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bio website akhmeteli.org
location Houston, TX
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visits member for 2 years, 6 months
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15h
answered Isotropic neutrino-lepton scattering
Jul
18
answered How are the distances to the most distant $\gamma$-ray bursts measured?
Jul
18
comment Why the original BB84 paper “Quantum cryptography: Public key distribution and coin tossing” has 'withdrawn' status?
@dmckee: Maybe I don't quite understand your comment... The DOI points to a 2011 article, whereas the original article is dated 1984 (cs.ucsb.edu/~chong/290N-W06/BB84.pdf ) I don't think the authors published an article with the same title 30 years later. That is why I suspect a reprint was withdrawn, rather than the original article..
Jul
17
answered Why the original BB84 paper “Quantum cryptography: Public key distribution and coin tossing” has 'withdrawn' status?
Jul
16
answered Proper and rigourous derivation of Gaussian beam?
Jul
12
comment How can a gas support tensile stresses?
@Bryson S.: There is no such thing as "too far" in physics, there is only ""too far compared to something". In this case, I guess, you should compare the potential energy of attraction with the kinetic energy. Again, it is not obvious that negative absolute pressure is possible in gases, it is not obvious that it's impossible.
Jul
12
comment How can a gas support tensile stresses?
@Bryson S.: I am not sure if negative pressure is possible for gases, but if it is, the mechanism should be the same: molecular attraction.
Jul
12
answered How can a gas support tensile stresses?
Jul
6
comment Is there Phase difference between voltages at end points of a long AC Power line
@HIMANK: The average electron flow in the wire is determined (mostly) by the electric field in the wire, and to calculate the electric field, you need (ideally) to solve the Maxwell equations using appropriate material equations for the wire.
Jul
6
answered Is there Phase difference between voltages at end points of a long AC Power line
Jul
6
answered How can I calculate the relative permeability of iron?
Jul
5
comment How can one explain the Kelvin Water drop experiment without assuming the container to already possess a positive charge?
I don't think one can measure charge in Farads.
Jul
5
comment Bulk flow of air in a long tube between Antarctica and Australia?
I would say the wording of the question strongly suggests that there is no insulation - it mentions a "clear plastic tube". Plastic's thermal conductivity is not very low, and insulation is typically not transparent, so if there were some extra insulation, saying that the plastic is "clear" would not make sense.
Jul
4
reviewed Leave Open Cooling induction current generation
Jul
4
reviewed Leave Open Can we pass electricity through air?
Jul
4
reviewed Leave Open Collision of light waves & matter
Jul
4
answered Can we pass electricity through air?
Jul
1
comment How do you levitate a foam rock? ('Endless Second' artwork)
@user52453: OK, I I did not realize that. I cannot derive a stable configuration. I can only give the following reference: B.V. Jayawant, "Electromagnetic Levitation and Suspension Systems", Publishers: Edward Arnold, London, 1981 (I haven't seen this book myself). I don't know what exactly you're trying to achieve, but maybe you might be interested in the stable equilibrium of, say, a ping-pong ball in an upwards air jet.
Jun
30
comment How do you levitate a foam rock? ('Endless Second' artwork)
@user52453: The following source from the Wikipedia article seems relevant: sprott.physics.wisc.edu/demobook/chapter5.htm . But please don't do anything like that if you don't know exactly what you're doing. I don't want you to be electrocuted. Safety first - the phrase is boring but you better remember it.
Jun
29
comment How do you levitate a foam rock? ('Endless Second' artwork)
@user52453: If you mean to have an alternating current electromagnet, then yes. But finding a stable configuration may be relatively difficult.