Search found 18 matches

Thu Sep 30, 2010 7:09 pm UTC
Forum: Mathematics
Topic: Dual of Linear Map
Replies: 2
Views: 675

Dual of Linear Map

(For homework, but just need to understand the question.) I want to show if T: V -> W is linear, then T*: W* -> V* is linear. To show T* has additive property, do I need to show that: T*(g+g')(v) = T*g(v) + T*g'(v) (Where g and g' are functionals), or do I need to show: T*g(v+v') = T*g(v) + T*g(v') ...
Tue Nov 10, 2009 12:20 pm UTC
Forum: Logic Puzzles
Topic: The one that stumped the teachers.
Replies: 17
Views: 3324

Re: The one that stumped the teachers.

Spoiler:

Code: Select all

`---  |----      |-----           |           |           |           |           |           |           |           |           |--|              |              |              |              |              |-----`
Thu Oct 22, 2009 8:11 pm UTC
Forum: Mathematics
Topic: Octahedron-Cube
Replies: 4
Views: 1874

Octahedron-Cube

From wikipedia, "If the original cube has edge length 1, its dual octahedron has edge length sqrt{2}." I'm having a hard time visualizing how this would be the case. For example, using this: http://www.math.uiowa.edu/~goodman/algebrabook.dir/graphics.gif/cube-octa.GIF If the sides of that ...
Fri Sep 04, 2009 4:40 pm UTC
Forum: Science
Topic: Food Mass
Replies: 6
Views: 778

Food Mass

Maybe someone on these forums can help me out. I was wondering, when your body turns food into energy, is mass lost or does it stay conserved? I ask because I have heard that a significant amount of the mass was turned into energy, but I have also heard that even if you get energy from a chemical re...
Fri Aug 07, 2009 4:36 pm UTC
Forum: Logic Puzzles
Topic: Guess Who?
Replies: 22
Views: 7443

Re: Guess Who?

Is there a requirement that all questions be answerable with yes or no? If not, you should be able to get it down to 1/3 each time by asking something that is unanswerable given certain conditions. For example, "Is the person blond, OR is it a man AND the answer to this question is no" Blo...
Thu Aug 06, 2009 7:11 pm UTC
Forum: Logic Puzzles
Topic: Solution for 4 students, 4 boxes
Replies: 2
Views: 1395

Solution for 4 students, 4 boxes

Sorry for making a solution thread to a locked puzzle, but I'm stumped, and he solution thread to the equivalent puzzle had me equally confused. Anyways, for reference: The puzzle I am referring to: http://forums.xkcd.com/viewtopic.php?f=3&t=38673 The solution thread for the equivalent puzzle: h...
Fri Jun 19, 2009 4:03 pm UTC
Forum: Mathematics
Topic: Erdos Conjecture
Replies: 17
Views: 5984

Erdos Conjecture

So, today's comic led me to the wikipedia page on Paul Erdos, and from there to the page on "Erdős conjecture on arithmetic progressions". My question is what restrictions are there on the set in the problem? I am not too familiar with sets outside of the problem, so I am probably missing ...
Thu Apr 30, 2009 7:36 pm UTC
Forum: Mathematics
Topic: Taylor Series
Replies: 4
Views: 1000

Taylor Series

So, we started learning about Taylor series in school today. We learned that the general form for f(x) centered at c is: f(c)+f'(C)(X-C)/1!+f''(C)(X-C)^2/2!... The problem I have is applying that to the example we got in class: f(x)=e^(x^2) centered at 0. Based on the formula above my work was this:...
Mon Jan 26, 2009 10:32 pm UTC
Forum: News & Articles
Topic: My President is Black, Fox News Complains
Replies: 310
Views: 19394

Re: My President is Black, Fox News Complains

It seems to me that at this point in the discussion everyone seems to agree that there are discrepancies in treatment on the basis of race. If the reader is still unconvinced, they should read the evidence about the death penalty, job applications, mandatory minimums, etc. The misunderstanding, and ...
Sun Jul 20, 2008 5:58 pm UTC
Topic: Ask (Or just berate) a Literary Theorist
Replies: 129
Views: 29848

Re: Ask (Or just berate) a Literary Theorist

"All art and literature involves becoming a particular audience - stepping into a particular role expected of us by the text. We do this every day - mold ourselves briefly into these audience roles." What relationship does this effect have on the author? If we mold ourselves as receivers o...
Sat Jul 19, 2008 6:35 pm UTC
Forum: News & Articles
Topic: Sean Tevis: "XKCD homage style" comic in campaign
Replies: 67
Views: 9777

Re: Sean Tevis: "XKCD homage style" comic in campaign

I love the comic, and from what I have seen he looks like an awesome candidate (albeit I haven't seen much) HOWEVER I am VERY MUCH BOTHERED that anyone who is presumably a fan of xkcd would reverse the axes on a graph. Failure/success is the dependent variable, pleasantries is the independent variab...
Thu Jun 12, 2008 11:17 pm UTC
Forum: News & Articles
Topic: SC Says detainees can appeal to civilian courts
Replies: 14
Views: 1750

SC Says detainees can appeal to civilian courts

The article is here: http://www.comcast.net/articles/news-general/20080612/Scotus.Guantanamo/ Some questions/opinions that I have: "Bush said he strongly disagreed with the decision — the third time the court has repudiated him on the detainees — and suggested he might seek yet another law to k...
Tue Apr 22, 2008 12:41 am UTC
Topic: Ben Stein vs. Darwin: The Movie
Replies: 165
Views: 15488

Re: Ben Stein vs. Darwin: The Movie

http://www.asa3.org/ASA/PSCF/1992/PSCF6-92Dickerson.html For the lazy people the basic arguments are: 1. ID isn't be science because the point of science is to seek natural explanations. Thus, even if it were true, it wouldn't be science, because all we would learn is "science has no explanatio...
Sun Apr 06, 2008 3:01 am UTC
Forum: General
Topic: Comedians
Replies: 101
Views: 11188

Re: Comedians

Jeff Dunham is absolutely hilarious. I'm surprised no one has mentioned him yet (either that, or I just missed it).
Sun Mar 23, 2008 4:16 am UTC
Forum: Science
Topic: Quantum Mechanics and Consiousness
Replies: 115
Views: 7783

Re: Quantum Mechanics and Consiousness

With electrons, for example, bouncing a photon off of one (if you could actually hit an electron with a photon, you usually can't since a photon's wavelength is too long) would excite the electron, making it jump up an energy level in whatever atom it's in. Therefore, by the time the photon gets ba...
Sun Feb 24, 2008 5:52 pm UTC
Forum: Science
Topic: Reflection
Replies: 4
Views: 1498

Reflection

Sorry if this has already been asked, but a quick search of reflection yielded no useful results. As I understand it, a black surface is one in which light is absorbed. Photons hit a surface, are (mostly) absorbed, and our eye sees black. A white surface is when it is reflected. Photons hit a surfac...
Thu Jan 31, 2008 10:14 pm UTC
Forum: Mathematics
Topic: Is 0 real?
Replies: 43
Views: 10182

Re: Is 0 real?

There are limitations on numbers that can be used for length. You also can't have negative lengths. That doesn't mean that negative numbers don't exist. For f(x)=1/(x 2 -1), X can't be one, but 1 exists. Length just has similar restrictions. As for the number of pencils, what you have just shown is ...
Mon Jan 28, 2008 1:06 am UTC
Forum: Science
Topic: Miscellaneous Science Questions
Replies: 2934
Views: 700362

Re: Common Questions

Not only does matter not travel faster than light, neither does information. No matter how hard you spin those entangled photons. While I am not sure whether it qualifies as information, I do believe that a wave function collapses instantaneously after an observation, as well as all wave functions ...