user avatar
user avatar
user avatar
Physiks lover
  • Member for 10 years, 11 months
  • Last seen this week
39 votes
5 answers
8k views

Does a photon in vacuum have a rest frame?

29 votes
8 answers
8k views

Why is there a $\frac 1 2$ in $\frac 1 2 mv^2$?

10 votes
4 answers
831 views

Why isn't there a limit for a Euclidean rotation, as for a Minkowski rotation?

7 votes
2 answers
651 views

What experiments compete with BICEP 2, and when are their results expected?

7 votes
2 answers
351 views

How does Dirac define the representative of $\{\langle\phi\frac{d}{dq}\}\psi\rangle = \langle\phi\{\frac{d}{dq}\psi\rangle\}$

7 votes
8 answers
3k views

Is Einstein's 1916 General Relativity paper a recommended way to start learning about the subject?

6 votes
2 answers
4k views

Is the change in kinetic energy of a particle frame independent?

6 votes
1 answer
183 views

Why isn't EM radiation from an accelerated charge time reversible?

5 votes
2 answers
198 views

Do Maxwell's equations contain any information on the time evolution of the current density $J$?

5 votes
2 answers
3k views

Is (0,0,0) an undefined vector?

5 votes
3 answers
2k views

Explanation for $E~$ not falling off at $1/r^2$ for infinite line and sheet charges?

5 votes
4 answers
2k views

Are the principles of space-time homogeneity and Isotropy independent of one another?

5 votes
2 answers
153 views

Should the eigenkets be weighted in $|P\rangle = \sum\limits_{r}|\xi^r\rangle$?

4 votes
4 answers
9k views

Is the electric field zero inside an ideal conductor carrying a current?

4 votes
1 answer
309 views

Is there a Newton's third law for the em field?

4 votes
1 answer
4k views

Proofs that every professional physicist should know [closed]

3 votes
1 answer
4k views

Problems that Lagranges equations of the 1st kind can solve whereas the 2nd kind can't?

3 votes
1 answer
2k views

Can relativistic kinetic energy be derived from Newtonian kinetic energy?

3 votes
3 answers
4k views

Calculate relativistic boost to COM frame from two arbitary velocities?

3 votes
2 answers
386 views

Why does a stationary force affect the conservation of momentum, but not the conservation of energy?

3 votes
4 answers
220 views

Is there a space-like equivalent of the Twin Paradox?

3 votes
1 answer
116 views

How can one define a covariant rate of change of rest mass for an extended body?

2 votes
2 answers
118 views

Can an accelerated spring in static equilibrium in its rest frame have different forces at each end?

2 votes
2 answers
106 views

Must the varied paths in the action be physically possible?

2 votes
3 answers
95 views

Does a spring's $k$ affect the acceleration of a coupled mass?

2 votes
2 answers
131 views

QM probability density function without Born's rule, invariant to wave-function phase

2 votes
3 answers
831 views

Can the Euler-Lagrange equations be derived from an infinitesimal Principle of Least Action?

2 votes
1 answer
151 views

Why does Dirac write $\langle\xi'|\overline{f(\xi)} = \overline f(\xi ')\langle\xi'|$?

2 votes
1 answer
91 views

How does Dirac show that $\langle B|\bar{\bar{\alpha}}|P\rangle\;=\; \overline{\langle P|{\bar{\alpha}}|B\rangle}\;=\; \langle B|{\alpha}|P\rangle$?

2 votes
1 answer
121 views

If time-like paths are geodesics, what physical principle applies to space-like intervals?