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Nov
13
comment Do the particles made in a collider exist outside the collider?
@AlfredCentauri I think Zeynel is using "electric and magnetic fields" to mean "electric and magnetic fields of a very high intensity, as found inside a collider." In that case it makes perfect sense to talk about turning them off.
Nov
13
comment How many bits are encoded on the surface of the smallest black hole?
I think the assumption of Euclidean geometry will be violated in quite an extreme way, because a tiny black hole will be a very highly curved region of space-time. My own wild guess is that the smallest black hole will have an entropy of one bit, and therefore a surface area of four Planck areas -- but I have no idea if that is correct. It's an interesting question: +1.
Nov
13
revised Motivation for the use of Tsallis entropy
corrected error, changed title, made small improvement.
Nov
13
comment One way insulation?
To concur and clarify slightly: it's the second law of thermodynamics (increasing entropy) that would be violated, not the first law (conservation of energy). You could use it to build a "perpetual motion machine of the second kind", which converts heat at a single temperature into usable energy, but not a "perpetual motion machine of the first kind", which creates energy from nothing.
Nov
13
asked Motivation for the use of Tsallis entropy
Nov
13
comment Does unitarity imply conservation of energy?
I'm not sure I understand your comment. Didn't I already show that describing the time evolution (as unitary and time-independent) implies the Schrödinger equation?
Nov
9
awarded  Popular Question
Nov
8
comment Thermodynamics and cross entropy
@EmanueleLusio in general yes, it can be different. It's because the waste heat from the heat engine has to go into the heat bath. The temperature if the waste heat bath determines the maximum efficiency of the engine, which is different in the two cases.
Nov
7
comment Thermodynamics and cross entropy
@EmanueleLuzio it's because the heat baths don't play symmetrical roles: we put the system first in contact with one and then the other. If we did it in the opposite order the maximum work would be $T_1D_{KL}(Q\|P)$ instead.
Nov
7
answered Does unitarity imply conservation of energy?
Nov
5
awarded  Convention
Nov
4
comment does the beam of a laser have 'throw'?
@aufkag no I can't, but I can correct the silly mistake in my answer. (Done - thanks.)
Nov
4
revised does the beam of a laser have 'throw'?
added 12 characters in body
Nov
4
comment Impulse Response and Linearity
A request for clarification: are you asking how to get from the equation ($y(F_1(t))+y(F_2(t))=y((F_1+F_2)(t))$) to the diagram, or are you asking for the justification behind the equation?
Nov
4
answered If an object fell from the moon
Nov
4
revised does the beam of a laser have 'throw'?
noted an interesting consequence, minor improvements
Nov
4
revised does the beam of a laser have 'throw'?
noted an interesting consequence, minor improvements
Nov
4
answered does the beam of a laser have 'throw'?
Nov
4
revised How long does it take for a chemostat to reach equilibrium?
added 151 characters in body
Nov
4
revised conservation of momentum when a bullet hits a block
please don't shout