Recent content by r_tea

Actually, I think I solved my own problem. It is true that for two identical spins the total angular momentum states follow the symmetry pattern: L_\text{total,max} \rightarrow \text {Symmetric} L_\text{total,max}-1 \rightarrow \text {Antisymmetric} L_\text{total,max}-2 \rightarrow \text...

This problem is 1.1b out of "Atomic Physics" by Budker, Kimball, and Demille. There are solutions in the book, but I am confused: I'm asked to find the ground state configuration of Phosphorus, which is has 3 P-state valence electrons. Following Hund's rule, we want to find a state with largest...

Sorry, I missed your point--sorry if this became confusing. In the case of a molecule, i.e. two masses connected by a spring, then there are 3 degrees of freedom. 1. The CM motion of the molecule. 2. The relative motion of the molecules. and 3. The vibrational potential energy. The single...

Okay, I see where you're going with this. Yes, in that case I was talking about CM motion--it's just a mass on a spring, hence the location of the mass is the center of mass. Since I just said "CM motion doesn't count in temperature", and here were are talking CM motion and temperature, you may...

Yeah so internal energy is the total energy that arises due to random, or statistical events. I think I used the world "average" sloppily: The internal energy, U, is the total energy of the system of N particles, and if you divide the internal energy by the number of particles, U/n, that's now...

Right, exactly--the states are different in the exact special way that U1=U2 (which is exactly the definition of an isothermal process for an ideal gas). What I meant to say was that there's no reason to intuitively believe that U1 should be different than U2, because U alone doesn't specify...

So, what I think you're saying is "U should entirely specify the state of my system because it is a state function, hence if I have some state where U=something and another state where U=same thing, then those two states should be the same, but they clearly aren't because they have different...

The short story: So, in thermodynamics there's this thing called the "equipartition theorem", which says every "degree of freedom" in your system contributes 0.5kT to the total average energy. For example, if you have a one dimensional, ideal (non-interacting) gas, then you would be correct in...

Also a polarizing beam splitter (with the right waveplates if you want max power out of one of the outputs). If you're going to use lenses don't forget to use achromatic lenses if the wavelengths of the beams are very different.

Thanks. I'm surprised it was that simple...

Perhaps this question is silly, but I don't entirely understand how elastic scattering of photons is even possible given that the directions of the incident/scattered photon differ. If there is a change in direction of the photons momentum, then there must be some momentum transferred to the...

p=mv/sqrt(1-(v/c)2) or more commonly p=mv\gamma, where \gamma=\frac{1}{\sqrt{1-(v/c)^{2}}}

Although all the posts above me are right (i.e. in physics something is proven if it works against observation), I guess a few of those formulas stem from more fundamental ideas, which cannot be proven mathematically (either because they're defined to be true or they work experimentally)...

Ionization energy is defined as the energy needed to remove an electron from an isolated atom. I think the term usually gets associated with gases because, experimentally speaking, you could measure ionization energy from a gas since the atomic spacing is huge compared to the atoms themselves...