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236148
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location Greece
age 74
visits member for 4 years, 2 months
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Retired experimental particle physicist.

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


Dec
4
comment Matter Waves Interference
Quantum mechanics is a mathematical formulation that fits all the data of the microcosm we know now . It simplest form is the shroedinger equation whose solutions, instead of giving, for example, orbits for the electron around the nucleus, give orbitals. en.wikipedia.org/wiki/Atomic_orbital . It is the square of the wavefunction that gives a probability of finding the electron in a specific (x,y,z,t). There are no trajectories as in classical orbits for example a satellite around the earth.
Dec
4
answered Matter Waves Interference
Dec
4
answered How does interference move energy from destructive to constructive regions?
Dec
3
comment Capillary action in a slanted tube
@CarlWitthoft Sorry, I would have answered if I had the numbers ready.(It is just a coincidence that I asked a similar question in a lecture today on nanotechnology created channels !) In any case no such choices are given in the question.
Dec
3
comment Capillary action in a slanted tube
If you put in the number , i.e. the mass of the fluid and the attraction of gravity versus the adhesion electromagnetic forces creating the capillary effect you will find that gravity is insignificant. you will need micron accuracy to see the difference
Dec
3
comment Relativity and photon interactions
take the pio particle, it decays into two photons. The center of mass system of the two photons is the CMS of the pion too, i.e. where the pion has zero momentum. Photons interact very weakly with each other through higher order loop diagrams, but that is a long not simple story :en.wikipedia.org/wiki/Two-photon_physics
Dec
3
comment Relativity and photon interactions
Seems to me you are re-thinking the wheel. Better acquire a background on interactions etc. This is a good source: hyperphysics.phy-astr.gsu.edu/hbase/forces/funfor.html . One photon cannot have a rest frame, but two photons can: they have an invariant mass that can define a rest frame.
Dec
3
comment What are the borders of determinism?
Well, nobody has shown it can be done, up to now. I believe that is where all deterministic models fall flat, and also models of discrete space and time though it is just my impression from discussions on the web.
Dec
2
comment Dimensions of strings in string theory
I am just extrapolating from the example of how a circle, which in cartesian coordinates is two dimensional can be described by a single independent variable. It is the independent variables that define the dimensions. Maybe a more mathematically inclined contributor will answer your question rigorously.
Dec
2
answered Dimensions of strings in string theory
Dec
2
answered How can spatially extended objects behave like point particles?
Dec
2
comment What are the borders of determinism?
@jinawee the comment above is also for you :)
Dec
2
comment What are the borders of determinism?
Bohmian mechanics cannot be carried out to agree with special relativity so it is out of the game: special relativity is crucial for any interpretation of particle experiments. Generally deterministic theories are toy models and fall down when special relativity needs to be imposed, as far as I know plato.stanford.edu/entries/qm-bohm.
Dec
2
comment What are the borders of determinism?
@Christoph and Jinawee why don't you both look up my age? 73 . I started with machine language in 1967 and ended with C++ by retirement. I may be permitted to stop learning new computer tools at retirement, I hope? I am grateful to anybody replacing with nice symbols . Thanks.
Dec
1
answered What are the borders of determinism?
Dec
1
revised Why is the decay of a neutral rho meson into two neutral pions forbidden?
edited body
Dec
1
revised Why is the decay of a neutral rho meson into two neutral pions forbidden?
added 2 characters in body
Dec
1
comment Is it possible that only one hemisphere of a planet has an atmosphere?
This assumes that an atmosphere exists.It all boils down to the boundary conditions of the problem. At 273 ice forms and the planet is not all water, just half of it, with the proviso that that daylight reaches boiling temperatures.
Dec
1
comment Is it possible that only one hemisphere of a planet has an atmosphere?
It is a non rotating planet in the question above, I think. The differences in temperature between night side and day side will be enormous and any atmosphere going by convection to the dark side will freeze out.
Dec
1
comment Is it possible that only one hemisphere of a planet has an atmosphere?
There is a tail to the kinetic energy distribution where the atoms in the tail achieve very large energies and can achieve escape velocity. A calculation is needed to see how long a boiling ocean with a steam atmosphere will last. scientificamerican.com/… main problem with your model is that the oceans will be depleted and end up as ice on the dark side, because there is no new source of water.