68,448 reputation
348180
bio website
location Greece
age 75
visits member for 4 years, 7 months
seen 1 hour ago

Retired experimental particle physicist.

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


May
3
revised Why do grey body radiators not heat up?
added second important reason for changes in temperature ( incoming energy).
May
3
comment Why was quantum mechanics regarded as a non-deterministic theory?
If it is correct, it is another isomorphic construct of quantum mechanics (like bohmian qm). I have not heard of any predictions being verified or even tested.Anyway, "collapse", "entanglement" are, imo, fancy words to describe what are simple mathematics and measurement interpretation rules and leave me indifferent.
May
3
comment Why was quantum mechanics regarded as a non-deterministic theory?
Lets stop this. You are completely wrong, the schrodinger picture is a probabilistic picture because it is a quantum mechanical theory. It determines the state function, not the measurable quantities, which are given as probability distributions.
May
3
comment Why was quantum mechanics regarded as a non-deterministic theory?
No, the schrodinger picture gives a probability of finding any measurement value, not a fixed value of the momentum. One has to operate on the schrodinger state function, with the momentum operator to get the momentum, and the operation.measurement will give a value within the probability envelope.
May
3
comment Why was quantum mechanics regarded as a non-deterministic theory?
The HUP is a postulate incorporated into the mathematics of commutators.
May
3
comment Why was quantum mechanics regarded as a non-deterministic theory?
When measuring one particle's x then going to the next, their momentum will be indeterminate and "next" will have a whole phase space to be chosen from because momentum determines the next probability of x, not a point but a probability of being found at that point, whether 1 2 3 or infinite number of particles.
May
3
comment Why was quantum mechanics regarded as a non-deterministic theory?
You are wrong. The HUP is not optional. The total universe obeys the HUP postulate so as far as the theory of quantum mechanics goes, which is what you are asking, it will always be indeterminate by construction of the theory. It was constructed to fit observations and if you extrapolate to the total universe it makes no difference. (You said you are not considering other theories )
May
3
answered Why do grey body radiators not heat up?
May
3
answered Why was quantum mechanics regarded as a non-deterministic theory?
May
3
comment Whether nuclear physics or nuclear engineering is suitable for doing research in nuclear fusion?
There exist centers where fusion is studied in tokamaks or inertial confinement fusion ( life.llnl.gov ). Fore example in llnl it seems they collaborate with universities and the experiments are done at the lab. lawrence-scholar-program.llnl.gov/selection.php .
May
2
answered How do molecules bubble off a photon?
May
2
answered Where does the energy for magnetizing a metal come from?
May
1
comment Can someone please explain magnetic vs electric fields?
@Val the above comment is also addressed to your comment which I just noticed today.
May
1
comment Can someone please explain magnetic vs electric fields?
@Benjohn As an experientalist it seems simpler to me to anchor my understanding on the data, which is how I have answered this question. Now once one has a theory that fits the known data and predicts accurately new experimental situations, one can use any type of isomorphic assumptions, use the mathematics and get the same results. This is the case of just using charges and the Lorenz transformation to express the predictions for measurements. This does not eliminate electric and magnetic fields, just describes them in a different basis.
May
1
comment How do the single photon energy and em-signal energy correlate?
Well, it is an emergent phenomenon that is anchored both in the micro world and in the macroscopic world on Maxwell's equations. The classical is built up "lego like but with complicated mathematical contortions" from the quantum mechanical one. In the macroworld we do not need to refer continually to the micro quantized framework, because of the continuity given by the maxwell equations. the classical wave is sufficient for most situations.
May
1
comment How do the single photon energy and em-signal energy correlate?
The energy of the electromagnetic wave is the sum of the energies of the photons composing it. The classical amplitude is built up from the ensemble of photons consistent with the Maxwell equations . see motls.blogspot.com/2011/11/…
May
1
revised Do COBE, WMAP, or Planck data show time-variance of the CMB's anisotropies?
added 308 characters in body
May
1
comment Do COBE, WMAP, or Planck data show time-variance of the CMB's anisotropies?
I want also to note that your edited question changes drastically the pov. You were talking of hubble time and that is the content of my answer.
May
1
comment Do COBE, WMAP, or Planck data show time-variance of the CMB's anisotropies?
the answer linked as duplicate addresses your edited question. In a hundred years maybe some variation might be detectable , is my summary.
May
1
comment Do COBE, WMAP, or Planck data show time-variance of the CMB's anisotropies?
as far as the map goes the anisotropies are seen at a fixed time t when the data were taken. It is a photograph, a snapshot, of the time when radiation decoupled. So to get time changes you would have to estimate the radius of the universe at that time (see for evolution of universe abyss.uoregon.edu/~js/cosmo/lectures/lec20.html ) at 500.000 years . You could estimate the delta(t) for the anisotropies by dividing the hubble radius with c. It is not usually done because it carries no information other than whether the regions can communicate or not.