47,326 reputation
229100
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location Greece
age 74
visits member for 3 years, 6 months
seen 4 mins ago

Retired experimental particle physicist.

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


7h
answered How “unnatural” is the universe?
7h
answered In scattering, how does a particle 'know' which direction it is being illuminated from?
23h
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.
1d
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.
1d
answered Why was theory of cosmic aether discarded?
1d
answered Extracting heat energy without a heat engine
1d
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.
1d
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.
1d
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.
1d
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.
1d
comment Evidence of why the Standard Model is a successful theory of particle physics
Fine, go ahead, it is a good answer
1d
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)
2d
revised Physical reason why (hot) objects glow?
clarification after comment
2d
comment Electricity supplication
For islands alternative energy like wind and solar become viable, even without subsidies, if one really wants electricity and is willing to install the infrastructure. At the moment a number of greek islands have independent generators supplied with oil and some have wind turbines
2d
answered What happens when Dark Matter comes in contact with the event horizon of a large Black Hole
2d
answered Physical reason why (hot) objects glow?
2d
answered Are matter waves transverse and can they be polarized?
2d
answered Is the concept of rest mass correct?
Jul
27
comment How does a system interact with environment in quantum mechanics? When would this interaction occur? What is it?
At this level with photon exchanges, there is nothing else long distance acting and as strong, no?
Jul
27
comment How does a system interact with environment in quantum mechanics? When would this interaction occur? What is it?
This does not make much sense, because quantum mechanics is about very small dimensions, and "system" and "environment" are blanket words for large ensembles of particles of these small dimensions. The density matrix formalism has been developed for this purpose. What do you mean by "system" and "environment"?