be found in your house.
}}

==Explanation==
Megan describes her relationship to Cueball with the simile "our love is like a turtle," a comparison often made when referring to a shy and slowly developing yet steady sort of romance. However, Cueball thinks the {{w|Brontosaurus}} the better impersonation. His explanation refers to the fact that remains of {{w|Apatosaurus}} were by mistake believed to be a different species which the paleontologist {{w|Othniel Charles Marsh|O.C. Marsh}} named ''Brontosaurus''. It was later discovered that the two species should be classified as one, with the older name prevailing according to convention. The term Brontosaurus is therefore a scientific redundancy.

Applied to the scenario in the comic, Cueball apparently considers the relationship without any emotional foundation and only continues it out of nostalgic motives. This conclusion counteracts the initial romantic tone adopted by the turtle simile, as comparing a romance with a falsely classified fossil is one of the least charming statements imaginable.

The title text aims at Randall's well-known enthusiasm for {{w|Velociraptors}} which he mockingly compares to the obsession others might cherish for sex. It can be interpreted as the answer of Megan, who tells Cueball that she refuses to have sex with him any more, using a similar comparison. Possibly, Megan also predicts that he won't find any other sexual partner with that attitude.

Randall has previously mentioned the Brontosaurus name change in [[460: Paleontology]]. The Apatosaurus also appears in [[15: Just Alerting You]] and [[650: Nowhere]].

==Transcript==
:[Cueball and Megan are sitting at a bench. Megan is holding a turtle.]
:Megan: Our love is like a turtle.

:[Megan sets down the turtle and turns to Cueball. They hold hands.]
:Megan: Humble and simple, enduring by virtue of perfect design.

:Cueball: Our love is like a brontosaurus.

:Cueball: Recognized as a mistaken combination long ago, lingering only out of misplaced affection for an imagined past.

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Comics featuring Megan]]
[[Category:Velociraptors]]
[[Category:Romance]]
[[Category:Apatosaurus]]

505: A Bunch of Rocks

2013-12-09T13:56:17Z

173.245.53.163: /* Explanation */

{{comic
| number = 505
| date = November 17, 2008
| title = A Bunch of Rocks
| image = a_bunch_of_rocks.png
| titletext = I call Rule 34 on Wolfram's Rule 34.
}}

==Explanation==
{{incomplete}}
[[Cueball]] awakens to find himself trapped for eternity in an endless expanse of sand and rocks. At first, he uses this time to derive all of mathematics and physics, including {{w|quantum mechanics}} and {{w|general relativity}}. The Swiss patent office line refers to {{w|Albert Einstein}}, who supposedly came up with the idea for general relativity while bored at work as a Swiss patent clerk.

Next, armed with infinite time and space (and rocks), Cueball uses the rocks to build a {{w|cellular automaton}}, a computational model based on simple rules to advance from one state to the next. Certain cellular automata are {{w|Turing-complete}}, which means that they can be used to represent any computer program (given finite-but-possibly-extremely-large time and space). He specifically seems to be running Wolfram's {{w|Rule 110}}, which is indeed capable of universal computation. Cueball then uses his enormous, hand-powered computer to simulate a universe.

When using Rule 110 for universal computation, one builds a background pattern, which can be seen in the comic (especially panels 12 and 20) as the nigh-universal pattern of smaller triangles, and then performs computation by sending out "rockets" (the patterns of larger triangles seen in panel 20) to collide and interact with each other (for example, the triangular outlines in panel 13).

The last panel then implies that the universe Cueball is simulating is, in fact, ''our'' universe. In panel 24, Cueball mentions he must have made a mistake in the last "billions of billions of millenia." A millennium is a thousand years, which implies that the time needed to run this computer through a single step of computation is trillions of years. This means he spends much more time on a single step of computation than our universe has spent existing, and this single step of computation simulates an extremely short span of time (a {{w|Planck time}} most probably); to put this massive difference into perspective, our universe is around 13.772 billion years old, which corresponds to roughly 8,060,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000 years of Cueball's computation. (Give or take a few duodecillion years.) Suffice to say, this is a ''very'' long time.

The diagrams in panel 8 are, from left to right: A {{w|Gaussian function}} (probably the {{w|Normal distribution}}); the {{w|Inclined plane#History|Epitaph of Stevinus}}; a weird diagram with lines in it (something to do with thermodynamic cycles?).

[[Rule 34]] is a humorous rule of the Internet which states "If you can imagine it, there is porn of it. No exceptions." {{w|Elementary cellular automaton#Random initial state|Wolfram's Rule 34}} is a cellular automaton. Randall is suggesting that someone should make pornography featuring the cellular automaton in question. This might prove to be quite challenging as Wolfram's Rule 34 quickly devolves into a bunch of diagonal lines given almost any input.

==Transcript==
:[Cueball is walking, alone in desert, narrating his own situation.]
:So I'm stuck in this desert for eternity.
:I don't know why. I just woke up here one day.

:I never feel hungry or thirsty.

:I just walk.

:Sand and rocks

:stretch to infinity.
:As best as I can tell.

:[Cueball is sitting in the desert, in a contemplative position.]
:There's plenty of time for thinking out here.
:An eternity really.

:[Cueball is sketching stuff in the sand.]
:I've rederived modern math in the sand
:and then some.

:[Different graph types are depicted.]
:Physics too. I worked out the kinks in quantum mechanics and relativity.
:Took a lot of thinking, but this place has fewer distractions than a Swiss patent office.

:[Cueball is walking along the desert, laying out rocks.]
:One day I started laying down rows of rocks.

:[Cueball continues to deploy rocks.]
:Each new row followed from the last in a simple pattern.

:[Image continues to zoom out showing laid out rocks.]
:With the right set of rules and enough space,

:I was able to build a computer.
:Each new row of stones is the next iteration of the computation.

:Sure it's rocks instead of electricity, but it's the same* thing.
:Just slower.
:<nowiki>*Turing-complete</nowiki>

:[Cueball in contemplative pose.]
:After a while, I programmed it to be a physics simulator.

:[Image of binary encoding depicted in rocks.]
:Every piece of information about a particle was encoded as a string of bits written in the stones.

:[Representations of two particles interacting.]
:With enough time and space, I could fully simulate two particles interacting.

:[Cueball standing before the vastness of the desert.]
:But I have infinite time and space.

:[Depiction of a universe.]
:So I decided to simulate a universe.

:[Cueball is walking about his rocks, changing placement.]
:The eons blur past as I walk down a single row.

:[Zoom out of the rows of rocks.]
:The rows blur past to compute a single step.

:[Shows placement of two rocks.]
:And in the simulation...

:[The two rocks have moved; an after-image of their previous placement is present.]
:...another instant ticks by.

:[A person observes a mote of dust vanish.]
:So if you see a mote of dust vanish from your vision in a little flash or something

:[Cueball is rearranging rocks.]
:I'm sorry. I must have misplaced a rock
:sometime in the last few billions and billions of millennia.

:[Cueball in front of the vastness of his infinite desert.]
:Oh and...

:[Cueball is in a classroom setting, girl and professor are present.]
:If you think the minutes in your morning lecture are taking a long time for <u>YOU</u>...

{{comic discussion}}
[[Category:Comics featuring Cueball]]
[[Category:Physics]]