This might be a dumb question but I'm still going to ask it. So basically I've been trying to learn Special Relativity through this lecture by Brian Greene, and the way he justifies time dilation is through a Light Clock. I think I understand this, but I just don't know how I could picture this w...

In the solution, why is the the complex time not considered and real and positive time is considered? Is it because complex time does not exist or there is some other reason?

I have a few questions which have all seemingly originated from the following thought: Question 1 It is known that torque is given by τ=r × F. If we use the formulae F=mdv/dt and v=ω × r, we arrive at: τ=r × m(dω/dt × r + ω × dr/dt)=-m(r × r × dω/dt)+m(v × v)=$0$ My first thought was: Why is this...

For monatomic gasses, the heat capacity approaches $3R/2$ because there are three DoF of translational motion. For diatomic gasses it approaches $7R/2$ because the symmetry about its axis cancels out one rotational DoF but it also has two vibrational modes. And for complex molecules you get up th...

We know that the diffusion equation can be viewed as the continuum limit of a discreet unbiased random walk. My question is the following: Is diffusion (or an unbiased random walk) a non-equilibrium phenomenon?