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236147
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location Greece
age 74
visits member for 4 years, 2 months
seen 27 mins ago

Retired experimental particle physicist.

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


Mar
24
answered Can we generate electric current by injecting electrons into a copper panel
Mar
23
comment How do atoms in a solid “communicate” force to each other?
keep in mind that one mole of matter comprises of order 10^23 molecules/atoms
Mar
23
comment How do atoms in a solid “communicate” force to each other?
Compressibility is a collective phenomenon, emergent on a large number of atoms, like pressure, and one level up from the atomic level. The basic atomic level interacts with electromagnetic forces. Large collections of atoms display compressibility, as a shorthand of describing zillions of atomic electron orbitals.
Mar
23
answered How do atoms in a solid “communicate” force to each other?
Mar
23
comment Does big bang have really any justification while we are living within a huge chaos?
Physics is described by a sequence of models, modeling different frameworks :the atomic with quantum mechanics, the nuclear with nuclear models, the behavior of large scale with statistical mechanics from which the thermodynamic laws emerge. Each framework has a region of validity for predictions and can be demonstrated to emerge from the underlying level. Deterministic chaos theory does not invalidate thermodynamics. It is an extra tool in predicting collective behavior of complex system, applicable wherever deterministic equations model data.
Mar
23
comment Double slit experiment where the “particle” is a macroscopic capsule with people inside
You have to realize that the grand majority of quantum mechanical effects appear at the nanometer level. This is mainly due to the smallness of h, the planck's constant, which enters in all quantum mechanical solutions. Macroscopic manifestations happen with very special initial conditions, as in superconductivity and superfluidity.
Mar
23
comment LHC: Irreproducible results: when/where else have we put so much trust in one test facility?
Please keep your sense of cost into perspective: the total cost of the LHC is comparable to a cost of an airplane carrier , of which the US has several. A boat can sink and the investment is lost for the future. The LHC data will be studied for decades. (there are still papers coming out of LEP data) In addition LHC is built with the financial contribution of many countries.
Mar
23
comment How does the nature of nuclear force change between attractive or repulsive based on distance?
@RobJeffries can you give a link that explains this? The repulsion comes from a combination of quantum number conservation and electromagnetic forces between quarks, I would think. Not the strong force which spolls over as a nuclear force at the level of nucleons
Mar
23
comment Is it possible to calculate the information content of matter? How?
When you are thinking of total energy, water or nuclei or electrons are irrelevant in that the same states can be reached with creation and annihillation and radiation. What the existence of quantum numbers that identify individual states does is to pick up a subsystem of the total potential in number of degrees of freedom.
Mar
22
awarded  Nice Answer
Mar
22
comment Hawking Radiation: how does a particle ever cross the event horizon?
"But the virtual pair production violates energy conservation" No, the energy to bring the virtual to on shell is provided by the gravitational field , that is why the black holes will finally evaporate.
Mar
22
comment Are double-slit patterns really due to wave-like interference?
@user36790 Just saw this. I cannot judge out of context. The probability wave gives the probability at a given energy and momentum to be found at (x,y,z) or at a given (x,y,z) to have a given energy and momentum. I would not call it transport, except maybe statistically. A wave in water transports energy continuously, not probabilistically. In QM the quantum numbers follow the particle. You cannot go wrong by thinking of the function as a mathematical solution of S equation which fits statistical data.
Mar
22
awarded  Revival
Mar
22
answered Why do we lift our feet when we walk?
Mar
21
answered Evolution and the arrow of time
Mar
21
awarded  Revival
Mar
21
comment How can a magnetic field accelerate particles if it cannot do work?
@SHYAMANANDANINGOMBAM the formulas have been derived to fit experimental observations. That is the way nature is.
Mar
21
answered Quantum hadrodynamics
Mar
21
revised Quantum hadrodynamics
added 536 characters in body
Mar
20
revised What is the meaning of phenomenology?
clarification