## Search found 319 matches

Sun Feb 12, 2012 7:18 am UTC
Forum: Religious Wars
Topic: Chess vs. Go Which is the better board game.
Replies: 55
Views: 27992

### Re: Chess vs. Go Which is the better board game.

In Chess Life a few decades ago, a checker player played against a chess player; each set up their half of the board with their pieces and played by their rules. The checker player won, although the chess player has an unbeatable strategy.
Sat Feb 11, 2012 8:20 am UTC
Forum: Mathematics
Topic: Largest 3 consecutive semi-primes?
Replies: 19
Views: 5721

### Re: Largest 3 consecutive semi-primes?

tomtom2357 wrote:That is probably about as difficult as the twin prime problem, which has not been solved yet.

A new milestone has been reached, though: Terrence Tao recently proved that every odd number is the sum of at most five primes.
Sat Feb 11, 2012 8:10 am UTC
Forum: Science
Topic: Formula for lunar phase?
Replies: 2
Views: 8610

### Re: Formula for lunar phase?

If you're only interested in the day, a few simple algorithms are available at http://www.ben-daglish.net/moon.shtml A NASA website says: Algorithms used in predicting the phases of the Moon as well as eclipses are based on Jean Meeus' Astronomical Algorithms (Willmann-Bell, Inc., Richmond, 1998). Y...
Fri Feb 10, 2012 7:45 am UTC
Forum: Mathematics
Topic: help with diophantine approximation.
Replies: 39
Views: 5815

### Re: help with diophantine approximation.

Have you tried solving simpler problems, like maximizing

min ( <a><b>, 2<2a><2b> )
min ( <a><b>, 2<2a><2b>, 3<3a><3b> )
...

?

(I'm using <a> for your ||a||, since ||a||||b|| is nasty on the eyes ...)
Thu Feb 09, 2012 7:19 am UTC
Topic: Insult Generator
Replies: 19
Views: 10676

### Re: Insult Generator

Are you always thinking of the right comeback twenty minutes too late? Do people always make fun of your duck in hoi sin sauce wrap or dole cheque? Well for quick, effective comebacks look no further... introducing: THE INSULT GENERATOR!!! Nice stupid algorithm , you lazy bastard . Mad-libs are not...
Mon Feb 06, 2012 6:01 am UTC
Forum: Mathematics
Topic: A Probability Conundrum
Replies: 7
Views: 1258

### Re: A Probability Conundrum

The mean sum is easy ... you take the expected value and multiply it by the number of cards: \left(1 \cdot {12\over56} + 2\cdot{8\over 56} + 3 \cdot {8\over 56} + \cdots + 6\cdot {8\over 56} + 7 \cdot {4\over 56}\right)\cdot 5 which is 125/7 (checked with Maple). (This works because I'm usin...
Sat Feb 04, 2012 6:58 am UTC
Forum: Logic Puzzles
Topic: Overhanging dominoes
Replies: 9
Views: 4649

### Re: Overhanging dominoes

Which brings us to our next problem: for each positive integer N, using exactly N tiles, what is the greatest amount of overhang that can be realized? That is, the single tile that overhangs the most, its amount of overhang is to be maximized among all stable arrangements of N tiles. A couple of ye...
Wed Feb 01, 2012 6:26 am UTC
Forum: Science
Topic: How can I obtain hard-to-get papers?
Replies: 14
Views: 2279

### Re: How can I obtain hard-to-get papers?

To the OP: If you post the journals you're looking for, you'll probably get lots of help.
Wed Feb 01, 2012 6:24 am UTC
Forum: Mathematics
Topic: An interesting probability problem that I thought of
Replies: 5
Views: 1191

### Re: An interesting probability problem that I thought of

314man wrote:The trend continues to be n / (n+1)!

Digression: There's a classical problem where you have to show that
${1\over 2!} + {2 \over 3!} + {3 \over 4!} + \cdots + {n-1 \over n!} = 1 - {1\over n!},$
which is usually done by induction. This is another proof of the same result.
Tue Jan 31, 2012 7:15 am UTC
Forum: Gaming
Topic: Games you have programmed
Replies: 93
Views: 36869

### Re: Games you have programmed

Dason wrote:Eh - I don't really care too much. I just thought you might want to update the link in case you were going to share that with other people.

Actually, I did that too. Thanks.
Tue Jan 31, 2012 7:09 am UTC
Forum: Religious Wars
Replies: 81
Views: 47107

First OS: Er ... what did the Timex/Sinclair 1000 run on?
Spoiler:
According to Wikipedia ... Sinclair BASIC

Okay, maybe that one doesn't count. Next OS: DOS 3.3 (Apple IIc)
Mon Jan 30, 2012 7:42 am UTC
Forum: Computer Science
Topic: Regular Expression for the following language
Replies: 6
Views: 2208

### Re: Regular Expression for the following language

((a|b|c|d)*a(a|b|c|d)*a(a|b|c|d)*c(a|b|c|d)*c(a|b|c|d)*c(a|b|c|d)*c(a|b|c|d)*|...) (where "..." means "and done similarly for all other ordings of aacccc"), i.e., brute force, works but looks very messy.
Mon Jan 30, 2012 7:29 am UTC
Forum: Gaming
Topic: Games you have programmed
Replies: 93
Views: 36869

### Re: Games you have programmed

A one-player version of Kensington (which probably violates all sorts of copyright laws) ... http://www.public.asu.edu/~checkma/Kensington/ The AI isn't too good; I've tried to do the programming in Javascript. The link to the rules seems to be broken. Oh. Use the Wayback Machine then: http://web.a...
Mon Jan 30, 2012 7:23 am UTC
Forum: Science
Topic: Astrology
Replies: 9
Views: 2111

### Re: Astrology

I can never find my horoscope in the paper. You see, I'm a Cetus (the Whale).
Sun Jan 29, 2012 7:25 am UTC
Forum: Mathematics
Topic: Favourite Erroneous "Proofs"
Replies: 194
Views: 41365

### Re: Favourite Erroneous "Proofs"

AFAIK, this one is new:

-1 = det [-1] = | -1 | = abs(-1) = 1.

"Proof by confusion of notation."
Sun Jan 29, 2012 7:21 am UTC
Forum: Religious Wars
Topic: Chess vs. Go Which is the better board game.
Replies: 55
Views: 27992

### Re: Chess vs. Go Which is the better board game.

I couldn't get past the rules for determining who wins a game ... Placing captured pieces in open areas and counting? Really?

Of course, I learned Chess first ...
Sun Jan 29, 2012 7:19 am UTC
Forum: Gaming
Topic: Games you have programmed
Replies: 93
Views: 36869

### Re: Games you have programmed

A one-player version of Kensington (which probably violates all sorts of copyright laws) ... http://www.public.asu.edu/~checkma/Kensington/ The AI isn't too good; I've tried to do the programming in Javascript. I wrote a Win32 version of "Subway Shuffle". I had communicated with the author...
Sat Jan 28, 2012 7:47 am UTC
Forum: Religious Wars
Topic: Chess vs. Go Which is the better board game.
Replies: 55
Views: 27992

### Re: Chess vs. Go Which is the better board game.

What do you mean by "better"? BTW, in the 1980s, a lot of difficult Go positions were analyzed using Combinatorial Game Theory ... look for a book called Mathematical Go Endgames: Nightmares for the Professional Go Player by Berlecamp and Wolfe if you want the details. You might have bett...
Sat Jan 28, 2012 7:46 am UTC
Forum: Religious Wars
Topic: Chess vs. Go Which is the better board game.
Replies: 55
Views: 27992

### Re: Chess vs. Go Which is the better board game.

What do you mean by "better"?

BTW, in the 1980s, a lot of difficult Go positions were analyzed using Combinatorial Game Theory ... look for a book called Mathematical Go Endgames: Nightmares for the Professional Go Player by Berlecamp and Wolfe if you want the details.
Fri Jan 27, 2012 4:58 am UTC
Forum: News & Articles
Topic: Obama attacks, defends bailouts.
Replies: 46
Views: 4793

### Re: Obama attacks, defends bailouts.

Anyways, I don't think it's just racism that effects ridiculous criticism of Obama. I myself am too young to remember the Clinton administration in any useful detail, but my dad tells me that there was about as much ridiculous partisanship and obstructionism then. I mean hell, they impeached Clinto...
Thu Jan 26, 2012 7:14 am UTC
Forum: News & Articles
Topic: Obama attacks, defends bailouts.
Replies: 46
Views: 4793

### Re: Obama attacks, defends bailouts.

Iulus Cofield wrote:Here we go. I'll get the the milk duds and root beer.

Are you in your comfortable chair as well?
Thu Jan 26, 2012 7:11 am UTC
Forum: Mathematics
Topic: Set-theoretic brain fart
Replies: 9
Views: 2019

### Re: Set-theoretic brain fart

In my amateur opinion, I don't think the "large" in "large cardinal" means what you think it means. I mean, you already know that size is relative, so in some sense it can't. Besides, in any model of ZFC, the cardinals already go all the way up to the top. I don't believe that's...
Tue Jan 24, 2012 6:49 am UTC
Forum: General
Topic: Anyone know what this font is?
Replies: 8
Views: 1587

### Re: Anyone know what this font is?

What can I say? I'm a font freak! (And that's a useful website, even though this might be only the second time I've used it.)
Tue Jan 24, 2012 6:35 am UTC
Topic: New (old) anti-piracy threats -- ACTA etc.
Replies: 10
Views: 8165

### Re: A new (old) threat

According to ACTA, the person being charged with copyright violation would have to prove that their material does not violate copyright. This is the exact opposite of the rights guaranteed by the Bill of Rights (due process, "innocent until proven guilty", etc.). It is NOT constitutional....
Tue Jan 24, 2012 6:30 am UTC
Forum: Computer Science
Topic: Ugh... fiendish CS proffs...
Replies: 26
Views: 4520

### Re: Ugh... fiendish CS proffs...

jareds wrote:As originally posed, the problem is in Scheme, which has exact rationals.

Oh. Well, I was confused by the C code.
Tue Jan 24, 2012 6:07 am UTC
Topic: 1007: "Sustainable"
Replies: 115
Views: 27967

### Re: 1007: "Sustainable"

zugy wrote:Google was unusually popular around the 1900's. I suspected it was recaptcha typos of googol, however a quick search and scanning of the results makes me suspect otherwise. Smells like recaptcha shenanigans to me!

Nope. The word "googol" was coined in 1929.
Tue Jan 24, 2012 6:04 am UTC
Forum: General
Topic: Anyone know what this font is?
Replies: 8
Views: 1587

### Re: Anyone know what this font is?

http://new.myfonts.com/WhatTheFont/ says that the name of the font is Confidential. (That's its name; it's not a confidential name.)

See http://new.myfonts.com/fonts/fontfont/f ... fidential/
Mon Jan 23, 2012 6:56 am UTC
Topic: New (old) anti-piracy threats -- ACTA etc.
Replies: 10
Views: 8165

### Re: A new (old) threat

Could you add ACTA to the thread title? Thanks. I didn't really know what it was but heard it mentioned in the course of SOPA/PIPA discussions, and I've just started branching out to finding out other bullshit going on. I just looked around and I found one video from 2009 that explains why ACTA (An...
Mon Jan 23, 2012 6:47 am UTC
Topic: 1007: "Sustainable"
Replies: 115
Views: 27967

### Re: 1007: "Sustainable"

Did anyone else notice the levelling off between 2000 and 2008? Gee, it's almost as if ...
Mon Jan 23, 2012 2:14 am UTC
Forum: Computer Science
Topic: Ugh... fiendish CS proffs...
Replies: 26
Views: 4520

### Re: Ugh... fiendish CS proffs...

There's another nuance to this problem ... Since computers can't express 1/3 exactly (with floating point), [3, 1, 1/3] wouldn't turn out to be a geometric series, since 3 * (1/3) is highly unlikely to equal 1 exactly.
Mon Jan 23, 2012 2:03 am UTC
Forum: Mathematics
Topic: A maths question is giving me some difficulty...
Replies: 12
Views: 2357

### Re: A maths question is giving me some difficulty...

Does your helper get to share the Prize of Great Worth?
Fri Jan 20, 2012 7:21 am UTC
Forum: Mathematics
Replies: 6
Views: 2404

I don't shave when I shower. I'd get electrocuted.
Fri Jan 20, 2012 7:19 am UTC
Forum: Computer Science
Topic: Ugh... fiendish CS proffs...
Replies: 26
Views: 4520

### Re: Ugh... fiendish CS proffs...

Also, letterX's code crashes for the sequence [0, 0, 0, 0, ...]
Thu Jan 19, 2012 6:35 am UTC
Forum: Computer Science
Topic: Pattern analysis
Replies: 5
Views: 2016

### Re: Pattern analysis

Re-reading your original question, it looks like you are more interested in the "magic happens" step here of determining this simplest Turing machine (or some other representation of an algorithm) that would output the sequence. One (again theoretical) way would be to enumerate all Turing...
Tue Jan 17, 2012 5:04 am UTC
Forum: Religious Wars
Topic: The Rise and Fall of Programming Languages in 2011
Replies: 20
Views: 8885

### Re: The Rise and Fall of Programming Languages in 2011

Interesting that C++ took a nosedive around 2005 ... That was about when some of the standards were changed (including the addition of namespaces). Um, no? The first standard was published in 1998 (including namespaces), and the second in 2011. There was a revision around 2003 but those were only m...
Tue Jan 17, 2012 5:00 am UTC
Forum: Mathematics
Topic: Nonstandard proofs for simple theorems
Replies: 34
Views: 6628

### Re: Nonstandard proofs for simple theorems

(I assume that other theorem are allowed here.)

How about Fürstenberg's proof of the infinitude of primes?

http://en.wikipedia.org/wiki/F%C3%BCrst ... _of_primes

(or http://www.cut-the-knot.org/proofs/Furstenberg.shtml , since Wikipedia is going away in a day or so.)
Mon Jan 16, 2012 4:27 am UTC
Forum: Computer Science
Topic: Mind Blowing Algorithms
Replies: 76
Views: 27203

### Re: Mind Blowing Algorithms

I saw the following code online for the number of 1s. Haven't tested it. /* count number of 1's in 9-bit argument (Schroeppel) */ unsigned count_ones(unsigned36 a) { return ((a * 01001001001) /* 4 adjacent copies */ & 042104210421) /* every 4th bit */ % 15; /* casting out 15.'s in hexadecimal */...
Mon Jan 16, 2012 4:22 am UTC
Forum: Religious Wars
Topic: The Rise and Fall of Programming Languages in 2011
Replies: 20
Views: 8885

### Re: The Rise and Fall of Programming Languages in 2011

Interesting that C++ took a nosedive around 2005 ... That was about when some of the standards were changed (including the addition of namespaces). Um, no? The first standard was published in 1998 (including namespaces), and the second in 2011. There was a revision around 2003 but those were only m...
Mon Jan 16, 2012 4:13 am UTC
Forum: Mathematics
Topic: New types of numbers
Replies: 38
Views: 6266

### Re: New types of numbers

Gaps? I thought [ the surreals ] were the largest possible ordered field. How can you have gaps in that? For example, there is a "gap" between the finite surreals (surreals bounded by two real numbers) and the positive infiinite surreals. Or, for example, between the surreals smaller than...
Sat Jan 14, 2012 8:44 pm UTC
Forum: Religious Wars
Topic: The Rise and Fall of Programming Languages in 2011
Replies: 20
Views: 8885

### Re: The Rise and Fall of Programming Languages in 2011

Interesting that C++ took a nosedive around 2005 ... That was about when some of the standards were changed (including the addition of namespaces). And I'm surprised that Perl isn't more popular; it's powerful because every algorithm has been programmed in it. About the only thing missing is: print ...