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236146
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location Greece
age 74
visits member for 4 years, 2 months
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Retired experimental particle physicist.

The picture is a fayum . It looks like aunts and cousins of mine :).


4h
answered How does the Super-Kamiokande experiment falsify SU(5)?
1d
revised Does big bang have really any justification while we are living within a huge chaos?
deleted 10 characters in body
1d
answered Does big bang have really any justification while we are living within a huge chaos?
1d
comment Does big bang have really any justification while we are living within a huge chaos?
I mean that the fact that a system can obey a dynamical chaos model, i.e. show attractors, as the planetary system does for example, does not mean that one could not follow with a computer the paths of each planet to any accuracy one wished, backwards and forwards.That is how planetariums work . In the Big Bang hypothesis it is the space that is expanding , the simplest modeling for the coordinates of the objects observed. Thus the chaotic part of the content due to the thermodynamics becomes irrelevant to the problem. The BB is accepted because of its economy in hypothesis to fit the data.
1d
comment Does big bang have really any justification while we are living within a huge chaos?
No, I did not mean use classical thermodynamics for the universe from Z to A. I meant that in the appropriate boundary conditions thermodynamics can be used to know what happened at previous time, postdiction. One should be careful of defining the boundary conditions for the physical situation modeled within a framework In my example the framework is thermodynamics.
1d
comment Does big bang have really any justification while we are living within a huge chaos?
@owari It is similar to asking "since thermodynamics describes chaotic systems" there is no predictability in thermodynamics, or extrapolation backwards in time. There are situations, with turbulence, where it is very hard to model with thermodynamics viz the weather predictions. In the BB model this stage happens in the very beginning where it is acknowledged that theory is shaky and other hypothesis compatible or to explaing the data are put forth, like inflatio theory
2d
comment Can the Unruh effect be confirmed by the LHC?
I did think of it, except the interaction crossection calculations already must have this effect in since they use quantum field theory and I believe the vacuum is taken into account. You did give me an idea though. Maybe it is the explanation for the experimental observation of excess soft photons sciencedirect.com/science/article/pii/S0370269302028368 and references therein. A friend of mine has benn working on this for decades in various experiments.
Mar
30
comment Why does this resource say that the Schrodinger Equation can be derived?
one needs the definition of "derive" . The paper assumes quantization and imposes it so that the hbar enters the system. It is not a pure mathematical derivation, but a heuristic derivation, using physics input. In any case it was never published in a peer reviewed journal.
Mar
30
comment Do photons lose energy due to gravitational redshift? If so, where does the lost energy go?
On the link in your edit, I think that the second way is the simplest way in any case, since in the limit, as the gravitational field decreases, the newtonian expectation should arise, with no clocks . No physic, al clock could be following a photon out of the well anyway except another photon, and of course they see each other unchanged.
Mar
29
revised What does the “T” stand for in T-duality?
added 206 characters in body
Mar
29
answered What does the “T” stand for in T-duality?
Mar
29
revised Does radiating heat to outer space through the atmospheric transparency window have any impact on heat loss?
correction, "down to cooling"
Mar
29
comment Can the Unruh effect be confirmed by the LHC?
I do not think they average out, as that they do not have enough energy to change from virtual to real, i.e. be seen on mass shell. crudely the crests and troughs are flat, imo.
Mar
29
answered Can the Unruh effect be confirmed by the LHC?
Mar
29
comment Is dark matter moving faster than light?
please read upe on what is dark matter en.wikipedia.org/wiki/Dark_matter and also contrast it with dark energy: en.wikipedia.org/wiki/Dark_energy
Mar
29
comment Do photons lose energy due to gravitational redshift? If so, where does the lost energy go?
@innisfree you can do the same mathematically in some subsystems of General relativity and this gravitational redshift is one of them. potential energy is a mathematical construct that incorporated into theories gives predictivity, true classically and can be extended to special frames for GR
Mar
29
answered Does radiating heat to outer space through the atmospheric transparency window have any impact on heat loss?
Mar
29
comment How can 99% empty matter have solidity?
The microcosm is not following classical physics extrapolations to atomic level that was discovered experimentally. In Quantum mechanics and special relativity the concept of matter and energy are radically redifined as well as what solid means at that level .
Mar
29
comment Discovery of spin-3 particle at LHCb
It was not the first time. It is the first time in B resonances. please see my answer for the link
Mar
29
comment Do photons lose energy due to gravitational redshift? If so, where does the lost energy go?
@innisfree But this last has nothing to do with general relativity. You are refuting the whole construct of classical mechanics etc too, models that have been extremely successful in predicting new data, not only modeling old.