Recent content by transience

  1. T

    Equation of Continuity of charge for point charges

    Homework Statement I am looking to demonstrate that the expressions for the charge and current density of point charges satisfy the equation of continuity of charge. Intuitively it makes sense to me but I run into trouble with the delta function when I try to prove it mathematically.Homework...
  2. T

    Wavelength Function and Diffraction Orders Explained

    The best way that I can think of to explain this is by example. A spectrometer spatially resolves the spectrum of the light source that you are analysing with it. If you take a source that has a narrow bandwidth like a c.w. laser then the spectrum of the laser will only have a single line...
  3. T

    A quick(?) question about the Pauli exclusion principle

    I believe the apparent violation of the exculsion principle was used to show that another quantum number (dubbed colour) exists.
  4. T

    History of the Taylor-Phipps version of the Stern-Gerlach experiment

    Thank you, The fact that the Schrodinger equation could explain the helium energy and the Bohr-Sommerfeld model could not is exactly what I was missing.
  5. T

    Why amplitude squared gives probability / Schrodinger Equation

    If you have a number that you know has been squared then by finding the square root of this number you will find all of the information about the original number EXCEPT for its sign. For instance if you know that x^2=9 then you know that |x|=3 but you don't know whether x=+3 or -3 unless you can...
  6. T

    Born-Oppenheimer approximation

    Are you trying to find the full Hamiltonian? If so you need to add up all contributions to the energy from the different sources and then apply the Born-Oppenheimer approximation. The Born-Oppenheimer treats the nuclei as fixed, so they have zero kinetic energy and the interaction between...
  7. T

    Explaining electrical resistivity behaviour from phonon perspective

    From my (3rd year undergraduate) understanding phonons increase the resistivity for metals because they scatter electrons. Have you considered defects? They are known to decrease as temperature is increased and I would expect that a noncrystaline metal would have plenty of them, it would depend...
  8. T

    Effective mass of a charge carrier

    For Bloch electrons? The effective mass is inversely proportional to the curvature of the \epsilon vs k graph for the band that the carrier is in.
  9. T

    Physics Challenge: Explaining Forces & Common Ground

    There is no underlying physical law that prevents them from being different to they way they are (i.e. they could have different strengths), that we know of that is.
  10. T

    History of the Taylor-Phipps version of the Stern-Gerlach experiment

    Hi, I'm at the tail end of writing an essay about the Stern-Gerlach experiment and I am wondering if anyone knows of any reliable sources that discuss the historical context of the Taylor-Phipps version of the Stern-Gerlach experiment using hydrogen. All of the sources that I find use the...
  11. T

    Schools My Grad School Chances for AMO Physics

    I have been told that having publications has a lot of weight when you are looking at graduate study.
  12. T

    Thin, light, cheap and strong as wood material?

    Why can't you use wood? Fibre glass might work depending upon the application.
  13. T

    Is Quantum Measurement Uncertainty Due to Methods or the Act of Observation?

    It must be noted that you can't have an arbitrary small particle, there is a lower limit on length known as the plank length.
  14. T

    Ensuring Clean Quantum Measurements in the Stern-Gerlach Experiment

    The way I understand it is that the Stern-Gerlach experiment is a measurement device that splits the beam according to the projection of the spin component on the z-axis. The quantum state of whatever makes up the beam isn't pure, meaning that the the z component of the spin can be expressed in...
Back
Top