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May
4
comment Is there a simple layman way to explain the incompatibilities between quantum mechanics and (general) relativity to high school students?
I'd settle for a simple way to explain it to advanced undergrads.
May
4
comment regarding the infinite cross section in Rutherford scattering
This is true, but in a sense uninteresting when you put real beams on real targets. In that cases there are many scattering centers in the target and the actual scattering is dominated by the closest scattering center, meaning that the small angle scattering fades smoothly into the multiple scattering regime.
May
3
comment Pendulum Confusion
They mean that in real life you get a smallish, heavy mass on a light and reasonably inextensible string which is only almost the same as the idealized model. You are also generally assuming no frictional losses at the pivot when the real cases is very small frictional losses. This is entirely similar to learning projectile motion in a vacuum to get used to the math.
May
3
comment If a neutrino has a rest frame, why can't a photon have a rest frame as well?
The mass limit exhibited by @GigiButbaia is very much obsolete. That limit is from direct observation of beta decay kinematics, but cosmological observation put strict limits on the sum of the masses of the neutrino species that are much less than 1 eV.
May
3
comment Does this* refraction experiment correctly conclude faster than light travel?
"its a very engaging 35 minutes. watch it." So, you want people to not only help you out but to invest more than half-an-hour or their time before they can even begin? And you can't even be bothered to describe the set up here? Really?
May
3
comment Mass eigenstate of neutrinos
@cppinitiator The "mass of a particle" means (in modern parlance) the Lorentz invariant mass (you may know it as the "rest mass"). There is nothing wrong with the idea of relativistic mass as such, but significant parts of physics have deprecated the term. Particle physics is one of those areas.
May
3
answered Relativity conclusions from Michelson-Morley Experiment
May
2
comment Particle Physics : Conservation laws
Even the overall conservation of lepton number fails if neutrinos are Majorana particles (a fact not yet known but beginning to look less likely). After all, the signature event for determining that is neutrinoless double beta decay.
May
1
comment Why is the absolute zero a rational number in Celcius?
Note that the speed of light is now and integer when expressed in SI units. Think about how that came to be. Metrology is an interesting business.
May
1
comment Electromagnetic factors affecting inertial mass of a body affect its gravitational mass or not?
All shouting comments have been removed.
May
1
comment Do photons occupy space?
@Godparticle Part of the trouble here is that laymen look at, say, Compton scattering and say "Ah ha! They collided", but the math that describes that interaction doesn't have a "thing-hitting-thing" character, it has a "the-field-of-a-thing-affecting-the-other-thing" character. That's what DavidZ keeps saying "interact" not "collide". Interaction does not imply extent.
Apr
30
comment Why does acceleration seem not to be the gradient of gravitational potential?
@zhermes Potential differences can be integrated from anywhere. To get the potential directly from the integral without a correction term you integrate it from where it is defined. In the case of the usual gravitational potential that definition is zero at infinite remove.
Apr
30
comment Dropping a ball in a train moving close to the speed of light?
@brightmagus In these units velocities are dimensionless and $c$ has magnitude 1. Day to day velocities you are used to dealing with are around $10^{-7}$ to $10^{-9}$.
Apr
30
answered Dropping a ball in a train moving close to the speed of light?
Apr
30
comment Dropping a ball in a train moving close to the speed of light?
@DavidZ The reason he's re-asked in this formulation is me and my big mouth. And now, I'm forced to think carefully again. Stay tuned.
Apr
30
comment Can you give example of some problems with solutions in each of Newtonian, Lagrangian and Hamiltonian method?
Please do not edit answers into questions. That is not in keeping with the model we use here.
Apr
30
revised Can you give example of some problems with solutions in each of Newtonian, Lagrangian and Hamiltonian method?
rolled back to a previous revision
Apr
29
comment Velocity measurement in relativistic perspectives
Please take extended discussions to chat.
Apr
29
comment Can you give example of some problems with solutions in each of Newtonian, Lagrangian and Hamiltonian method?
The proper state of this question is under discussion on meta.
Apr
28
revised Why does this object periodically turn itself?
Note a dead link, and insert a more general reference