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seen Mar 14 at 14:18

Jan
15
comment What is potential energy truly?
One does not need to imagine energy as being stored somewhere. Yeah, it isn't as if the energy density appears anywhere important - like, say, the RHS of the Einstein equations? :p
Jan
14
comment Where is the potential energy saved?
@Sofia: I do not understand your objection; as long as you only bring an arbitrary but finite amount of charges, the potential energy will be finite; anyway, if I recall correctly, the interpretation of potential energy as field energy (once you substract the self-energy of the charge) can be found in chapter 1 of Jackson's EM book
Jan
14
revised Where is the potential energy saved?
spelling: Poynting was a person
Jan
5
awarded  Nice Answer
Dec
23
comment Difference between theoretical physics and mathematical physics?
@Schlomo: it's a joke; Mermin is a well-known theoretical physicist and most likely the person who coined the term "shut up and calculate" as an approach to interpreting QM
Dec
23
comment Independence of thermodynamic variables
sounds good to me (I forgot to mention that at least one variable has to be extensive); also note that you can define conjugate pairs with respect to state functions other than energy - eg the entropy representation
Dec
23
comment Independence of thermodynamic variables
No answers yet? The variables must not be conjugate, and you need to switch from internal energy to the thermodynamic potential associated with your choice of variables...
Dec
22
answered Difference between theoretical physics and mathematical physics?
Dec
22
awarded  Informed
Dec
22
revised Feynman-Stueckelberg interpretation
deleted 1 character in body
Dec
22
comment Feynman-Stueckelberg interpretation
@FredericThomas: see edit
Dec
22
revised Feynman-Stueckelberg interpretation
clarified
Dec
22
comment Does the difference between contextuality, nonlocality and retrocausality depend on where we draw the boundaries?
@CuriousOne: What was missing from Luboš exposition? Without decoherence, the Copenhagen interpretation is more religion than physics. Also note some more steps along the way towards a fuller understanding of QM that happened after the 30s: We got the path integral in the 40s, Gleason's theorem in the 50s, Bell's theorem in the 60s, the Lindblad equation in the 70s, decoherence experiments in the 80s, Shor's algorithm in the 90s, ...
Dec
22
comment Does the difference between contextuality, nonlocality and retrocausality depend on where we draw the boundaries?
@CuriousOne: no contradictions, but fairly important clarifications (your claim was that we haven't learned anything since the 30s); your buddy Luboš has written multiple times about this subject, eg this article (take note of the paragraph Limitations of the Copenhagen interpretation)
Dec
22
comment Does the difference between contextuality, nonlocality and retrocausality depend on where we draw the boundaries?
@CuriousOne: major experiments on decoherence where not performed until the 80s
Dec
22
comment Does the difference between contextuality, nonlocality and retrocausality depend on where we draw the boundaries?
@CuriousOne: Ignoring the part a about retrocausality, the question is if quantum contextuality is a consequence of entanglement with an environment that lies beyond the Heisenberg cut. Makes sense to me...
Dec
21
comment Exploring beyond event horizons
@ReXdean: no; the cosmic horizon is an event horizon, so you have to take into account the time of arrival: the signal emitted at A will reach B at a point in time that lies beyond C's horizon
Dec
21
revised Exploring beyond event horizons
mention horizon
Dec
21
revised Exploring beyond event horizons
formulation
Dec
21
comment Exploring beyond event horizons
note that recession velocities reach $c$ at the Hubble sphere, whereas relative velocities according to parallel transport along the light ray will reach $c$ at the cosmic horizon, so in a way, the horizon is where 'relative veocities' reach speed-of-light; it's just that if spacetime isn't flat, you have to be careful about what you mean by 'relative velocity'