## Search found 2439 matches

Mon May 07, 2012 10:31 pm UTC
Forum: News & Articles
Topic: Bill Nye booed in Waco, said moon doesn't generate light
Replies: 65
Views: 15182

### Re: Bill Nye booed in Waco, said moon doesn't generate light

A miracle can duplicate any cleric spell of 7th level or greater, including resurrection, which as we all know can restore life to an undead creature that was subsequently destroyed, so I would say a miracle is exactly what was called for here.
Sun May 06, 2012 3:25 am UTC
Forum: Mathematics
Topic: Number of non-isomorphic directed graphs
Replies: 1
Views: 980

### Re: Number of non-isomorphic directed graphs

A000273 in OEIS

There is no closed-form expression, but some algorithms using Polya enumeration are provided in OEIS.
Sat May 05, 2012 1:23 am UTC
Forum: News & Articles
Topic: It's official, Hollywood is fucking with us
Replies: 120
Views: 18497

### Re: It's official, Hollywood is fucking with us

I would like to second the a Magic the Gathering movie having potential - A lot of their fiction is terrible, but a lot (particularly the ice-age era comics, imo, though the Arena and Gull&Greensleeves stories were decent too) was pretty damn good. I want a movie entitled "Urza's Madness&q...
Thu Apr 26, 2012 3:22 pm UTC
Forum: Mathematics
Topic: Minimizing Surface Area of a piece of bread
Replies: 8
Views: 2772

### Re: Minimizing Surface Area of a piece of bread

Cut your slice, then put it in an impermeable bag and close it. This artificially reduces the surface area.

If that isn't an option, I'm pretty sure you do best by just making one slice straight across the bread, though I don't exactly have an elegant proof.
Wed Apr 25, 2012 12:35 am UTC
Forum: Mathematics
Topic: Cannot understand some mathematical notation/symbols.
Replies: 6
Views: 2620

### Re: Cannot understand some mathematical notation/symbols.

Yes, that is a correct formula for N choose k (as long as N and k are nonnegative integers).
Tue Apr 24, 2012 10:06 pm UTC
Forum: Mathematics
Topic: Looking for a graph algorithm
Replies: 11
Views: 3648

### Re: Looking for a graph algorithm

That looks good to me. If G has a Hamiltonian cycle, and G has more than 2 vertices, then we get to find a solution to DrZiro's problem on G' that crosses out Pn + n(n-2) elements, where P is the size of the punishment sets. If G has no Hamiltonian cycle, then we can't.
Tue Apr 24, 2012 9:26 pm UTC
Forum: Mathematics
Topic: Looking for a graph algorithm
Replies: 11
Views: 3648

### Re: Looking for a graph algorithm

Oh, I see. I guess I misunderstood the problem. I thought you were required to select the edges from some pre-existing digraph, but I guess that's a more general problem than you wanted to solve. You're just asking about the case where G is complete.
Mon Apr 23, 2012 3:22 pm UTC
Forum: News & Articles
Topic: French Presidential Election 2012
Replies: 67
Views: 13111

### Re: French Presidential Election 2012

From way over here in the US, I can't really differentiate between Sarkozy and Hollande. But I can tell that Le Pen is insane. If 20% of people are voting for her, for any reason, you have a problem brewing, which you need to do something about. Otherwise you could become like us.
Mon Apr 23, 2012 3:57 am UTC
Forum: Mathematics
Topic: Looking for a graph algorithm
Replies: 11
Views: 3648

### Re: Looking for a graph algorithm

DrZiro wrote:++\$_, that proof looks promising. I'll have to think about it some more.
Although since each set has n-1 elements, I think each edge would allow you to cross out n-2, right? So the hamiltonian cycle gives n(n-2) crossed out elements.
Uh, yeah, that's right. Whoops.
Sun Apr 22, 2012 9:19 pm UTC
Forum: Mathematics
Topic: Showing that a group ISN'T a subgroup of another
Replies: 6
Views: 2197

### Re: Showing that a group ISN'T a subgroup of another

Do you know the order of both groups? For example if |G| and |H| are relatively prime, then G is not a subgroup of H and H is not one of G (if I recall correctly) That is correct (in fact, in that case G and H have no isomorphic nontrivial subgroups), but since he is worried about the existence of ...
Sun Apr 22, 2012 7:48 pm UTC
Forum: Mathematics
Topic: Need help proving a variation on the halting problem
Replies: 2
Views: 1414

### Re: Need help proving a variation on the halting problem

I don't know where (or if) this appears in the literature, but unless I'm missing something, I think the proof is straightforward. Suppose, for purposes of contradiction, that you have an oracle that can solve your problem for a collection of n Turing machines. We will show, by induction, that we ca...
Sun Apr 22, 2012 2:25 am UTC
Forum: Mathematics
Topic: Looking for a graph algorithm
Replies: 11
Views: 3648

### Re: Looking for a graph algorithm

Oh, right, you are limited to one outgoing edge per vertex. So you're right, there is always a cycle if you include the full number of edges. In that case, I'm pretty sure the problem is NP-complete (whether or not including the full number of edges is mandatory). Proof: Let G be a digraph on {1, .....
Sat Apr 21, 2012 6:12 am UTC
Forum: Gaming
Topic: What makes for good turn-based combat?
Replies: 46
Views: 15723

### Re: What makes for good turn-based combat?

A variation on decaying attack strength is to make each ability cost more resources the more frequently you do it. Of course the amount required would go back down to the minimum if you left the ability unused for a while. One way to ensure that every ability gets used is to make the resource cost a...
Sat Apr 21, 2012 5:48 am UTC
Forum: Mathematics
Topic: Looking for a graph algorithm
Replies: 11
Views: 3648

### Re: Looking for a graph algorithm

When you say "From each node, we can place one outgoing edge," do you mean that each node must have an outgoing edge? If so, then any solution you create will necessarily have a cycle. Even if it's not mandatory, I can't see how adding an outgoing edge to a vertex that doesn't have one wo...
Fri Apr 20, 2012 2:46 am UTC
Forum: Gaming
Topic: Magic : The Gathering : The Thread : The Rename
Replies: 1691
Views: 293041

### Re: Magic : The Gathering : The Thread : The Rename

There's some confusion going on. Temporal Manipulation is best played with Brainstorm (also FoW, as mosc correctly points out). But some people are trying to play it with Personal Tutor. That is not good, because you are spending 1UU and two cards for an extra turn. With Brainstorm, you are spending...
Fri Apr 20, 2012 1:22 am UTC
Forum: News & Articles
Topic: Asteroid mining is here?
Replies: 66
Views: 11602

### Re: Asteroid mining is here?

If asteroids were made out of iridium then it would probably be worth mining them. However, it turns out that asteroids are made out of rock. (Yes, a few of them are made out of metal, but the situation isn't terribly different.) I don't know the exact numbers, but I expect your average scrapyard ha...
Tue Apr 17, 2012 6:48 am UTC
Topic: Are we on the brink of passing the Turing test?
Replies: 71
Views: 14623

### Re: Are we on the brink of passing the Turing test?

Computers are going to have extremely useful AI way before they are capable of reliably passing the Turing Test. To pass that you have to be able to fake personality and emotion - eg keep repeating the same question to the average person and they'll get annoyed. Computers will show far more patienc...
Sun Apr 15, 2012 1:33 am UTC
Forum: Mathematics
Topic: Probability - Hashing
Replies: 9
Views: 2395

### Re: Probability - Hashing

It is not possible even in theory. An MD5 hash is not an encoding of a movie. It is merely a signature. There are 2 8,000,000,000 different 1-gigabyte movies. There are 2 128 different MD5 hashes. This means that there are 2 7,999,999,872 different movies for each hash. There is absolutely no way to...
Thu Apr 12, 2012 3:02 am UTC
Topic: Asexuality
Replies: 330
Views: 73093

### Re: Asexuality

I've read several people discuss the difficulty in having a relationship while being asexual. In my mind, that sounds like a friendship. Someone you could count on, who is there for you when the going gets tough, etc. I think most people have some friends - maybe even deeply committed, lifelong fri...
Wed Apr 11, 2012 10:00 pm UTC
Forum: Mathematics
Topic: Favorite math jokes
Replies: 1452
Views: 478264

### Re: Favorite math jokes

Monika wrote:Hm, explain?
It's the Fourier transformer.
Wed Apr 11, 2012 12:20 am UTC
Forum: News & Articles
Topic: U.S. Republican Primary
Replies: 2855
Views: 291657

### Re: U.S. Republican Primary

Poe's Law; sarcasm on the internet has a chance to be taken seriously equal to the percentage of serious arguments in the topic. Poe's Strong Law; if a conversation goes on long enough, Poe's Law will eventually be triggered. Poe-Godwin Law; if Poe's Law is discussed for at length, eventually Godwi...
Mon Apr 09, 2012 3:05 am UTC
Forum: Science
Topic: Amoeba visible to the naked eye
Replies: 7
Views: 9467

### Re: Amoeba visible to the naked eye

Most amoebas live in murky water and are translucent to transparent. As a result, you can't see them when they're in their natural habitat, especially if you don't want to stick your nose in the pond. If you want to see them you'd better take a sample of the water and look at it with backlight. It's...
Fri Apr 06, 2012 3:43 pm UTC
Forum: Science
Topic: Cen-something-al Force...or is it?
Replies: 20
Views: 4105

### Re: Cen-something-al Force...or is it?

King Author wrote:Whoa whoa whoa, what? Gravity is directed toward the center of the circle? Surely it's constantly directed toward the Earth?
I was talking only about the situation at the top of the circle, where the gravitational force does happen to be pointing towards the center of the circle.
Fri Apr 06, 2012 2:01 am UTC
Forum: Science
Topic: Cen-something-al Force...or is it?
Replies: 20
Views: 4105

### Re: Cen-something-al Force...or is it?

Look at the situation where the bucket is directly over your head. If there were no force on the water, it would move in a straight line at constant velocity forever. But instead, it's moving in a circle. Why? Because there is a force pushing it towards the center of the circle. "No," you ...
Wed Apr 04, 2012 12:09 pm UTC
Forum: Mathematics
Topic: Integral help
Replies: 11
Views: 4108

### Re: Integral help

Your last line has an error (it should be u-1/2). It's strongly advised that you now put v = sqrt(u).

One way to integrate log(x) is by parts. One part is log(x). The other part is dx.
Wed Apr 04, 2012 12:07 pm UTC
Forum: News & Articles
Topic: Arizona outlaws trolling
Replies: 59
Views: 8446

### Re: Arizona outlaws trolling

The interpretations I've seen say that this is not actually intended to ban trolling (obviously), or strongly worded blog posts, or whatever. They're trying to update laws that would make it a crime to make harassing phone calls. The only problem is that because they've never used the technology the...
Wed Apr 04, 2012 5:10 am UTC
Topic: Asexuality
Replies: 330
Views: 73093

### Re: Asexuality

Do they not realize that so many the things they say were (and still are) said word-for-word about gay people? Like, I don't even have to change any of the words. "You just haven't met the right girl/guy yet." "You must have had a bad experience." "It's just a phase. You'll ...
Wed Apr 04, 2012 4:53 am UTC
Topic: Asexuality
Replies: 330
Views: 73093

### Re: Asexuality

Oh. My. God. The comments in that Dan Savage article (linked in the Atlantic) are horrible. (I realize this is like 3 levels removed but they were referenced in the article.) And presumably those are mostly people who identify or empathize with a marginalized minority and should know better. I am li...
Wed Apr 04, 2012 2:35 am UTC
Forum: Mathematics
Topic: Integral help
Replies: 11
Views: 4108

### Re: Integral help

You can't integrate 1/(u^2-1)?

Try partial fractions. (Yes, you could also do it with hyperbolic trigonometric functions, but that will just get you the same answer in a more obscure form.)
Wed Apr 04, 2012 2:25 am UTC
Forum: Mathematics
Topic: Integral help
Replies: 11
Views: 4108

### Re: Integral help

If you want to do u2/(u2-1), just add and subtract 1 from the numerator to get 1 + 1/(u2-1). That you should know how to do.
Wed Apr 04, 2012 2:21 am UTC
Forum: News & Articles
Topic: Arizona outlaws trolling
Replies: 59
Views: 8446

### Re: Arizona outlaws trolling

Ken from Popehat has a pretty good response.
Wed Apr 04, 2012 2:19 am UTC
Forum: Mathematics
Topic: Integral help
Replies: 11
Views: 4108

### Re: Integral help

I started with u = sqrt(1+ex).

That got me to (1/2)log(u2-1) (unless I messed up). That should be doable. (Just factor u2-1).
Wed Apr 04, 2012 1:34 am UTC
Forum: Mathematics
Topic: Analysis - limits and integrals
Replies: 8
Views: 2069

### Re: Analysis - limits and integrals

It says: "R(x) is a rational function with the degree of the numerator greater or equal to the degree of the denominator + 2."
Sun Apr 01, 2012 7:24 pm UTC
Forum: Mathematics
Topic: Anyone got a handy proof that a^((p-1)(q-1)) = 1 mod pq ?
Replies: 4
Views: 2284

### Re: Anyone got a handy proof that a^((p-1)(q-1)) = 1 mod pq

I would suggest that eu euse Eulers Theorem. What is phi(pq)?
Sat Mar 31, 2012 4:04 am UTC
Forum: News & Articles
Topic: No more pennies, at least in Canada
Replies: 102
Views: 13543

### Re: No more pennies, at least in Canada

Yeah, I guess nonmagnetized (but ferromagnetic) coins and magnetized coins shouldn't be mixed. If you only have magnetized coins, though, you should be able to just take a column of coins from your pocket like you might take a wallet and peel a few off. In my head this is extremely awesome, at least...
Sat Mar 31, 2012 3:37 am UTC
Forum: News & Articles
Topic: No more pennies, at least in Canada
Replies: 102
Views: 13543

### Re: No more pennies, at least in Canada

But if the coins themselves were magnetic, they would stick together in a more orderly fashion, right? In my experience disk-shaped magnets line themselves up into columns.

(Also, you have ferromagnetic coins in Canada? Weird.)
Sat Mar 31, 2012 3:12 am UTC
Forum: News & Articles
Topic: No more pennies, at least in Canada
Replies: 102
Views: 13543

### Re: No more pennies, at least in Canada

All coins are dangerous for young children to eat in a purely mechanical sense. Toxicity is the least of your worries.
Sat Mar 31, 2012 3:10 am UTC
Forum: Mathematics
Topic: Favorite math jokes
Replies: 1452
Views: 478264

### Re: Favorite math jokes

A long time ago, far away from any other civilization, there was a little house between two hills, and in the house there lived a farmer, his wife, and his young daughter. Now, because the hills were so far away from civilization, they had no official names, so the family just called them Hill One a...
Sat Mar 31, 2012 2:46 am UTC
Forum: News & Articles
Topic: No more pennies, at least in Canada
Replies: 102
Views: 13543

### Re: No more pennies, at least in Canada

Maybe they should make dollar coins with holes in the middle. Then we can easily put them on strings or rods, (mostly) solving the problem of it being awkward to carry them around. Alternatively, magnetize them so that they stick together in columns all by themselves. This may be slightly incompatib...
Fri Mar 30, 2012 8:19 pm UTC
Forum: News & Articles
Topic: No more pennies, at least in Canada
Replies: 102
Views: 13543

### Re: No more pennies, at least in Canada

Sure. But we don't need dollar bills, dollar coins are just fine. I disagree. Bills fit nicely into a wallet. Coins do not. I try to get rid of my dollar coins whenever I can because they are a total pain to use. To put it another way, if I have \$10 in \$1 bills in my pocket, I have one object in my...