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348179
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location Greece
age 75
visits member for 4 years, 7 months
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Retired experimental particle physicist.

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


May
29
comment Single photons: Is there a 90° offset of the electric to the magnetic component in the direction of propagation?
nevertheless the collective action emerges as +/- 1 . You have to acquire a quantum mechanical intuition/view. Classical does not work with elementary particles, and the photon is an elementary particle. if you do not worry about photons, the classical description is fine. you cannot fit the photon into a classical description except as a collective effect, as shown in the link in the answer.
May
29
comment Single photons: Is there a 90° offset of the electric to the magnetic component in the direction of propagation?
The photon does not need a medium
May
29
comment Single photons: Is there a 90° offset of the electric to the magnetic component in the direction of propagation?
@HolgerFiedler Have a look at this quantized form of circular polarization en.wikipedia.org/wiki/…
May
29
comment Single photons: Is there a 90° offset of the electric to the magnetic component in the direction of propagation?
@HolgerFiedler The diagram is the macroscopic effect, the cause is the individual photons, and you cannot assign an E and B field to a single photon because the E and B fields emerge from the ensemble of photons, there is no quantum of electric field or magnetic field . The diagram shows the macroscopic wave, not a photon, which is a point elementary particle. It is putting the cart in front of the horse.
May
29
answered Single photons: Is there a 90° offset of the electric to the magnetic component in the direction of propagation?
May
28
answered What will happen when “earthing” is not an option?
May
28
comment Why is absolute zero considered to be asymptotical? Wouldn't regions such as massive gaps between galaxy clusters have temperatures of absolute zero?
@NicolauSakerNeto superconductivity is a quantum mechanical emergent phenomenon of the electromagnetic fields, i.e.photons
May
28
comment Why is absolute zero considered to be asymptotical? Wouldn't regions such as massive gaps between galaxy clusters have temperatures of absolute zero?
@Kevin Yes, you are making that mistake. The number of photons is proportional to the energy in the region from E=hnu . Only infinite energy will give an infinity photons.
May
28
answered Why is absolute zero considered to be asymptotical? Wouldn't regions such as massive gaps between galaxy clusters have temperatures of absolute zero?
May
28
comment Why is absolute zero considered to be asymptotical? Wouldn't regions such as massive gaps between galaxy clusters have temperatures of absolute zero?
Sorry nitpicking , but the the black body temperature at the time of separation fof CMB was about 3000k , less than what the sun black body is now.damtp.cam.ac.uk/research/gr/public/images/bb_history.gif
May
28
answered Does the Earth gets closer to the Sun?
May
28
comment Justification for new theories of Particle Physics and General Relativity
i.e. can include the standard model of particle physics and all the data known from astrophysics, and then suggest experiments that would differentiate the standard cosmological model from the new proposal. Then the experimenters come in.
May
28
comment Justification for new theories of Particle Physics and General Relativity
@New_new_newbie the experiments are used to validate theoretical models and ultimately validate theories. One can have beautiful theoretical constructs, they are called mathematics. If they do not describe measurable quantities they just remain in the mathematical archives. Sometimes, as with Riemannian geometry, a brilliant choice by a theoretician leads to models that can be validated. So it is not social acceptance, but a slow build up of a theory of everything in nature, by using mathematical models. In the second paper, first theorists have to judge, if it does all it claims
May
27
comment why countries can't make nuclear bombs?
@AlexTwain so that the next generation of terrorists are not carrying nuclear bombs
May
27
answered Why Change Of Magnetic Flux Induces Current In circuit?
May
27
comment Why does hot water clean better than cold water?
addition to answers: for oil and butter the fluidity increases with temperature, which makes it easier to mix with the water and be carried away ( though I would advice some detergent to bind with the oil for good results. It is the kinetic part of Chris' answer en.wikipedia.org/wiki/…
May
27
comment What is the speed of light relative to?
the answers are good. The extra energy given to light by the moving emitter becomes an extra energy in the energy of the photons that compose the light E=h*nu, nu will become larger, the effect of doppler shift on light.
May
27
comment Icecube experiment at the North pole instead of the South?
in the ice whereas the pressures at 4000 meters are tremendous in trying to keep water out of the detectors.
May
27
comment Icecube experiment at the North pole instead of the South?
From the FAQ of the experiment: "The South Pole is the one place on Earth that holds such large quantities of clear, pure, and stable ice and has the infrastructure to support scientific research" note the "and has the infrastructure.." For a water experiment in the depths one also has to build the infrastructure from scratch, from power to the experiment to living quarters or in sity labs for the experimenters. Also sea water (salt) is hard to work with and even at huge depths contains luminous bits of life (they can be programmed against of course). Also it is very easy to make holes
May
26
awarded  Nice Answer