Recent content by blaksheep423

  1. B

    Master in Physics vs. Bachelors in Engineering?

    Hello all! I have been searching far and wide for good MSc degree programs in high performance computing, scientific computing, and applied (computational) mathematics that offer distance learning and online programs. I'm working full time and I really like my job and where I am, but there...
  2. B

    Fourier B-coefficients for a tricky f(x)

    Homework Statement compute the Fourier coefficient Bn: Bn = 2/L\intf(x)*sin(kn x) dx where kn = n*pi/L and the integral runs over L (pardon the appearance, I am not very good with LaTeX). Homework Equations f(x) = 1/2(1-cos(2*pi*x/a) for 0 < x < a f(x) = 0 for a < x < L The...
  3. B

    Solving a Radioactive Decay Problem: Na(t) and Nb(t)

    Homework Statement Consider a radiactive decay problem involving two types of nuclei, A and B, with populations Na(t) and Nb(t). Suppose that type A nuclei decay to form type B nuclei, which then also decay, according to differential equations:Homework Equations dNa/dt = - Na/Ta dNb/dt =...
  4. B

    Find Gravitational Force of Photons: Equations & Potential Energy

    It doesn't seem like this should be accurate. If photons are truly massless, then I don't think you can just use E/c^2 as a replacement. Then again, I don't really know at all, which is why I asked. Do einstein's field equations work for energy in any form? Could they be used?
  5. B

    Find Gravitational Force of Photons: Equations & Potential Energy

    How would I go about finding the gravitational force produced by a photon? They are massless, but they must warp spacetime as all energy warps spacetime. What equations could I use to find the gravitational potential energy between two (very close together) photons in terms of their energy?
  6. B

    A Good Book on The Standard Model?

    I am looking for a decent book (probably a textbook) that covers the standard model in its entirety (not necessarily in its vast detail, though). I am a physics undergrad in my 4th year, so I'm looking for something that gets into specific math and theory, but obviously not something that would...
  7. B

    Quantum tunnelling for a finite-square potential parrier

    Homework Statement At x=0, a proton with a kinetic energy of 10 eV is traveling in the x direction (potential energy = 0). At x = 1nm, it encounters a potential barrier of height 12 eV and width .2nm. The potential returns to 0 at x = 1.2nm. Give the amount of the particle on both sides...
  8. B

    Expectation value r^2 for a radial wave function

    ok, i think I've got it now. if anyone sees an error in this post, let me know. the integral above comes from integrating sin(\Theta) from 0 to \pi = 1, and d \phi from 0 - 2\pi = 2\pi. then, integrating from 0 - infinity gives the extra factor of 2, yielding <r2> = (4 \pi)(4/a3) \int r4...
  9. B

    Expectation value r^2 for a radial wave function

    OK, so i understand that the second r2 term came from r d\Theta r sin\Theta d\phi, but where does the 4\pi come from? \phi goes from 0-2\pi, but what about the extra factor of 2? Is it because the function is symmetric, so you're now integrating from 0- infinity and multiplying the result by 2...
  10. B

    Expectation value r^2 for a radial wave function

    Homework Statement The ground state (lowest energy) radial wave function for an electron bound to a proton to form a hydrogen atom is given by the 1s (n=1, l=0) wave function: R10 = (2 / a3/2) exp(-r / a) where r is the distance of the electron from the proton and a is a constant. a)...
  11. B

    Do Photons Produce Gravitational Fields?

    So if a photon does not emit gravitational radiation, is this the reason that a "gravity boom" does not happen?
  12. B

    Do Photons Produce Gravitational Fields?

    Well put, S. Vasojevic. It obviously doesn't happen. And I don't know nearly enough about quantum mechanics (or, to be honest, relativity. I am merely a physics undergrad) to try and comprehend what prevents this. It's just a question I couldn't answer myself and couldn't find an answer to...
  13. B

    Do Photons Produce Gravitational Fields?

    ok, then the next question I've been wondering about is this: if gravity propagates at c, and photons move at the exact same velocity, could a photon traveling in a straight line be constantly affected by it's own gravity at any single point? if so, wouldn't the gravity of each point of the...
  14. B

    Do Photons Produce Gravitational Fields?

    Do photons produce gravitational fields, even though they are massless? In other words, can a photon's gravity affect other photons or elementary particles?
Back
Top