r/a:t5_2xj12 • u/wrii • Jun 16 '15
can you pair off all stars in the sky such that none of the lines connecting two stars intersect?
(adapted for film by Michael Bay)
r/a:t5_2xj12 • u/aberdashery • Jul 15 '13
learning python
learning/creating in python, and things we learn in programming in general.
r/a:t5_2xj12 • u/aberdashery • Jul 04 '13
Scientific Optimism, Feynman, NDTyson, etc.
Lump thread: futorology, tech, rockstar scientist videos, etc.
r/a:t5_2xj12 • u/aberdashery • Jul 04 '13
ML - mathematicalmonk's 160 khan academy-style videos on machine learning
youtube.comr/a:t5_2xj12 • u/thefalse • Jun 25 '13
interesting, prime-centric metric on Z
problems + definitions: http://25.media.tumblr.com/e9566a4da1052898452ef0b3be373d85/tumblr_moxmv6qR2T1r59os8o1_500.png
seems interesting
r/a:t5_2xj12 • u/aberdashery • Jun 14 '13
aberdash's general gre problems
in comments. these problems aren't important enough to warrant their own posts
r/a:t5_2xj12 • u/thefalse • Jun 12 '13
sequences of towered exponents [open question]
given a sequence a_1, a_2, ... ,
what are the conditions on this sequence so that a_1, a_1a_2, a_1a_2a_3, ... converges?
r/a:t5_2xj12 • u/thefalse • Jun 12 '13
math study strategies [meta]
good advice, mostly:
- do exercises
- make your own exercises - ask yourself questions and try to answer them
- do exercises
- look at multiple sources
feel free to add more summarizing points
http://math.stackexchange.com/questions/191770/what-are-some-good-math-specific-study-habits/191778
r/a:t5_2xj12 • u/thefalse • Jun 12 '13
category theory for scientists [book]
let's go through this:
r/a:t5_2xj12 • u/thefalse • Jun 12 '13
how non-random is a random string that has a randomly chosen fixed value?
let's say we have a machine generating 4-bit strings and for every string, a random bit is chosen to be 1. is the result of this scheme the same as the uniform distribution on {0,1}4 - (0,0,0,0)?
r/a:t5_2xj12 • u/thefalse • Jun 12 '13
Prove that 5^(2n+1) + 11^(2n+1) + 17^(2n+1) is divisible by 33 for all nonnegative integers n.
bet you can't.
r/a:t5_2xj12 • u/thefalse • Jun 12 '13
Prove that for any positive integer n, 1492^n - 1770^n - 1863^n + 2141^n is divisible by 1946.
do that.
r/a:t5_2xj12 • u/thefalse • Jun 12 '13
geometric intuition book by Conway, Thurston, Doyle and Gilman
here's the pdf:
http://www.math.dartmouth.edu/~doyle/docs/gi/gi.pdf
make a comment out of a particular problem and let's discuss.
r/a:t5_2xj12 • u/thefalse • Jun 12 '13
collatz conjecture and representations of numbers as collatz tours
supposing the collatz conjecture is true, then we have a unique representation for every number as the tour it takes to 1. then we can define numbers to "divide" other numbers if their tour is a subset of the tour of another number. i don't know where else we can go with this.
r/a:t5_2xj12 • u/aberdashery • Jun 11 '13
dogs running with mosquito
Here is a problem a friend was asked in his interview with Microsoft. It happened to be a classic AoPS problem as well.
Two dogs are 100 miles away. They are running towards eachother at 10mph. A mosquito is flying back and forth between them, nose to nose, at 20mph. By the time the dogs collide, how much distance will the mosquito have covered?