Why the Photon?

LorentzR

I absolutely agree with ZapperZ's comments on proofs and physics. But his assertion that the Photon has a physical reality is inconsistent with his comments on proofs.

I would think with great difficulty.

A reductionistic theory in which the photon is required to have physical reality would throw the balance of probabilities towards realism. As you say its all made up stuff and does not completely hold together.

LorentzR

I suspect that quantum systems continuously interact with the rest of the universe and are fully connected to the universe we live in.

In order for an observation to be made the effect of an interaction must be amplified into a detectable event. Then there must be somebody there to observer the event.

For a “particle” to have physical reality it must have a universe to interact with and be able to reference the magnitude of its physical states.

LorentzR

We do not have a wholly reductionistic theory modelling one with the other. We depend on the Born rule for quantum mechaics to work.




Quantum mechanics predicts the results.

XVX

There is no metric for the Universe. And certainly, the perihelion of Mercury was not calculated with the Minkowski metric. And unquestionably, GPS systems do not use the Minkowski metric. The Minkowski metric is GR’s special case in which one has Newton’s Laws and a finite speed limit theory that is commonly known as, SR.


But why photons?

Why does matter choose energy in packets?

When EM waves are incident upon Hydrogen, is there some mechanism in Hydrogen that says, “we will wait a time ‘t’ dependent upon wave amplitude, to collect ‘E’ energy and then decide what to do with it.”?

Or does energy come in packets?

I picture particles like billiard balls surround by a potential barrier. When a photon hits Hydrogen, the photon can either, get over the barrier and be absorbed into the center or there is just a collision with the outer barriers. An EM wave of high energy, but low frequency has a bunch of balls, but individually, they are weak and none can penetrate the absorption barrier. These are photons. These are the packets of energy that bombard a target. The target is not bombarded by some solid piece of energy that the target chooses whether to take a bite out of or not and how big the bite should be. I see no contradictions with the photon, GR and Minkowski space.

QM showed this interaction with matter and quantized energy and QED was just the next step in saying, well, if EM waves are made of photons, then what about the rest of E&M? And QED has been tremendously successful, although, its greatest triumph of the anomalous magnetic dipole moment of the electron is not nearly as good for the muon.

And trying the same strategy to understand gravity in a similar way and make us believe in a graviton has been a failure. While I don’t believe in the graviton, GR reigns supreme here, Einstein was unable to formulate an EM theory with “his” strategy. And QM reigns supreme here.

As of today, IMO, the photon is the explanation for the EM forces and GR is the explanation for the gravitational force.

BTW, one step in disproving the photon would be to give a new model for the photoelectric effect………….just........for starters.

Anonym

???

To the best of my knowledge, they do. I have no reference handy, but all algorithms (iterations, Kalmans, etc.) are based on the Minkowski interval.

Regards, Dany.

cristo

GPS systems involve satellites orbitting a massive body (the earth) and thus must use general relativity somewhere. In fact, GPS uses both special and general relativity. Check out this paper for more info: http://relativity.livingreviews.org/...es/lrr-2003-1/

LorentzR

I was trying to make the distinction between Riemann space and Pseudo Riemann space.

The former is locally modelled on Euclid and the latter, as used in GR, locally modelled on Minkowski.

The metric in a gravitaional field is Schwarzschild's

Anonym

Thank you. Your statement is obviously correct:

“Hence, the principle of the constancy of c finds application as the fundamental concept on which the GPS is based.

Therefore, to implement Eqs. (1 ), the receiver must generally perform a different rotation for each measurement made, into some common inertial frame, so that Eqs. (1 ) apply.

For the GPS it means that synchronization of the entire system of ground-based and orbiting atomic clocks is performed in the local inertial frame, or ECI coordinate system [6].” Etc.

I refer to XVX:” There is no metric for the Universe. And certainly, the perihelion of Mercury was not calculated with the Minkowski metric. And unquestionably, GPS systems do not use the Minkowski metric. The Minkowski metric is GR’s special case in which one has Newton’s Laws and a finite speed limit theory that is commonly known as, SR.”

I am at holydays now and can’t check about Mercury. I am sure that he is wrong about it too. His statements I consider absurd.

Regards, Dany.

cristo

What, particularly, about his statements are absurd? There is no "metric for the universe," since GR is a local theory.

The solution to the precission of the perehilion of Mercury was one of the great successes of GR. This certainly does not use the flat spacetime metric, but instead uses the Schwarzschild metric. You can see this derivation is many GR textbooks if you are not convinced!

Mentz114

There is a metric for the universe. It's called the Friedman-Lemaitre-Robertson-Walker metric. See any book on cosmology.

Anonym

Perhaps I did not understand him properly. Tomorrow I will prepare the answer as needed.

Regards, Dany.

lightarrow

So, which are photon's dimensions? If they existed, would they be independent of its energy? If a photon is a particle, how is its wavefunction related with the existence of that particle in a specific point of space? Is the wavefunction THE particle?

I sincerely cannot understand how you can so easily give real existence to mathematical objects.

Yes, QED has been proved up to a very high degree. Does it mean we should believe in the existence of "energy packets" flying from source to detector? Maybe; but maybe someone could, one day, describe the same results with a different theory.

Certainly, it's not the case to reject a theory that works so well! But I'm not saying this. What I mean is that I can't understand how can low energy photons exist from source A to detector B if you cannot detect them (because you destroy them in doing it).

cristo

Of course, the FRW metric is as close to a model of the visible universe that we have. However, my point was that GR is a local theory, with local curvature. For example, the FRW metric would not describe the metric outside, say, a massive star. In retrospect, my point didn't really answetr the question!

Anyway, this has gotten rather off topic-- I've just noticed that this is a thread in the QP forum!

ZapperZ

Can you show me evidence in history where we actually give in THAT easily? May I remind you how much resistance the Einstein's photoelectric effect model had when it was first introduced? Should I point out to you Millikan's highly skeptical paper on it when he set out to literally falsify it? Where is this "easy" part? I want to know!

So you also have issues with the whole of classical E&M? After all, it IS nothing more than a set of "mathematical objects"? I don't see you complaining about this in the classical physics section whenever classical E&M is discussed. The energy band gap in your semiconductor is also a relic of some mathematical objects. Yet, you freely use it in your electronics.

If such a picture doesn't exist, then show me an alternative explanation to the experimental observations that I have mentioned, which, btw, NO ONE has attempted to tackle. Show me a non-photon formulation of the anti-bunching phenomenon and we'll talk. Yet, all we get are nothing more than objections due to a matter of TASTES! This is not physics and this has never been a valid argument against anything in physics.

Zz.

George Jones

Like cristo, I don't see how GPS calculations can be done solely with the Minkowski metric. Here's a simplified (but still quite accurate) GPS calculation that uses the Schwarzschild metric and some Newtonian approximations.

Anonym

Come on, guys! The original statement was:

“A man ought to read just as inclination leads him; for what he reads as a task will do him little good." I find it strange that I know to read English better than you!!!

Thanks for the refs. Few years ago I was involved in the engineering projects connected with GPS.

Regards, Dany.

George Jones

Yes, and you responded

To me, this seems to say that no other spacetime intervals are needed. Apparently, this is not what what you meant. Phrases like "all are based on" and "all are based soley on" are sometimes used interchangeably.

A bit of a cheap shot. Too easy.