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Feb
1
revised Possible confusion, the inertia of something yields a tensor? (trying to understand an example)
minor blue pencil stuff
Feb
1
revised Possible confusion, the inertia of something yields a tensor? (trying to understand an example)
added 1 character in body
Feb
1
answered Possible confusion, the inertia of something yields a tensor? (trying to understand an example)
Feb
1
comment What will happen if we collide electron with any quark?
"Is this collision possible?" Happens all the time at facilities like JLAB (and the planned electron-ion collider). It's one way to study nucleon sub-structure. But if you "don't know about energy scales" then this question is unreasonable broad. Many of the same sorts of things are possible as in hadroic cases, but the signals are usually purer.
Feb
1
comment How does Loop Quantum Gravity describe particles?
Surely you should edit your earlier question on the same subject rather than re-positing, no?
Feb
1
comment Does this count as a proper derivation of the formula for work and kinetic energy?
This has much in common with the usual algebra-based approach, my only critique would be that the focus is on symbol manipulation instead of talking about the meaning of what you're doing (and that's a style issue rather than something fundamental). "Serious" treatments use calculus, because it makes it explicit that you don't need periods of constant acceleration, but again that's a nitpick.
Feb
1
comment How do radio antennas follow electrical rules
"However current requires a complete circuit to 'flow'." Is only true over sufficiently long time scales. The antenna works with inputs that are fast compared to the time scale over which that rule applies to it. You can't treat it as a circuit in the sense that you do "circuits" in a introductory course. (The time scales thing even trips experts working in domains they're not used to, BTW. There are special rules at very high frequencies that other EE's stumble on all the time.)
Jan
31
comment Can Quantum Field Theory be right even though it doesn't include gravity?
Well, there is the little matter of the best agreement between prediction and measurement anywhere in science. But perhaps that's just a fluke or something.
Jan
31
comment What influence has the distance of the moon on the height of the tides?
The timing of the tides is mostly down to the Earth's rotation. Moving the moon out would barely affect their frequency (which is currently a shade less than twice a day, and would then be a slightly smaller shade less than twice a day).
Jan
31
comment Boeing 737 Homework Problem
Showing effort has never been the criteria for topicality on Physics SE. And yes, I know there are commenters who suggest that it is, but they are in conflict with the policy as voted by the users. See meta.physics.stackexchange.com/a/5959 meta.physics.stackexchange.com/a/5962 for the policy currently in effect and meta.physics.stackexchange.com/q/7407 for the on-going discussion.
Jan
31
comment Why does quantum mechanics produce different predictions for Bell test experiments than classical mechanics?
"if the theory is proved , we must see quantum cryptography running on all the clouds , banks, etc" Er ... doing it in the lab and commercializing are very different things. You overstate your case.
Jan
31
comment Boeing 737 Homework Problem
This seems to be a "check my work problem".
Jan
31
comment Why does quantum mechanics produce different predictions for Bell test experiments than classical mechanics?
You've already read the kind of shortened, condensed and simplified version you're asking for and it didn't help because the idea is subtle. Thus, my usual comment to the effect that you're not going to get it until you do the math for yourself.
Jan
31
comment Where do photons go when they are absorbed?
You don't do it in the rest frame: that's absolutely the hardest way. You do it by finding a way to know it's energy and then measuring it's momentum in a magnetic spectrometer.
Jan
31
comment Where do photons go when they are absorbed?
By "mass" I (and every other particle physicist) mean the invariant mass. That's my point, electrons gain energy but their invariant mass doesn't change, which contradicts your construction immediately, because binding more energy to the electron would change its invariant mass.
Jan
31
comment Where do photons go when they are absorbed?
Not even wrong. Recall that electrons can interact with photons whose energies are on the scale scale of the electron mass, but in doing so the electron retains the same mass.
Jan
31
comment Photons Disappear and Reappear from Atoms?
In the case of the comment above "unusual" means "not even wrong".
Jan
31
comment Big Bang Quarks Travelling at Light Speed
There are at least two problems with what you've done here. First, from a strict point of view you are in violation of the license agreement here. You haven't said where you got this nor from whom in a way that satisfies the license. Second it represents and attempt gain by simply coping another users contribution which is gauche to say the least.
Jan
31
comment Which charge actually moves to constitute current? Positive or negative?
Related: physics.stackexchange.com/questions/17109/… In particular, not that while built circuits made of meta have negative charges in motion there are more than a few cases where positive charges are in motion (internal to some batteries, in some biological systems, ...).
Jan
31
comment Understanding this metaphor involving e-mails, chaos and phase transitions
There are at least three distinct metaphors there, and they are badly mixed, inconsistently used and not very well thought out from a physics point of view. It just means that at some point handling email dominates your time and you get no actual work done. In the end, however, I don't think this is a physics question at all. You were given poor advice.