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Retired experimental particle physicist.

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


Jul
14
comment Do particles with exactly zero energy exist?
The strong force gets stronger the smaller the energy, is more attractive.zero mass glue glue would glue to each other with numerous bound states approaching zero energy and I do not know what would happen at the exact zero. these glue balls have not been seen except with jets at high energies.
Jul
14
comment Do particles with exactly zero energy exist?
No, the Hilbert space is a mathematical space extremely useful for describing nature. It does not define nature. If a theory based on this hilber space included that, i.e. the lagrangian whose solutions give the standard model, it would be a falsified theory because the data falsifies it.
Jul
14
comment Do particles with exactly zero energy exist?
In the SM mathematics a zero mass zero energy gluon is a singularity and on the lines of Lubos' answer linked above in a comment, it would have been observed if it existed !!!.
Jul
14
comment Do particles with exactly zero energy exist?
My comment means that data trumps theory (physics), philosophy expects theory to form the data. As I tried to show in my example with the expansion in a series fitting an object, the mathematics does not form the object , it just fits it as a tool to be able to enter it in a computer, for example, or another calculation. Those series components are virtual, they have no physics status.
Jul
14
comment Do particles with exactly zero energy exist?
You are thinking on platonic lines, i.e. mathematics defines nature , (philosophy) and not nature is modeled with mathematical functions/theories ( physics)
Jul
14
comment Do particles with exactly zero energy exist?
Those are mathematical constructs, virtual, very useful in calculating measurable cross sections etc. but not physical/measurable. They are a necessary part of a mathematical model . Take a complete set of functions and fit a three dimensional shape to high accuracy, a real ball as an example. Does it mean that the ball is built up by the fourier( or what not) components that go to infinity?
Jul
14
comment Do particles with exactly zero energy exist?
both energy and momentum zero leaves no object for measurement. Just space time points. (0,0,0,0) is an origin not a particle
Jul
14
comment Do particles with exactly zero energy exist?
In special relativity all zero mass particles move with velocity c, and E^2-p^2 =0, (the mass). special relativity is validated innumerable times in the lab.
Jul
14
comment Do black holes violate the Uncertainty Principle?
The uncertainty principle will make singularities irrelevant as a mathematical point, but macroscopically it will fit the general relativity mathematics of a singularity, that is when gravity is consistently quantized within a larger framework. At the moment quantization of gravity is an effective theory for specific situations/ boundary-conditions
Jul
14
revised Why do the waters of the different oceans of the world have different ratios of their H and O isotopes?
clarification
Jul
14
answered Why do the waters of the different oceans of the world have different ratios of their H and O isotopes?
Jul
14
answered Do black holes violate the Uncertainty Principle?
Jul
13
comment Why are heavier nuclei unstable?
see the chosen answer here physics.stackexchange.com/questions/9098/…
Jul
12
answered Where does mass come from in pair production?
Jul
11
comment Has a double slit experiment ever been done using a track chamber or even contemplated?
The advantage of a bubble or cloud chamber is that if the scatter is large enough it is seen, otherwise the ionization is on average on the theoretical track. It is the de Broglie wavelength that is tiny for particles in the MeV momentum scale that kills the possibility. You have more or less nailed it.
Jul
11
comment Conservation of energy when focusing black body radiation on another black body
I believe your basic misunderstanding is in the limit you put T_r to the sphere. The limit is not a law. It just means that it will melt at that temperature and the geometry will be destroyed as far as absorption and radiation goes so the relevance of conservation of energy is lost.
Jul
11
accepted Has a double slit experiment ever been done using a track chamber or even contemplated?
Jul
11
awarded  Curious
Jul
10
awarded  Nice Question
Jul
10
comment Has a double slit experiment ever been done using a track chamber or even contemplated?
@CuriousOne People are still doing which way experiments, like this one phys.org/news/… . If it could be done ( dx dp allowing with available energies and detector medium) it would be definitive