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Dec
16
reviewed Edit The Impossibility ( or Possibility) of Solving $N$-Body Problem
Dec
16
revised The Impossibility ( or Possibility) of Solving $N$-Body Problem
Insert the paper link for easier reference
Dec
11
reviewed Approve Is there an error in Susskinds' derivation of Euler-Lagrange equations?
Dec
11
reviewed Approve Does a body curve spacetime at higher velocities?
Dec
4
reviewed Approve Introducing angular momentum for the first time to a class
Dec
4
comment Questions concerning some parts of the section on one-particle states in Weinberg's first volume on QFT
@ZhengLiu, you're welcome. Yes, the basis $\beta$ is orthonormal in the sense of eq. 2.5.19. $N(p)$ must be different from 1 because the argument of the delta-function changes from the standard momentum $k$ (in eq. 2.5.5 and 2.5.14) to an arbitrary momentum $p$ in eq. 2.5.19. The text between eqns 2.5.14 and 2.5.19 works out the proportionality factor between these two delta-functions, and $N(p)$ is selected to cancel that factor.
Dec
3
reviewed Reject What is the cause of rolling friction? & why is it less than sliding friction?
Dec
2
reviewed Approve What really cause light/photons to appear slower in media?
Dec
2
reviewed Approve How does this “simple” electric train work?
Nov
23
reviewed Approve Ames Room, how to construct properly?
Nov
23
reviewed Approve Can causality be violated?
Nov
22
reviewed Approve What if the centripetal force were acting outward?
Nov
21
reviewed Reject Problem in deducing the equations of motion using indefinite integral
Nov
10
reviewed Approve The correspondence between real space and reciprocal space
Nov
7
comment Deriving Heaviside-Feynman formula for the electric field of an arbitrarily moving charge from Lienard-Wiechert potential
@guillefix, ok I see. I should have read more closely before piping up. Nice approach! (But how can you not trust something by someone named Field?)
Nov
7
revised Deriving Heaviside-Feynman formula for the electric field of an arbitrarily moving charge from Lienard-Wiechert potential
typo
Nov
7
answered Deriving Heaviside-Feynman formula for the electric field of an arbitrarily moving charge from Lienard-Wiechert potential
Nov
7
comment Feynman's proof for Liénard-Wiechert's potential of a moving charge
@guillefix, think I got it. Thanks again for the catch.
Nov
7
revised Feynman's proof for Liénard-Wiechert's potential of a moving charge
minding my c's
Nov
6
comment Feynman's proof for Liénard-Wiechert's potential of a moving charge
@guillefix, thanks! I see now I got sloppy with $c$ in a couple places. (I understand better now why people set $c=1$!) I will patch it today or tomorrow. (I think I need more time than I've got right now, to avoid making another goof.)