Recent content by sunmaggot

cold body will have entropy increased. hot body will have entropy decreased. In the process of thermal conduction, there is new entropy added. I am not sure about the name of such new entropy, maybe it is called entropy of mixing (not sure). If you try to calculate the entropy change for both...

Progress This is the experimental data of thermal conductivity of stainless steel 304L at low temperature. The data is calculated with the Fourier's law of thermal conduction. I checked many times in the excel file and I confirmed that there is no mistake in the calculation. The parameters are...

I see, so the condition in my question actually cannot happen. Thank you for the replies.

maybe I didn't ask it clearly. Actually I am thinking that the particle defined its own position and made its own wavefunction collapse. So it would not have anymore chance to quantum tunnel? But it should tunnel because for outside observer, the wavefunction includes quantum tunneling.

The QM is saying that a particle in some potential pattern will have a wavefunction that describes the probability to find the particle. And then it also said that observation will make wavefunction collapse into measured value. For example, the electron in an atom will be in one position after...

these three are from griffith's book, so maybe there are more.

maybe I used wrong words. Three opinions maybe better?

I remember there were three kinds of interpretations of a measurement on a particle. 1. realist position, which implies that the particle was there before measurement. Because you didn't do measurement, you did not know it was there. This implies a loophole in quantum mechanics that there is...

x is q?

the taylor series has a term (x-a), what should be the a?

cool, I will try it first!

do you mean taylor expansion??

Homework Statement Given L (q, dq/dt, t). translation: q ---> q + e (e is infinitesimal constant) show that if ∂L/∂q = 0, then L is symmetry under the above translation. then find conserved quantity. Homework Equations S = ∫ L dt The Attempt at a Solution My attempt is nothing... because I...

OHH, I think I got the idea, thank you very much!

wait, got a question here, why would the warrior sees himself got stabbed first? isn't the opponent's lance shorter because of length contraction?