## Search found 775 matches

Sun Jun 21, 2015 11:37 am UTC
Forum: Mathematics
Topic: Why is 0! = 1?
Replies: 6
Views: 2520

### Re: Why is 0! = 1?

If n! means "the number of ways to arrange n objects in a sequence", then 0! is 1 because there's exactly one way to arrange nothing. Here it is (quoted for visibility):

Sun Jun 21, 2015 11:21 am UTC
Topic: Encode a message so it can't be read until a certain time?
Replies: 84
Views: 55007

### Re: Encode a message so it can't be read until a certain tim

We can go home now, someone figured it out . It's still limited by computing power, so a faster computer can decode the message first. The clever bit is that encoding the message can be parallelized, so you can do it on a supercomputer or a GPU cluster. Decoding takes just as many CPU-years, but can...
Mon May 25, 2015 6:08 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1529: "Bracket"
Replies: 191
Views: 51347

### Re: 1529: "Bracket"

The Doctor is between Dr. No and Cory Doctorow. And he's up against some serious competition in the second round... In the first round, even. The Doctor versus Cory Doctorow? That's the one I want tickets for. Does the image itself look really messed up to anyone else? bracket.png Your version of t...
Wed Apr 22, 2015 7:27 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1515: "Basketball Earth"
Replies: 48
Views: 13352

### Re: 1515: "Basketball Earth"

In the first panel, is BHG pushing the Earth closer to the Moon to create ridiculous tides? Or is he just poking the ocean to watch the pretty ripples?
Wed Apr 01, 2015 10:17 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1506: "xkcloud"
Replies: 101
Views: 28761

### Re: 1506: "xkcloud"

You can draw things, Kat.

I believe in you! You can do it!
Fri Mar 13, 2015 4:54 pm UTC
Forum: Mathematics
Topic: Fictional but natural Time Lord mathematical system
Replies: 11
Views: 3515

### Re: Fictional but natural Time Lord mathematical system

Now this is just ridiculous.

Larger digits should be on the outermost circle, not the innermost. That way the most significant digits are bigger, and infinite decimal expansions just become a sequence of ever-smaller circles eventually receding into invisibility.

Mon Feb 23, 2015 8:48 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1490: "Atoms"
Replies: 92
Views: 19749

### Re: 1490: "Atoms"

I'm never quite sure to what extent Beret Guy is screwing with us and to what extent he actually has weirdly niche superpowers.
Wed Feb 04, 2015 7:31 am UTC
Forum: Mathematics
Topic: Is it possible to convert a decimal matrix into a binary mat
Replies: 7
Views: 2413

### Re: Is it possible to convert a decimal matrix into a binary

What's this for? There might be a better way to go about doing whatever it is you're trying to do.
Tue Feb 03, 2015 8:22 pm UTC
Forum: Logic Puzzles
Topic: Six statements. How many are true?
Replies: 20
Views: 7431

### Re: Six statements. How many are true?

Edit: Whoops, misread statement E as "Statement D is false if and only if statement F is false". Interestingly, the puzzle still has a unique solution, so I include it for completeness' sake. Quaanol has it right. In my modified version of the puzzle, A, B and E are true. A: "A if and...
Thu Aug 28, 2014 2:34 pm UTC
Forum: Fictional Science
Topic: "The Billiard Ball" and Non-Newtownian Drive.
Replies: 5
Views: 5848

### Re: "The Billiard Ball" and Non-Newtownian Drive.

You could set things up so it doesn't violate energy conservation, at least, by requiring a great deal (mc^2, say) of energy from the field in order to strip an object of its rest mass. Wouldn't the field actually have to gain energy rather than donate it, to balance out the loss of rest mass energ...
Mon Aug 18, 2014 10:39 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1409: "Query"
Replies: 66
Views: 21073

### Re: 1409: "Query"

It's not so bad in an SQL WHERE, and I'm not sure if it can be avoided in SQL (a bit of Googling didn't really enlighten me), but does anyone else cringe when they see "if afraidOfFlying == true"? I mean, if you really feel that a boolean expressions ought to be compared to "true&quo...
Tue Aug 12, 2014 2:49 pm UTC
Forum: Fictional Science
Topic: Time Travel Paradox
Replies: 46
Views: 14375

### Re: Time Travel Paradox

However, if you then don't receive the password, the wisest course of action for you would be to immediately turn off the machine - because *something* will act to prevent the machine from creating a paradox - and that might be as trivial as the machine breaking but could be as major as the earth b...
Tue Jul 22, 2014 12:54 pm UTC
Forum: General
Topic: ITT: We make xkcd slightly worse.
Replies: 8671
Views: 1834469

### Re: ITT: We make xkcd slightly worse.

We wanted to use the REAL temperature scale, but the tool shop didn't have any thermometers marked in Kelvin.
Spoiler:
Tue Jul 22, 2014 12:10 pm UTC
Forum: Fictional Science
Topic: items related to: roko's basilisk, boltzmann brain paradox
Replies: 53
Views: 20752

### Re: items related to: roko's basilisk, boltzmann brain parad

Don't ask me to explain it because I don't really understand it. I think his argument is that rational beings shouldn't respond to blackmail, particularly if acausal trade is on the table. If you don't respond to blackmail, the AI will know that it's pointless punishing a simulation of you to black...
Tue Jul 22, 2014 11:59 am UTC
Forum: Fictional Science
Topic: Solid Universe
Replies: 47
Views: 17028

### Re: Solid Universe

If the bubble is small, then the water molecules near its surface feel a stronger electromagnetic repulsion from the water behind them (pressure) than the amount of gravitational force they feel “repelling” them from the bubble. So water is pushed into the bubble, and the bubble shrinks. Then the b...
Tue Jul 22, 2014 11:46 am UTC
Forum: Fictional Science
Topic: Portal Ending Physics What-If (Physics/Math Heavy)
Replies: 6
Views: 5514

### Re: Portal Ending Physics What-If (Physics/Math Heavy)

Gravity doesn't pass through portals, or interact with them at all. You can see this by placing a pair of portals, one horizontal and one vertical. Objects that are near one of the portals but not actually crossing the threshold don't experience any gravitational pull from the other side. I tried to...
Sun Jul 20, 2014 12:48 am UTC
Forum: Forum Games
Topic: What is in Your Clipboard?
Replies: 3688
Views: 625983

### Re: What is in Your Clipboard?

0588521
Tue Jul 15, 2014 6:36 pm UTC
Forum: Forum Games
Topic: *almost* the best superpower in the world
Replies: 703
Views: 98139

### Re: *almost* the best superpower in the world

Reality is a lie. The truth would drive you mad.

I can turn into any animal.
Tue Jul 15, 2014 6:33 pm UTC
Forum: Forum Games
Topic: No Repeats
Replies: 174
Views: 28267

### Re: No Repeats

Jplus wrote:@snowyowl:
Spoiler:
All words in my sentence where represented by at least one letter, as requested in the game rules.

Mon Jul 14, 2014 2:01 pm UTC
Forum: Forum Games
Topic: No Repeats
Replies: 174
Views: 28267

### Re: No Repeats

Eccentric diaries are passed quickly and far in the first millennium of peace.

When you star pl id v x m b g ck.
Sat Jul 12, 2014 3:45 am UTC
Forum: Fictional Science
Topic: Solid Universe
Replies: 47
Views: 17028

### Re: Solid Universe

Well, the reason I was thinking voids would attract other voids is this: - we're imagining that there's some magic omnipresent repulsive force that exactly cancels out the gravity of a space full of normal matter. This is the only difference between the imaginary physics of the solidverse and real l...
Wed Jun 25, 2014 2:41 pm UTC
Forum: Fictional Science
Topic: items related to: roko's basilisk, boltzmann brain paradox
Replies: 53
Views: 20752

### Re: items related to: roko's basilisk, boltzmann brain parad

So, they can communicate telepathically with other people in the hive mind, but curing them of the telepathy doesn't make them think they're an individual any more?
Wed Jun 25, 2014 1:09 pm UTC
Forum: General
Topic: ITT: We make xkcd slightly worse.
Replies: 8671
Views: 1834469

### Re: ITT: We make xkcd slightly worse.

The Nobel Physics committee aren't returning my calls, but I think they're just grumpy over the giant stapler incident.
Spoiler:
Wed Jun 25, 2014 11:42 am UTC
Forum: Mathematics
Replies: 88
Views: 18573

### Re: Bad math

I like that you can solve x2 = x in the 10-adics and get four answers.

0, 1, ...212890625, and ...87109376.
Tue Jun 24, 2014 10:13 am UTC
Forum: Forum Games
Topic: You must not say duck
Replies: 8258
Views: 805005

### Re: You must not say duck

fowl
bowl
bows
rows
rocs
rock
dock
Sun Jun 22, 2014 6:30 pm UTC
Forum: Forum Games
Topic: *almost* the best superpower in the world
Replies: 703
Views: 98139

### Re: *almost* the best superpower in the world

But you can only search through them in alphabetical order. And you have to start over if you press the wrong thing. Still, you're now an expert on many situations involving aardvarks.

I can crush coal into diamonds.
Fri Jun 20, 2014 12:38 pm UTC
Forum: Fictional Science
Topic: Motivations of Aliens to Visit Earth
Replies: 135
Views: 37583

### Re: Motivations of Aliens to Visit Earth

By analogy, from 100mya, we wouldn't have necessarily predicted the rise of hominids, but things like reciprocity, memory, social hierarchy, pair-bonding, tribalism, warfare, trade, etc. those seem fairly predictable given the rise of multicellular life on a planet with sufficient ecological comple...
Fri Jun 20, 2014 12:10 pm UTC
Forum: Forum Games
Topic: Word disassociation
Replies: 127
Views: 19111

### Re: Word disassociation

I'm sorry, but the Rain Song by Led Zeppelin has a keyboard play the accompaniment.

Thu Jun 19, 2014 6:25 am UTC
Forum: Fictional Science
Topic: items related to: roko's basilisk, boltzmann brain paradox
Replies: 53
Views: 20752

### Re: items related to: roko's basilisk, boltzmann brain parad

After thinking about it some more I can really appreciate the irony of a bunch of distinctly atheistic people basically inventing hell. It's not exactly the same thing of course, but the concept "Support our god or you will be tortured for all eternity after your death" is very similar. S...
Sat Jun 14, 2014 5:13 pm UTC
Forum: Fictional Science
Topic: Planet-sized robot
Replies: 25
Views: 7918

### Re: Planet-sized robot

Whoa. One more for the "impractical" column, I think.
Sat Jun 14, 2014 4:32 pm UTC
Forum: Fictional Science
Topic: Planet-sized robot
Replies: 25
Views: 7918

### Re: Planet-sized robot

Don't get me wrong; it's a great idea. Balancing gravitational force with elective electrostatic repulsion so that the forces are manageable wherever you need mobility and normal wherever you can allow regular compression. The whole thing is going to create one hell of a strong external electrostat...
Fri Jun 13, 2014 8:21 am UTC
Forum: Fictional Science
Topic: Planet-sized robot
Replies: 25
Views: 7918

### Re: Planet-sized robot

stoppedcaring wrote:Well, each individual component will have to be completely insulated from static discharge, or the charge will collect on the outside and the inside will collapse.

Damn it, that's a good point.
Thu Jun 12, 2014 4:02 pm UTC
Forum: Forum Games
Topic: Invent an emoticon
Replies: 50
Views: 6004

### Re: Invent an emoticon

Kanye West glasses.

q('_')p
Thu Jun 12, 2014 12:31 pm UTC
Forum: What If?
Topic: What-if 0094: "Billion-Story Building"
Replies: 106
Views: 28120

### Re: What-if #0094: Billion-Story Building

brenok wrote:No, that'd be a Kilo skyscraper. A Mega skyscraper would be 1000000 skyscrapers. I brought this important issue up here

But a skyscraper that's 100 times taller, 100 times wider, and 100 times broader, is actually a mega-skyscraper.
Thu Jun 12, 2014 11:42 am UTC
Forum: Forum Games
Topic: *almost* the best superpower in the world
Replies: 703
Views: 98139

### Re: *almost* the best superpower in the world

But if you stop for more than five minutes, you die.

(How is that even a superpower?)

I don't age.
Thu Jun 12, 2014 11:38 am UTC
Forum: General
Topic: ITT: We make xkcd slightly worse.
Replies: 8671
Views: 1834469

### Re: ITT: We make xkcd slightly worse.

teelo wrote:I don't understand the problem of Global Warming. We can just drop a giant ice cube in the ocean every now and then, thus solving the problem once and for all.

Last time we tried that, it sunk the Titanic.
Thu Jun 12, 2014 10:56 am UTC
Forum: Fictional Science
Topic: Planet-sized robot
Replies: 25
Views: 7918

### Re: Planet-sized robot

Electric and magnetic fields or no, the components will still end up having to lift themselves against the net gravity of the whole, Not so! If you simply give the entire structure an electrical charge of... um... [scribble scribble wolframalpha scribble] 86 picocoulombs per gram, then the electric...
Thu Jun 12, 2014 10:13 am UTC
Forum: Fictional Science
Topic: Hard sci fi and the tyranny of the rocket equation
Replies: 53
Views: 13884

### Re: Hard sci fi and the tyranny of the rocket equation

What happens if you activate the gravity rail while moving vertically? It could make you stop, but where do your kinetic energy and momentum go? I would assume that the object would rise and fall as appropriate to maintain the same energy state. More extreme example: Drop the machine to the bottom o...
Wed Jun 11, 2014 11:22 am UTC
Forum: Fictional Science
Topic: Planet-sized robot
Replies: 25
Views: 7918

### Re: Planet-sized robot

First, a disclaimer: Giant robots are impractical in every possible way. However, they look really damn cool, and so we don't question them too hard. I think, to build something like this, I'd completely forget about structural integrity. There's no material in the universe strong enough. If you tri...
Wed Jun 11, 2014 7:48 am UTC
Forum: Individual XKCD Comic Threads
Topic: 1380: "Manual for Civilization"
Replies: 107
Views: 21010

### Re: 1380: "Manual for Civilization"

Silhalnor wrote:Does this happen for everyone? The first time you feel the urge to post you find that you already have a ready made account and password waiting for you?

That's how it works on Trollian.

Go to advanced search