Search found 16 matches

by Jorb
Mon Aug 16, 2010 7:54 am UTC
Forum: Science
Topic: magnetic moments of cations
Replies: 2
Views: 1257

magnetic moments of cations

First of all, I'm not getting Hund's rule. At all. I will now commence to explain what I think: having to explain the net magnetic moment of say Fe3+, which is given to be 5, the electrons in 3d occupy different orbitals and have the same spin, but that gives 3 electrons. Are the other 2 from s4? Do...
by Jorb
Wed May 26, 2010 9:00 am UTC
Forum: Mathematics
Topic: Famous Math Quotes!
Replies: 32
Views: 8161

Re: Famous Math Quotes!

"I wouldn't describe myself as being particularly fanatical about mathematical induction, but it is rather cute." - Prof at my university

"Contrary to widespread belief, mathematicians do go to parties" - Ian Stewart
by Jorb
Tue May 18, 2010 3:10 pm UTC
Forum: Science
Topic: 1st course on modern physics
Replies: 2
Views: 773

1st course on modern physics

the first test results came back and less than 30% of the class passed. I guess I'm lucky then. But what I want is examples of problems, because the work really isn't that hard, it's just the way the lecturer asks it that is tricky and different from the textbook. Or any ideas on how to prepare bett...
by Jorb
Thu Jan 14, 2010 1:58 pm UTC
Forum: Mathematics
Topic: roomies
Replies: 8
Views: 1218

Re: roomies

Any amount of people swapping rooms is a single swap. So if you have a configuration of persons in rooms, the next night any other configuration would be one swap.
I'm thinking of just randomizing and then change a few configurations to try get a working model.
by Jorb
Wed Jan 13, 2010 3:28 pm UTC
Forum: Mathematics
Topic: roomies
Replies: 8
Views: 1218

roomies

I've been asked to set up a sleeping roster as follows: Suppose you have 12 people who live in a house with 4 rooms. The rooms can sleep 4, 3, 3 and 2 at a time. If each person has to sleep in every room atleast once and share a room with every other person atleast once, what is the least amount of ...
by Jorb
Sun Dec 13, 2009 9:17 am UTC
Forum: Mathematics
Topic: Why do people keep saying this?
Replies: 42
Views: 4918

Re: Why do people keep saying this?

greengiant wrote:this should be 'an unicorn' I guess but it sounds funny

Nope, a unicorn, an unseen hippo, a hippo, an hour (couldn't think of a relevant word). See the pattern? Vowel sound gets an an.
by Jorb
Mon Oct 12, 2009 7:50 pm UTC
Forum: Mathematics
Topic: Study hobbits and the lack thereof
Replies: 16
Views: 2491

Re: Study hobbits and the lack thereof

No mind maps or story visualizations? I've memorized a grid of numbers as a party trick with the visualization thing, but I never really used it to remember something useful or that can score me marks on a test. On that note, the current record for memorizing numbers in one hour is 1949 digits.
by Jorb
Mon Oct 05, 2009 5:57 pm UTC
Forum: Mathematics
Topic: Study hobbits and the lack thereof
Replies: 16
Views: 2491

Study hobbits and the lack thereof

Anything in particular you do to prepare for a test? I'm wondering mainly about math and related subjects. Do you stare at the page until the formulae come alive? or just do a bunch of problems? Do you sit and memorize formulae? (I only managed to memorize the cubic root thing in 2nd year university...
by Jorb
Sat Aug 08, 2009 11:17 am UTC
Forum: Mathematics
Topic: explicit formula
Replies: 7
Views: 1408

Re: explicit formula

Just because it diverges does not mean there is no explicit formula. Indeed, but my sentence construction skills might have you believe differently. As I posted this I realized that it can be written as the sum of two series x n = a n + b n where a n = (2/3) n b n = ∏(2/3) i(-1)^(i-1...
by Jorb
Sat Aug 08, 2009 11:00 am UTC
Forum: Mathematics
Topic: Cube in a sphere in a cube.
Replies: 6
Views: 1574

Re: Cube in a sphere in a cube.

[quote="stephentyrone"]To be as large as possible, the corners of the little cube should be at the points where those lines intersect the sphere./quote]

Wouldn't the inner cube be the same size no matter how it's rotated?
by Jorb
Sat Aug 08, 2009 10:35 am UTC
Forum: Mathematics
Topic: explicit formula
Replies: 7
Views: 1408

explicit formula

I have to explain this to a high school kid, but I have no clue myself. The question asked for an explicit formula for xn.

xn = 2/3(xn-1 + 1/(xn-1)2)

x0 = 1

I couldn't see any pattern in the iterations, and I believe it diverges, contrary to what the question believes.
by Jorb
Tue Jun 16, 2009 10:34 am UTC
Forum: Books
Topic: Books with gritty realism.
Replies: 11
Views: 2676

Re: Books with gritty realism.

Dostoevsky? Crime and Punishment, Notes From the Underground... I think they fall in that genre, but not as in your face as the wikipedia description suggests it should be.
by Jorb
Fri Jun 12, 2009 9:52 pm UTC
Forum: Mathematics
Topic: Lost art?
Replies: 28
Views: 3416

Re: Lost art?

If you do any algebra, not knowing your multiplication tables will slow you down. Sure. calculators are cheap & easy to use, but swapping between pen & calculator several times per line will slow you down & can interrupt the train of thought. And it's almost impossible to factorize numb...
by Jorb
Fri Jun 12, 2009 8:45 am UTC
Forum: Mathematics
Topic: Lost art?
Replies: 28
Views: 3416

Lost art?

I guess this is kind of related to the 'Are people besoming stupid because technology does everything for us' question. I bought a book with log tables. I think the main reason was so that when someone sees it on my bookshelf they would immediately know I am superior to them in bothknowledge and gee...
by Jorb
Wed Jun 10, 2009 2:42 pm UTC
Forum: Books
Topic: Has any book "marked" you?
Replies: 28
Views: 4234

Re: Has any book "marked" you?

The Underground by Dostoyevski, it scared the crap out of me. I saw myself in the main character and he turned out pretty depraved/disturbed. Made me wonder what I'm capable of.
by Jorb
Wed Jun 10, 2009 8:54 am UTC
Forum: Music
Topic: Recommend one artist
Replies: 1018
Views: 285974

Re: Recommend one artist

Jax Panik, best electro pop south of the sahara

http://www.youtube.com/watch?v=zA2dwSGMmpE

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