## Search found 218 matches

- Tue Nov 22, 2011 2:28 am UTC
- Forum: Mathematics
- Topic: Math Books
- Replies:
**379** - Views:
**273957**

### Re: Math Books

I'm looking for a good book on number theory that is approachable to someone who took calculus and linear algebra 6 years ago, forgot most of it, and hasn't really studied anything math related since them I think "A Friendly Introduction to Number Theory" by Silverman might be a good plac...

- Sun Oct 09, 2011 4:23 am UTC
- Forum: Mathematics
- Topic: Does category theory have any real world applications?
- Replies:
**5** - Views:
**2092**

### Re: Does category theory have any real world applications?

Yep. Some of the cutting edge algorithms in linguistics, I think in automated translation more precisely, now use category theory.

I don't know the details because I've never studied linguistics, but several friends of mine worked in that field, so that's where I gleaned the info.

I don't know the details because I've never studied linguistics, but several friends of mine worked in that field, so that's where I gleaned the info.

- Tue Sep 13, 2011 4:32 am UTC
- Forum: Mathematics
- Topic: Help with proofs!!
- Replies:
**9** - Views:
**1492**

### Re: Help with proofs!!

2 hours is not excessive for a hard problem from my experience; most assignments I've been given contains at least one such question. If every single problem assigned is taking you 2 hours, and there's lots of problems assigned, then that would be a warning sign. At the end of the day, make sure it'...

- Sat Jun 18, 2011 6:17 am UTC
- Forum: Mathematics
- Topic: This is what bothers me about predicate logic
- Replies:
**15** - Views:
**3691**

### Re: This is what bothers me about predicate logic

So if variables in predicate logic represent relations then what do predicate logic formulas with only one variable represent. Variables in predicate logic do not represent relations. Relations represent relations. First order logic is termed a logic of relations because it's based on the notion of...

- Wed Jun 15, 2011 11:41 pm UTC
- Forum: Mathematics
- Topic: This is what bothers me about predicate logic
- Replies:
**15** - Views:
**3691**

### Re: This is what bothers me about predicate logic

To make things simple lets just say a variable represents one word. You can use predicate logic to "translate" natural languages into logic. Yes, this is very hard to define because natural languages are tricky things. Welcome to computational linguistics. You can use predicate logic to M...

- Mon Jun 13, 2011 12:14 am UTC
- Forum: Mathematics
- Topic: PhD in hand
- Replies:
**43** - Views:
**6106**

### Re: PhD in hand

skeptical scientist wrote:I'm doing a postdoc in New Zealand.

Nice! I met some people from there in logic. They have a strong program there from what they said. Will you continue to do work in logic?

- Sun Jun 12, 2011 9:28 am UTC
- Forum: Mathematics
- Topic: PhD in hand
- Replies:
**43** - Views:
**6106**

### Re: PhD in hand

Woooo! Congrats! Party time! ^^

- Sun May 15, 2011 4:05 pm UTC
- Forum: Mathematics
- Topic: Math Books
- Replies:
**379** - Views:
**273957**

### Re: Math Books

Kolmogorov wrote a three-volume book with Aleksandrov and Lavrent'ev, where they especially emphasize Soviet contributions to mathematics (Mathematics: It's Content, Methods, and Meaning), but it has by far more math than biography. (It was translated and re-edited by Dover as a one-volume book in E...

- Sun May 15, 2011 2:13 pm UTC
- Forum: Mathematics
- Topic: If you learned statistics would you never buy insurance?
- Replies:
**92** - Views:
**10620**

### Re: If you learned statistics would you never buy insurance?

Practically speaking, the risk of getting in an accident per hour of driving goes down every hour you successfully drive and don't crash I'm pretty sure that if you drive nonstop for 48h your risks of getting in an accident increase :D Say you drive for 8 hours straight. Then an hour break will low...

- Thu Apr 21, 2011 12:52 pm UTC
- Forum: Mathematics
- Topic: Tarski's World
- Replies:
**3** - Views:
**1688**

### Re: Tarski's World

I saw a demo of that program about a year ago in my logic class. It looks a bit like a chessboard and you place objects onto it. The rest is summed up here: http://csli-publications.stanford.edu/site/1575864843.shtml Edit with more detail: If I remember correctly, you have a chess-like board where y...

- Wed Apr 20, 2011 5:29 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 0888: "Heaven"
- Replies:
**131** - Views:
**34473**

### Re: 0888: Heaven

This one was gold. Best one in a while imo

- Mon Apr 04, 2011 1:28 pm UTC
- Forum: Mathematics
- Topic: Which order to learn math topics in?
- Replies:
**24** - Views:
**16373**

### Re: Which order to learn math topics in?

Just something that might interest you, in a lot of math books at the university level they have a tech tree for the material presented, especially when it's a survey book about a new field or something that bridges a couple of fields. So really if Khan Academy has the high school tech tree covered,...

- Thu Mar 31, 2011 1:22 am UTC
- Forum: Mathematics
- Topic: Finite group extensions
- Replies:
**37** - Views:
**3854**

### Re: infinite group extensions

Alright, thanks for clarifying! I took a look at my university's library: nothingness. There's two antique books, one of which is in French (luckily I'm fluent), but they were before this major theorem/breakthrough and their methods involve heavy duty analysis and probability theory. This, on the ot...

- Wed Mar 30, 2011 10:57 pm UTC
- Forum: Mathematics
- Topic: Finite group extensions
- Replies:
**37** - Views:
**3854**

### Re: infinite group extensions

I'm just giving a handwavey idea of why the statement in the talk might be true, this isn't in any way my area of expertise. Ok. By this you mean, Varopoulos' Theorem? Or is this method we are using explicitly stated in the statement for the talk? (in an equivalent form that I'm not "seeing&qu...

- Wed Mar 30, 2011 10:48 pm UTC
- Forum: Individual XKCD Comic Threads
- Topic: 0879: "Lamp"
- Replies:
**151** - Views:
**36122**

### Re: 0879: "Lamp"

Just because you know calculus or java or whatever doesn't mean you can't still let loose and have fun with the standard fair of the net and humanity, and probably even mock and improve upon it. As others said this is a well made version of the joke. I don't claim intellectual high ground. I just d...

- Wed Mar 30, 2011 8:20 pm UTC
- Forum: General
- Topic: Word filter reverseengineerapalooza
- Replies:
**172** - Views:
**17659**

### Re: Word filter reverseengineerapalooza

f i n i t e -> infinite

Combined with this:

I expect serious damage to m a t h threads XD

Combined with this:

DavidSpencer wrote:r e a l -> imaginary

I expect serious damage to m a t h threads XD

- Wed Mar 30, 2011 8:00 pm UTC
- Forum: Mathematics
- Topic: Finite group extensions
- Replies:
**37** - Views:
**3854**

### Re: infinite group extensions

First off, thanks a lot for having spent so much of you.r time explaining this to me! That's partly because things I'm saying aren't entirely true I'm just talking in 'morals'. Nothing below constitutes a proof in any way, you'll have to read the paper for that. You have given me a detailed method, ...

- Wed Mar 30, 2011 3:11 am UTC
- Forum: Mathematics
- Topic: Finite group extensions
- Replies:
**37** - Views:
**3854**

### Re: infinite group extensions

The more I think about this, the less I understand... I believe the idea is that if the group has such elements, then any generating set must also But we have only shown that these elements cannot create e and have infinite order; why is this sufficient to declare that they must be in a generating s...

- Tue Mar 29, 2011 10:05 pm UTC
- Forum: Mathematics
- Topic: Finite group extensions
- Replies:
**37** - Views:
**3854**

### Re: Finite group extensions

Thanks! Do you have some reference for this? Of course I take your word for it, but I'm still a bit shaky as to why this works. DavCrav made up a nice list, I'll check those out when I head to the library today. Edit: something is going wrong here. The subject is supposed to be Fiinite group extensi...

- Tue Mar 29, 2011 4:33 pm UTC
- Forum: Mathematics
- Topic: Finite group extensions
- Replies:
**37** - Views:
**3854**

### Re: Finite group extensions

Actually I'm wrong on that, what you'd need is that e is not a nontrivial combination of the 3 of them So to combine your statements: you want to have three elements, all of infinite order, such that there are no nontrivial combinations of the 3 of them that equal e. Hum let's see if I can work out...

- Mon Mar 28, 2011 3:31 am UTC
- Forum: Mathematics
- Topic: Finite group extensions
- Replies:
**37** - Views:
**3854**

### Re: Finite group extensions

To show that a group isn't a finite extension of Z or Z^2 (e is easy.. is it finite?), you could a) find 3 'independent elements' with infinite order (independent in that none of them lie in the subgroup generated by the other I'm sorry for my ignorance, but could you explain the reasons why this w...

- Fri Mar 25, 2011 6:16 pm UTC
- Forum: Mathematics
- Topic: Finite group extensions
- Replies:
**37** - Views:
**3854**

### Re: Finite group extensions

First off: thanks to all who answered! That there are two contradictory definition is... unfortunate. I should provide the context, then, and perhaps someone will be able to clarify... I am trying to understand the statement of Varopoulos' solution to Kesten's Conjecture. Here is a related link: htt...

- Tue Mar 22, 2011 3:42 am UTC
- Forum: Mathematics
- Topic: Finite group extensions
- Replies:
**37** - Views:
**3854**

### Re: Finite group extensions

Okay, that makes more sense. Thank you both! ^_^ Related question: How would one go about proving something does not have a finite group extension from Z, for example? To prove that it does, you construct such an extension; but to prove that one cannot construct such an extension...? There might be ...

- Tue Mar 22, 2011 12:23 am UTC
- Forum: Mathematics
- Topic: Finite group extensions
- Replies:
**37** - Views:
**3854**

### Re: Finite group extensions

Hum... okay, thank you very much.

Just to make sure I'm on the same page: a field extension is called finite iff the vector space on the field extension is of finite dimension, right?

I'm a bit at a loss as to how these two notions of finite extensions are related.

Just to make sure I'm on the same page: a field extension is called finite iff the vector space on the field extension is of finite dimension, right?

I'm a bit at a loss as to how these two notions of finite extensions are related.

- Mon Mar 21, 2011 8:16 pm UTC
- Forum: Mathematics
- Topic: Finite group extensions
- Replies:
**37** - Views:
**3854**

### Finite group extensions

Could anyone explain to me what a finite group extension is?

I'm familiar with finite field extensions, but I don't see how to similarly define a finite group extension.

I'm familiar with finite field extensions, but I don't see how to similarly define a finite group extension.

- Thu Mar 17, 2011 5:05 pm UTC
- Forum: Mathematics
- Topic: Should I study math?
- Replies:
**22** - Views:
**4571**

### Re: Should I study math?

Others have pretty much said it all already, so I just wanted to give an example. I have a friend who's in mathematical logic, namely category theory. Now, that didn't look remotely applicable to anything other than pure math problems to me, but then he explained that his research is in computationa...

- Wed Mar 16, 2011 6:43 pm UTC
- Forum: Mathematics
- Topic: Should I study math?
- Replies:
**22** - Views:
**4571**

### Re: Should I study math?

I have read Hardy's A mathematician's apology and I was somewhat discouraged (I realise it's quite old but still). He wrote this in 1940. Hitler was carving up Europe. Mussolini was in power in Italy and Fascists controlled Spain. His extremely close friend, Srinivasa Ramanujan, had died. This had ...

- Mon Feb 07, 2011 7:10 am UTC
- Forum: Individual XKCD Comic Threads
- Topic: 0857: "Archimedes"
- Replies:
**137** - Views:
**34960**

### Re: 0857: "Archimedes"

That's something I'd have expected Black Hat Guy to say... o.O

- Fri Feb 04, 2011 5:18 pm UTC
- Forum: General
- Topic: Hype your ripe snipes 'n' gripes
- Replies:
**28619** - Views:
**3483791**

### Re: Rant Thread (because we need more ranting)

Too sugary? Maybe in the icing. But I find the pastry is usually bread-like in supermarket eclairs. Ouch, that's gross =( Yeah you really want to have an éclair when it's fresh. After that it feels like you're chewing on a car tire covered in chocolate. You can find the pastry done properly in some...

- Fri Feb 04, 2011 5:16 pm UTC
- Forum: General
- Topic: Where is the Any key?
- Replies:
**54** - Views:
**7030**

### Re: Where is the Any key?

These are not the keys you are looking for.

- Fri Feb 04, 2011 5:06 pm UTC
- Forum: General
- Topic: Hype your ripe snipes 'n' gripes
- Replies:
**28619** - Views:
**3483791**

### Re: Rant Thread (because we need more ranting)

I have the habit of singing softly when I walk alone. This one time, I was walking back from college and I was singing "The Trooper" by Iron Maiden. That's an awesome song. Haters gonna hate. I think you just had an allergic reaction to their bad music tastes = P I had to stop to get some...

- Fri Feb 04, 2011 4:44 am UTC
- Forum: General
- Topic: Hype your ripe snipes 'n' gripes
- Replies:
**28619** - Views:
**3483791**

### Re: Rant Thread (because we need more ranting)

So... where to begin... Friend getting cancer? Not fun. Friend getting huge operation today for cancer? Not fun. Buuuut it did go well so that's something... He's so young too, it's just really a Rant @ Life moment. On top of that I have to sort out a moronic argument between friends about the most ...

- Tue Jan 18, 2011 10:57 pm UTC
- Forum: General
- Topic: I Shouldn't Have To Say This
- Replies:
**2609** - Views:
**388084**

### Re: I Shouldn't Have To Say This

And if I can't hear you that close, then it's because we're doing 90 and that's not a Moped but a Dark Eldar Reaver and we've got bigger problems. Picturing that totally made my day :D Depends what kind of vehicle is being driven, though; trucks and such have a larger blind spot. On the subject of ...

- Tue Jan 18, 2011 8:16 pm UTC
- Forum: General
- Topic: Firearms the Poll
- Replies:
**85** - Views:
**9796**

### Re: Firearms the Poll

Which is.. again.. why there is no distinction between drawing a weapon and firing the weapon. I really agree with your analysis of that situation in general, but what about when you're in a car, or in your house? Personal anecdotes: a friend's grandma was in her car at night at a gas station in a ...

- Sun Jan 02, 2011 6:21 pm UTC
- Forum: News & Articles
- Topic: Bradley Manning tortured
- Replies:
**429** - Views:
**46977**

### Re: Bradley Manning tortured

It has no relevance because we are aware that the military can legally strip away your rights as a human being. We don't need to be reminded. And frankly, I don't think many of us care. The problem being that it is hard to change something that isn't illegal in a country where both major parties su...

- Sat Jan 01, 2011 12:48 am UTC
- Forum: News & Articles
- Topic: Bradley Manning tortured
- Replies:
**429** - Views:
**46977**

### Re: Bradley Manning tortured

Dream wrote:Do you have anything to add beyond "he doesn't deserve to be treated like a human being"?

dedwrekka is not saying he deserves to be treated this way, just that the law technically allows it.

- Tue Dec 28, 2010 4:05 am UTC
- Forum: Serious Business
- Topic: Depleted Uranium
- Replies:
**53** - Views:
**10229**

### Re: Depleted Uranium

I think some of the worry was towards the people manipulating the munitions too, since they are the ones next to the rounds for a very long time. The radiation is very little, but there was fear that protracted exposure to low levels of radiation would lead to bad things. Source: "Armes Sales, ...

- Tue Dec 28, 2010 3:31 am UTC
- Forum: News & Articles
- Topic: Bradley Manning tortured
- Replies:
**429** - Views:
**46977**

### Re: Bradley Manning tortured

TheGrammarBolshevik wrote:Thanks for clarifying.

Sorry for having been so confusing, and thanks for having stuck with it.

*edit: that should be Soviet Bill of Right, not "Russian" Bill of Right, in my post above. It was supposed to extend to all citizens, not just ethnic Russians*

- Tue Dec 28, 2010 3:27 am UTC
- Forum: News & Articles
- Topic: Bradley Manning tortured
- Replies:
**429** - Views:
**46977**

### Re: Bradley Manning tortured

However, you still aren't addressing the claim that the public laws of various Western nations prohibit the particular type of treatment to which Manning has been subjected. You're just saying that they've been guilty of comparable abuses in other situations. I will concede the point that Western n...

- Tue Dec 28, 2010 3:03 am UTC
- Forum: News & Articles
- Topic: Bradley Manning tortured
- Replies:
**429** - Views:
**46977**

### Re: Bradley Manning tortured

Compare: if I contend that many women are not attracted to men, then pointing to a woman who is is not a counterclaim You point to a fallacy in numbers: "many" requires more than a single counterexample. My argument reaches all the countries involved in the Afghan War, as well as Russia a...