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location Greece
age 74
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Retired experimental particle physicist.

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


14h
revised What does temperature look like at the subatomic level?
additional explanation after comments
16h
comment What does temperature look like at the subatomic level?
continued: for the very small time interval where the ion ion elementary interactions take place.
16h
comment What does temperature look like at the subatomic level?
This is a hypothesis, as is the quark gluon plasma that is being studied now at LHC. One has to hypothesize degrees of freedom for the quarks and gluons so that a temperature can be defined. This is supposed to happen at the early stages of the Big Bang, where the energy of the universe is concentrated in a small volume, and all hypothetical particles are hypothesized free within that volume so a hypothetical temperature can be defined. For quark gluon plasma in the lab the gluons will never be seen but the resulting distributions are expected to be explained by the hypothesis of a plasma
16h
answered What does temperature look like at the subatomic level?
17h
answered How can a detector distinguish between a photon and a gluon
1d
comment Why is fundamental physics taught in terms of particles?
If you want contact with nature and not to remain in the realm of mathematics,i.e. if you want to model the physical reality, then particles are what nature offers for measurement and observation.
1d
answered Is the plasma state always visible?
1d
answered How “unnatural” is the universe?
1d
answered In scattering, how does a particle 'know' which direction it is being illuminated from?
2d
comment About Quantum Mechanics
Well, in my book, they have been ruled out experimentally by the great multiplicity of experiments that validate special relativity. One cannot have a fundamental theory violating special relativity.
2d
comment About Quantum Mechanics
as far as I know all the serious hidden variable theories for quantum mechanics either violate special relativity or are just a more complicated mathematically way of doing the same calculations. For example the pilot wave Bohm theory can only work in first quantization levels, not in second quantization. And special relativity has been proven with a lot of measurements so to say there is no experimental evidence so far is stretching the truth. Hidden variables cannot accommodate SR.
2d
answered Why was theory of cosmic aether discarded?
2d
answered Extracting heat energy without a heat engine
2d
comment Why are magnetic fields so much weaker than electric?
Thus when an EM wave impinges on an atom it will often see the poles of the electrons, whereas the magnetic can only interact with the magnetic dipoles of the atoms etc.which are much weaker. That is why the electric is more important, even though the energy carried is the same, as Johannes states.
2d
comment Why are magnetic fields so much weaker than electric?
Keep in mind the weakness of the electric dipole field too. The magnetic field we observe from magnets is a dipole field, so will certainly be weaker than the direct field of a pole, which is what is at play in atoms etc. It is the electric field potential that plays the leading role.
2d
comment Evidence of why the Standard Model is a successful theory of particle physics
@RBarryYoung It might demand,( as the holy trinity demands), but it is first and foremost an experimental fact that has to be accommodated in any theory at a basic level. It is a foundational experimental fact.At the moment it is in the postulates, we have SU(3) from the data. It could be that a theory of everything would come out with "why SU(3)" , for example that all other SU groups would involve strong cavitations and non existence of protons and neutrons thus back to the anthropic principle: "for us to exist, SU(3) is necessary". Until then general features measured are in the postulates.
Jul
28
comment Evidence of why the Standard Model is a successful theory of particle physics
@RBarryYoung Physics does not answer "why" questions . In particular a successful physics model shows "how" from assumptions, postulates, mathematical axioms and formulations, the known data can be classified and new phenomena predicted. The three generations are an observational fact and are counted within the postulates of the standard model.
Jul
28
comment Evidence of why the Standard Model is a successful theory of particle physics
Fine, go ahead, it is a good answer
Jul
28
comment Evidence of why the Standard Model is a successful theory of particle physics
on failures: it cannot explain the large CP violation seen in cosmology ( baryon universe)
Jul
28
revised Physical reason why (hot) objects glow?
clarification after comment