# Search results

1. ### An initial to general state problem (QM Help)

1. A 3 level system starts at time t = 0 in the state \left|\psi_0\right> = \frac{1}{\sqrt2} \left(\begin{array}{cc}1\\1\\0\end{array}\right) The Hamiltonian is H = 3\left(\begin{array}{ccc}1&0&0\\0&1&1\\0&1&1\end{array}\right) If \hbar = 1 find the state \left|\psi_t\right> of the...
2. ### Multiple Integral question

It has been a long while since I've done any multiple integral stuff and I must say this question posed to me has me stumped, even though I suspect it is trivial. 1. Find the volume of the of the region bounded by the first octant and x+z=3 and y+5z=15 I figure since it is in the first...
3. ### Apophis Strikes Earth: Odds still 1 in 45,000

This is sort of in response to an article Ivan posted in the locked Apophis thread: http://www.physorg.com/news127499715.html [Broken] The above is the url from Ivan. Below are urls to the contrary http://www.theregister.co.uk/2008/04/16/esa_german_schoolboy_apophis_denial/?rss...
4. ### A card game

I got into a debate with some people I know here at university and no consensus was reached. For this hypothetical situation, there are four players playing cards. So there are 52 cards, and 4 hands. All the cards are dealt out into four equal piles of 13. What are the chances, that the...
5. ### Need some quick VisualBasic help

I have a visual basic program that outputs strings of numbers to a text file. However currently the output is in the form: 1 2 3 4 5 Note also the space infront of the first number as well. I need for the output to look like: 1,2,3,4,5 However, right now I can only get it to look...
6. ### Computer Program

I'm wondering if there is a program that can do this, and if so which one and how. What I need is a program in which I can make columns with data in it. One column should have its rows be the sum of the corresponding rows in the other columns. Then I need to calculate the correlation of...
7. ### Intriguing Statistical/Probability Question

Recently I became rather bored and decided to play around with random numbers. I utilized a spreadsheet for this. I made 4 columns containing 53 rows. Each entry into a cell was limited to a range between 1 and 300. I then made a 5th column such that each row in the 5 column corresponded to...
8. ### Need help with polynomial fitting

I have two polynomials fit to two different sets of data points. What I need to know is if there is a way to obtain a polynomial such that it will minimize the distance between all the points on both the other polynomials?
9. ### Nonconducting liquid

Does anyone know of any type of liquid that will not dissolve any type of salt (or anything in salt water for example), and is not able to mix with water, that is also non-conductive?
10. ### Amazing new experiment proposed

http://science.nasa.gov/headlines/y2004/26mar_einstein.htm?list531723 [Broken] This would test the predictions of GR 30,000 times better than the current best test--enough to start verifying predictions made by some of the current proposals for TOEs, in terms of descrepancies. Note to...
11. ### Tricky Integral

Given P(x)= \frac{1}{\sigma \sqrt{2\pi}} e ^ \frac { -(x - \mu )^2}{2 \sigma ^2 } This is of course the normal distribution curve. When \mu = 0 and \sigma = 1 I can integrate this from minus infinity to positive infinity no problem using polar coordinates and a bit of multivariable...
12. ### Operation that will undo a curl operation?

Does anyone know if there is an operation that will undo a curl operation?
13. ### Flux question

Ok, here's the question. Without the greenhouse gases in earth's atmosphere the temperature would be 250K. With them it is 40K higher (290K). Using the Stefan-Boltzman equation for flux ( F = &sigma;T4) what is the percentage of infrared radiation leaving the earth's surface taht is...
14. ### Navier Stokes Equation

I recently came across the vector version of the Navier Stokes equations for fluid flow. \displaystyle{\frac{\partial \mathbf{u}}{\partial \mathbf{t}}} + ( \mathbf{u} \cdot \bigtriangledown) \mathbf{u} = v \bigtriangleup \mathbf{u} - grad \ p Ok, all is well until \bigtriangleup. I know...
15. ### Chinese Checkers

Is there an optimal strategy for Chinese Checkers?
16. ### Inspired by the nutcase thread

Well the nutcase thread inspired me to post a very brief and rather dry essay I had to write once for a TOK class. It examines the possibilities of determining whether a claim is pseudoscience or real science. I uploaded the .txt version of it. And on second thought since it is short...
17. ### Chemistry Help!

I cannot for the life of me solve this. Maybe one of you can help? The solubility of N2 in blood at 37 degrees C and at a partial pressure of 0.8atm is 5.6 X 10-4mol/L. A deep-sea diver breathes compressed air with the partial pressure of nitrogen equal to 4.0atm. Assume the the total volume...
18. ### Pressure problem

I have a somewhat unique question here. I know that Pd is a very good absorper of hydrogen. My question is, supposing you start with a given volume of Pd and a given volume of H or even H_2 and it is absorped by the Pd is it possible to calculate the pressure that the hydrogen is under while...
19. ### Let's Play Dice!

Ok, a friend at another forum posted this challenging probability problem. Mike throws 20 6-sided die on the table. He then adds up the results of all the dice, resulting in a number between 20 and 120. What are the chances the total number is equal to or greater than 100? How, in detailed...
20. ### Paired t-test

What is the equation for a paired t-test?
21. ### Two difficult limit problems!

The first one is a mere question. If we are given lim f(x,y) = L, (x,y) -->(&infin;, u) where u represents an unknown, is it possible to figure out what value u must be so that the limit will in fact, be L? And the second one: given: lim [(xx/(x-n)(x-n))-n - ((x-n)(x-n))-n]/n = L for...
22. ### Magnetic Monopoles detected? Mayhaps

http://physicsweb.org/article/news/7/10/2 Apparently the physicists claimed they observed the fingerprint of a monopole in momentum space?
23. ### Need help with something very odd.

Ok, we are given the known equation that momentum = mass times velocity. p=mv. What is dp/dr physically representing? Given: r = position. dr/dt = v. so p = mdr/dt. dp/dr = m/dt ? If so, that remains constant (or zero?) correct?
24. ### A plane intersecting another plane

Here is the question: Find an equation of the plane that passes through the line of intersection of the planes x-z = 1 and y +2z =3 and is perpendicular to the plane x + y -2z =1. Good luck!
25. ### The Shadow of Dark energy

Well, apparently we have now found new and more direct evidence for the existance of the so called 'dark energy.' I find it quite remarkable. http://www.space.com/scienceastronomy/dark_energy_030805.html [Broken]
26. ### On the topic of curved spacetimes

Hurkyl's thread on why it is useful to study curved spaces as well as some discussions with a friend have led me to pose this question: There is a current theory that the universe could be torus shaped because the intrinsic curvature of a torus would be zero, much like that of a flat space...
27. ### 5 quark baryon created

From the American Institute of Physics update. Very interesting.
28. ### Need some force/energy help

Ouch, I got myself stumped. Say we are given the energy of a system (in this case let's consider it a hypothetical gravity wave). I have the energy of the wave that it has, derived from the change in momentum of the object it interacted with. I want to determine the force of gravity between...
29. ### Difference between any two odd numbers is even

Is there a law or theorem somewhere that states the difference between any two odd numbers is even? Or the difference between 2 even numbers is even?
30. ### Chess and Matrices

Just an idle question I suppose...but we all know one can represent a chessboard as an 8 by 8 matrix. Let white be positive and black be negative. Pawns are 1's Rooks are 2's Knights are 3's Bishops are 4's Queens are 5's Kings are 6's empty spaces are 0's Is there any way to use...