55,970 reputation
234128
bio website
location Greece
age 74
visits member for 3 years, 11 months
seen 7 hours ago

Retired experimental particle physicist.

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


Dec
17
comment Why can't dark matter be baryonic?
Have a look at pdg.lbl.gov/2014/reviews/rpp2014-rev-dark-matter.pdf .
Dec
17
comment Why can't dark matter be baryonic?
I am curious, my first impulse would be that baryonic matter would contain charged particles and charged particles interact electromagnetically. Neutral ones are either in atoms, and they also interact and give spectral lines, or unstable. One hypothesizes exotics for dark matter just because in contrast to baryons, electromagnetic interactions are higher order and less probable.
Dec
17
comment Birds and cables: how is the potential difference between two diff. cables established?
Birds usually sit on one cable. If the birds are large enough to touch two live wires they set themselves on fire. My son did his army duty at an outpost where three times crows shorted two cables and set fire to the forest and the soldiers had to rush and put it out. Now in Greece they are slowly replacing the four cables into one braided one and insulated for this reason ( trees too can short two wires)
Dec
17
answered At what point do researchers in physics make the leap from wild theoretical ideas to physical experiments?
Dec
17
comment Schroedinger Equation and Special Relativity
@joshphysics I guess it is the first order derivative in time that does not allow to see the relativistic form while the KG has it explicitly.
Dec
17
comment Schroedinger Equation and Special Relativity
@joshphysics yes, the mass is non relativistic and it is hard to see what would happen at relativistic energies . So I guess my "no" in the answer above is centered on that, as well as the statement in the wiki article. in the KG you know you are dealing with the rest mass.
Dec
17
comment Schroedinger Equation and Special Relativity
@joshphysics I am not disputing QFT. I want a simple demonstration that the S equation is relativistic; I think that the Klein Gordon is the relativistic version of the S. at least the article in wikipedia must also be wrong then.
Dec
17
comment Schroedinger Equation and Special Relativity
@joshphysics the closer I got by searching that the former is relativistic was " it is hard to show that it is" . Do you have a link . I was always of the impression that one needed the Klein Gordon for this , even without spins. ?
Dec
17
comment Schroedinger Equation and Special Relativity
@joshphysics I am assuming the garden variety equation.
Dec
17
revised Schroedinger Equation and Special Relativity
added 134 characters in body
Dec
17
answered Schroedinger Equation and Special Relativity
Dec
16
awarded  Revival
Dec
16
comment The mass of universe at the point of the Big Bang
@CuriousOne the uniformity of cosmic microwave background radiation could not be explained in the Big Bang. At that time when photons separated the universe could not come to thermodynamic equilibrium because of space time limitations. That is why they invented the inflaton field, to homogenize everything.
Dec
16
comment Simple explanation of quantum mechanics
@rosey if you see this, the link where you might get a review is at physicsoverflow.org .
Dec
16
revised Transfer of electron energy to atoms (heating up of matter by absorption of photons)
clarification for consistency
Dec
16
revised Simple explanation of quantum mechanics
added 493 characters in body
Dec
16
comment Simple explanation of quantum mechanics
@DanielSank this was answered in march '11, since then I have often included large dimension manifestations of quantum mechanics, including superfluidity, superconductivity and crystals. Since the entry became active today I will edit and include this. Now I am not familiar really with quantum computing sizes so cannot enter into that.
Dec
15
comment QFT and violation of Heisenberg uncertainty principle
@Sofia The very small dt is compatible with very short existence for a virtual particle, but the mass may even be imaginary I think. One would have to look at the integral limits for the specific case.
Dec
15
answered When do we see particles to be in a superposition of energy states?
Dec
15
comment QFT and violation of Heisenberg uncertainty principle
@Sofia you should quote with @ the user you are addressing otherwise they will never see the comment . Well, I can see it as a box volume delta(e)*delta(t) . virtual is within the box and there it is as you say. So it is a constraint on the box, I think. It makes the box an identity, but I would like to see the context ( if it is both larger than and equal and smaller than and equal, it is equal)