Why do light particles behave like waves?

[Mentz114]

The whole idea that a photon can be deflected by a force, such as the sun, is of course a contradiction to the constant speed of light rule. For any force, hence acceleration, implies a velocity that is greater than the speed of light. Therefore, in a sense, the one particle, two slit phenomenon is a constradiction of this law.

Utter rubbish. OP don't pay attention to this.

 

[muppet]

ZapperZ... I don't think I've ever heard the word description sound so pejorative
No-one can seriously dispute that we have an excellent operational understanding of the physical laws governing the behaviour of what we understand to be light. But do you think it's fair to say that we have quite a limited understanding of the physical meaning of a wavefunction? My perspective from both reading and my lectures is that we have a fantastic mathematical model, without much idea of what underlying physical phenomena lead to the results observed in experiment to conform to our formulation, in much the same way that Newton's formula of gravity was limited to describing the results of his observations well, wheras Einstein's offered a rough mechanism by which those phenomena occurred (the bending of spacetime). In that respect, I'd find myself in some disagreement with you: we have an incredible description of how the systems behave (in the language of maths); but quite poor knowledge of the nature of the objects that comprise the system!

 

[ZapperZ]

ZapperZ... I don't think I've ever heard the word description sound so pejorative
No-one can seriously dispute that we have an excellent operational understanding of the physical laws governing the behaviour of what we understand to be light. But do you think it's fair to say that we have quite a limited understanding of the physical meaning of a wavefunction? My perspective from both reading and my lectures is that we have a fantastic mathematical model, without much idea of what underlying physical phenomena lead to the results observed in experiment to conform to our formulation, in much the same way that Newton's formula of gravity was limited to describing the results of his observations well, wheras Einstein's offered a rough mechanism by which those phenomena occurred (the bending of spacetime). In that respect, I'd find myself in some disagreement with you: we have an incredible description of how the systems behave (in the language of maths); but quite poor knowledge of the nature of the objects that comprise the system!

But you are forgetting that Einstein presents no "explanation" on why spacetime HAS to be warped in the presence of a massive body. If you look closely, SR and GR are also "description", not "explanation". In fact, find everything that you think are "explanation", and I'll show you immediately that they are "description". This is because when you explain a higher level phenomenon, that explanation then becomes merely a description when a lower level explanation comes along. This process continues ad nauseum as far as we have seen so far.

For example, you discover that an object suddenly has a resistivity drop to zero below a certain temperature. You then later discover that the explanation for it is the ability for the charge carrier to move in the material with zero resistance. That's the explanation. But really, if you start asking what causes it to move with zero resistance, then the explanation becomes nothing more than a description because you are expecting a lower level explanation for it. You discover that you can in fact construct a coherent wavefunction called the order parameter, and by using several phenomenological parameters, you actually managed to "explain" why the charge carrier could actually propagate without any resistance. But then you start asking the origin of such wavefunction, and now your last explanation starts to become a description because you think you can find a lower-level explanation for it, and you do. You find that the formation of cooper pairs can produce a composite boson made up of electron pairs, and this can actually condensed into a coherent state that propagates without any resistance. So you have found an explanation on the origin of the wavefunction. Are you done? No! Someone can easily ask what is the mechanism that produce such cooper pairs, and why can't you come up with an explanation to include ALL of the conduction electrons in the material, not just 1 electron pair? Etc... etc... Do you see what I'm getting at?

The QM wavefunction (actually, it is the Hamiltonian, since in many real systems, you do NOT solve the wavefunction because it is unsolvable) is the "explanation" for many phenomena. But the wavefunction itself is nothing more than a description of the system, the same way that Maxwell equations are a description on EM phenomena. Each time you think you've come up with an "explanation", look at it carefully. What you got was a description.

Zz.

 

[muppet]

But you are forgetting that Einstein presents no "explanation" on why spacetime HAS to be warped in the presence of a massive body. If you look closely, SR and GR are also "description", not "explanation". In fact, find everything that you think are "explanation", and I'll show you immediately that they are "description". This is because when you explain a higher level phenomenon, that explanation then becomes merely a description when a lower level explanation comes along. This process continues ad nauseum as far as we have seen so far.

For example, you discover that an object suddenly has a resistivity drop to zero below a certain temperature. You then later discover that the explanation for it is the ability for the charge carrier to move in the material with zero resistance. That's the explanation. But really, if you start asking what causes it to move with zero resistance, then the explanation becomes nothing more than a description because you are expecting a lower level explanation for it. You discover that you can in fact construct a coherent wavefunction called the order parameter, and by using several phenomenological parameters, you actually managed to "explain" why the charge carrier could actually propagate without any resistance. But then you start asking the origin of such wavefunction, and now your last explanation starts to become a description because you think you can find a lower-level explanation for it, and you do. You find that the formation of cooper pairs can produce a composite boson made up of electron pairs, and this can actually condensed into a coherent state that propagates without any resistance. So you have found an explanation on the origin of the wavefunction. Are you done? No! Someone can easily ask what is the mechanism that produce such cooper pairs, and why can't you come up with an explanation to include ALL of the conduction electrons in the material, not just 1 electron pair? Etc... etc... Do you see what I'm getting at?

The QM wavefunction (actually, it is the Hamiltonian, since in many real systems, you do NOT solve the wavefunction because it is unsolvable) is the "explanation" for many phenomena. But the wavefunction itself is nothing more than a description of the system, the same way that Maxwell equations are a description on EM phenomena. Each time you think you've come up with an "explanation", look at it carefully. What you got was a description.

Zz.

Ok, I'm now out of my depth on the theory But I understand your point.
I think the OP, in these terms, really amounts to saying that we have no lower level explanation that the wavefunction describes.
Do you think such a level (e.g. the "pilot wave" proposal of De Broglie and later Bohm) exists?

 

[ZapperZ]

Ok, I'm now out of my depth on the theory But I understand your point.
I think the OP, in these terms, really amounts to saying that we have no lower level explanation that the wavefunction describes.
Do you think such a level (e.g. the "pilot wave" proposal of De Broglie and later Bohm) exists?

I don't know, and at this point, no one does. As an experimentalist, as long as none of these have any empirical and practical differences, I think it is a waste of time to argue which one exists and which doesn't.

Zz.