## Search found 59 matches

Tue Jul 30, 2013 5:10 am UTC
Forum: Books
Topic: Harry Potter and the Methods of Rationality
Replies: 1036
Views: 400472

### Re: Harry Potter and the Methods of Rationality

Snark wrote:Edit: Did anyone else get chills while reading Chapter 96?

Yep. At the inscription. Also, pretty much anytime patronuses or patronus light is mentioned, actually.
Thu Dec 09, 2010 6:41 pm UTC
Forum: Mathematics
Topic: Favorite math jokes
Replies: 1452
Views: 483127

### Re: Favorite math jokes

I searched for this and don't think it was posted. I think it's pretty humorous. Theorem: The nth root of 2 is irrational for n >= 3. Proof: Suppose not. Then there exist relatively prime integers p and q so that p n / q n = 2, and hence p n = q n + q n . By Fermat's Last Theorem, however, there can...
Thu Nov 18, 2010 2:29 am UTC
Forum: School
Topic: "When am I going to use this?"
Replies: 127
Views: 22778

### Re: "When am I going to use this?"

your ignorance prevents you from seeing the same is true of math.
Tue Nov 16, 2010 2:53 am UTC
Forum: School
Topic: "When am I going to use this?"
Replies: 127
Views: 22778

### Re: "When am I going to use this?"

If your child doesn't want to learn how to read and cites the same argument, would you buy it?
Sun Jul 04, 2010 12:31 am UTC
Forum: Mathematics
Topic: Is it just me, or does the average guy really suck at math?
Replies: 57
Views: 7900

### Re: Is it just me, or does the average guy really suck at ma

Did the script get it wrong, or did the characters get it wrong? If it's just the latter, then there's no contradiction with a (smart!) professor being consulted on the math, because it just means the characters are very dumb.
Tue Jun 15, 2010 5:29 pm UTC
Forum: Mathematics
Topic: Any way to recover differences in subjective judging?
Replies: 3
Views: 836

### Re: Any way to recover differences in subjective judging?

Thanks for the references! Cohen's kappa sounds similar to what I want; I'll keep looking.
Tue Jun 15, 2010 3:37 am UTC
Forum: Mathematics
Topic: Any way to recover differences in subjective judging?
Replies: 3
Views: 836

### Any way to recover differences in subjective judging?

Suppose we have m competitors and n judges. Each judge uses her own private evaluation method to assign a value to each competitor. The judge then releases (to the public) her ranking of the competitors, from best to worst — the actual values are not released, so we don't know how much better the fi...
Sun May 30, 2010 9:25 pm UTC
Forum: Mathematics
Topic: How to become a math professor?
Replies: 25
Views: 5467

### Re: How to become a math professor?

Don't learn German or French or Russian. Learn math. Yes, it's very competitive. There are many more aspiring math professors than there are math professor openings. It is a requirement in many math departments to learn German or French or Russian, but that is on its way out — the program I'm in now...
Thu May 27, 2010 3:37 pm UTC
Forum: School
Topic: "When am I going to use this?"
Replies: 127
Views: 22778

### Re: "When am I going to use this?"

Cool! thanks.
Thu May 27, 2010 4:08 am UTC
Forum: School
Topic: "When am I going to use this?"
Replies: 127
Views: 22778

### Re: "When am I going to use this?"

I'm a bit late to this conversation... Yakk, is your description of the incentives faced in elementary/high school based on personal observation, and is there somewhere I can read more about it? I'm fascinated by this stuff.
Thu May 27, 2010 2:05 am UTC
Forum: School
Topic: How to pick a graduate school (mathematics)
Replies: 8
Views: 1415

### Re: How to pick a graduate school (mathematics)

To add a different view, I applied for graduate school in math without having any idea what I wanted to study. If you've had undergraduate research experience and can show interest in some of the classes you've taken, that's good; I don't think it's necessary to know what you want to study while you...
Fri Apr 23, 2010 2:14 am UTC
Forum: School
Topic: Observing teachers who may or may not be bad
Replies: 40
Views: 6787

### Re: Observing teachers who may or may not be bad

I'm a graduate student at a large-ish university in the US. For each of the undergraduate intro courses in my department, there is a department-wide final exam; there are several sections of the same course, and so the professors teaching the course save time by teaming up to write the problems. I h...
Sun Mar 21, 2010 3:02 pm UTC
Forum: Mathematics
Topic: Math in Moscow
Replies: 29
Views: 6690

### Re: Math in Moscow

Just to put it on your radar, there's also a great math program called the Budapest Semesters in Mathematics. Yes, Russian math is great, but so is Hungarian math.

www.budapestsemesters.com for the American page
www.bsmath.hu for the course syllabi, academic program, etc.
Fri Feb 12, 2010 7:22 am UTC
Forum: Mathematics
Topic: Why is this true?
Replies: 12
Views: 1674

### Re: Why is this true?

I guess I was unclear. I was heading in the direction of:

zn - 1 = (z - z1)(z - z2)...(z - zn)

where z1, z2, ... , zn are the n roots of 1. Expand the right hand side, and equate coefficients.
Fri Feb 12, 2010 1:41 am UTC
Forum: Mathematics
Topic: Why is this true?
Replies: 12
Views: 1674

### Re: Why is this true?

Here's an alternative approach. You want the product of the roots of the polynomial f(z) = zn-1. Do you know of any results that let you write this degree n polynomial as a product of polynomials of lesser degree?
Tue Dec 08, 2009 6:26 am UTC
Forum: General
Topic: The legal status of artificial/uploaded minds
Replies: 21
Views: 2018

### Re: The legal status of artificial/uploaded minds

I won't go ahead and answer each individual question you pose, but I think they can all be tackled through the same framework: I think the proper way to deal with the legal and moral issues surrounding artificial minds is to consider the needs and desires of an artificial/digital mind. This is trick...
Tue Jul 21, 2009 10:24 pm UTC
Forum: Logic Puzzles
Topic: Infinite queens on an infinite chessboard
Replies: 35
Views: 25791

### Re: Infinite queens on an infinite chessboard

That's not quite right userxp, you can't guarantee that you will ever get to a specified row/column/diagonal. However with a little twerk: There are a countably finite total number of rows/columns/diagonals. Therefore we can give them an index with the natural numbers. For the lowest index line whi...
Fri Jun 12, 2009 2:02 am UTC
Forum: Mathematics
Topic: Hyperplane cutting up objects
Replies: 2
Views: 447

### Re: Hyperplane cutting up objects

http://en.wikipedia.org/wiki/Ham_sandwich_theorem

Yup, your intuition is right, but it's not exactly trivial.
Tue May 19, 2009 6:01 am UTC
Forum: Mathematics
Topic: Help with a proof that should be easy
Replies: 13
Views: 1137

### Re: Help with a proof that should be easy

That last statement sounds right; change your basis so that the orthogonal hyperplanes have normals along the coordinate axes, and consider the vector normal (call it v 0 ) to the boundary of your half-space and pointing inside the half space. A vector points outside (or along the boundary of) the h...
Fri Apr 17, 2009 5:35 pm UTC
Forum: Mathematics
Topic: Relationship between total derivative and integral
Replies: 11
Views: 2788

### Re: Relationship between total derivative and integral

What you're looking for is Stoke's Theorem . It's an absolutely incredible generalization of the Fundamental Theorem of Calculus, but it's beyond the level of a usual introductory course in multivariable calculus, where you'll probably be learning things like iterated integrals and Lagrange multipli...
Thu Apr 16, 2009 10:50 pm UTC
Forum: School
Topic: Making Teaching Scale
Replies: 2
Views: 827

### Re: Making Teaching Scale

I think one problem (before college level anyway) is that teachers' jobs don't just include teaching but also babysitting. At the college level presumably students want to be there and so you can have things like online lectures and gigantic lecture halls. In primary school, however, the teacher is ...
Wed Mar 25, 2009 12:06 am UTC
Forum: General
Topic: Ability to describe knowledge = knowledge?
Replies: 24
Views: 2270

### Re: Ability to describe knowledge = knowledge?

Another example which stays away from the realm of conscious experience is proposed by Richard Feynman. He gives the example of knowing what a car's crankshaft looks like and how it works without easily being able to describe that knowledge to someone else. Although it's describable in principle (un...
Sat Mar 21, 2009 4:04 am UTC
Forum: Mathematics
Topic: Uncountably many vertical asymptotes?
Replies: 18
Views: 2075

### Re: Uncountably many vertical asymptotes?

Let {r_n} be an enumeration of Q which is dense in R. Suppose it works out that delta(r_n) = 1/2^n; then the measure of the union of all the [r_n - delta(r_n), r_n + delta(r_n)] is at most 2, so the union of the intervals can't be all of R.
Mon Mar 02, 2009 11:56 pm UTC
Forum: Mathematics
Topic: Algebraically formulating a geometric idea
Replies: 7
Views: 1009

### Re: Stating a fact more algebraically

You start by saying subset and then switch to subspace: are you talking about subspaces of a vector space? Maybe use that the angle between a vector in your hyperplane and a vector in your rotated set is smaller than a certain amount (enough so that your set fits inside a cylinder of radius d) in or...
Sat Feb 28, 2009 7:46 pm UTC
Forum: Mathematics
Topic: Homework help, Banach spaces...
Replies: 6
Views: 751

### Re: Homework help, Banach spaces...

Is that a Cauchy sequence? If so, does it converge (under your norm) to a function which is continuous on [0,2]? If it had to converge to some function, what would that function be?
Wed Feb 18, 2009 6:36 am UTC
Forum: Mathematics
Topic: I challenge you!
Replies: 15
Views: 1676

### Re: I challenge you!

I voted leave long chains. But only because I've seen that book before and made it through a chapter or two.
Mon Feb 16, 2009 2:55 am UTC
Forum: Logic Puzzles
Topic: The "Wanion" Hand Cipher
Replies: 6
Views: 1855

### Re: The "Wanion" Hand Cipher

The letters that appear directly before an often-repeated sequence will probably share the first two digits of their cypher code. For example: adkktc occurs 15 times, and only after a, f, and b. This suggests that a, f, and b share the first two digits of their cypher. Similarly, arptzd appears 9 ti...
Sun Feb 08, 2009 7:46 am UTC
Forum: Mathematics
Topic: Favorite math jokes
Replies: 1452
Views: 483127

### Re: Favorite math jokes

I did a search, but I might have missed if this one was told already. I heard it just the other day.

What did the natural log of the first primitive sixteenth root of unity say when all the pie was gone?

"I overate!"
Wed Jan 14, 2009 7:09 am UTC
Forum: Mathematics
Topic: PDE removing a variable
Replies: 2
Views: 658

### Re: PDE removing a variable

More specifically, use the chain rule for partial derivatives:
http://en.wikipedia.org/wiki/Chain_rule ... _variables

Also you may find the following article to be relevant:
http://en.wikipedia.org/wiki/Method_of_characteristics
Sun Dec 14, 2008 4:12 am UTC
Forum: Logic Puzzles
Topic: murder riddle
Replies: 19
Views: 2812

### Re: murder riddle

Or, the bullet hole in his head was a non-lethal wound through his ear that he acquired in his youth (similarly for the hole in the seat) at some point when the window was down.

This time, however, someone stuck a snake/wild beast/grenade in there with him.
Sun Dec 14, 2008 4:07 am UTC
Forum: Logic Puzzles
Topic: Outsmarting the Genie
Replies: 257
Views: 25247

### Re: Outsmarting the Genie

Perhaps the safest bet is to suitably encode the molecular structure of whatever you would like the world to be like after your wish is performed, and then ask the genie to make the world like that? I'll leave the details of how to specifically request this to someone else. The idea being, remove al...
Sat Aug 23, 2008 8:21 pm UTC
Forum: Language/Linguistics
Topic: Words that are their own opposite
Replies: 67
Views: 9204

### Re: Not a logic puzzle, but...

Spoiler:
I'd go with "suck" and "blow."
Fri Aug 15, 2008 5:23 am UTC
Forum: Logic Puzzles
Topic: Two Pieces of Paper
Replies: 7
Views: 2741

### Re: Two Pieces of Paper

It doesn't matter whether you rotate or reflect the board, because the ANSWER IS POTATOES. Other than the fact that "potatoes" is a word that can be found on that boggle board and which neither of the two players found, I don't see how that's relevant, much less the answer. Enlighten?
Fri Aug 15, 2008 4:13 am UTC
Forum: Logic Puzzles
Topic: Two Pieces of Paper
Replies: 7
Views: 2741

### Re: Two Pieces of Paper

I just got well and truly sniped. Well done. The two lists with crossed out words, along with the hint, suggest a boggle game between two extremely skilled players. Finding out the number of blocks for each letter wasn't too bad; finding the locations was a lot worse. A long analysis finally yie...
Sun Jul 13, 2008 8:03 pm UTC
Forum: Mathematics
Topic: Mathematicians on wikipedia display liberal bias
Replies: 35
Views: 6016

### Re: Mathematicians on wikipedia display liberal bias

Since no one has mentioned it yet, the liberal bias claim most likely comes from the fact that conservative mathematicians do not accept the Axiom of Choice. In fact, most of them are notoriously Anti-Choice, claiming that people never have the right to choose to abort a baby one element from each s...
Sun May 04, 2008 7:44 pm UTC
Forum: Language/Linguistics
Topic: Other Languages You've Studied
Replies: 488
Views: 94217

### Re: Other Languages You've Studied

Magyar nem vagyok. Csak egy kicsit tudok érteni magyarul. Még kisebb tudok beszélni.

"I'm not Hungarian. I can only understand a little bit of Hungarian. I can speak even less."

(Did I get that right?)
Fri May 02, 2008 7:55 pm UTC
Forum: Language/Linguistics
Topic: Other Languages You've Studied
Replies: 488
Views: 94217

### Re: Other Languages You've Studied

ZLVT wrote:beer is sör or sőr (I forget) but NOT sür, and wine is bór I think (I'm terrible with vowel length)

Bocánat, nem értem. Csak [egy] kicsit beslek magyarul. - I'm sorry, I don't understand. I only speak a little Hungarian.

Bocsánat. Sör nagyon jó.
Wed Apr 30, 2008 1:18 am UTC
Forum: Mathematics
Replies: 31
Views: 2526

### Re: Math Paradoxes for English

I like to use the following example:

Consider an infinitely long table, with infinitely many place settings. We could never count up all the knives and all the forks, but we know that there are the same number of forks as there are knives because we can match them up.
Tue Apr 22, 2008 10:44 pm UTC
Forum: Language/Linguistics
Topic: Analysis References
Replies: 2
Views: 1636

### Re: Analysis References

Also try scholar.google.com for a book of wordsworth poems. Then select the "cited by 149" link, or whatever.
Fri Apr 18, 2008 8:50 pm UTC
Forum: Language/Linguistics
Topic: Bag Beg Big Bog Bug
Replies: 45
Views: 20274

### Re: Bag Beg Big Bog Bug

Is "bout" usually transcribed as [bɑʊt]? I've seen that vowel sound more often transcribed as [baʊt], and I even say it more like [bæʊt].