[lenadorap (OP)]

If photons travel at the speed of light, a clock in a photon shall be stand-still. If it is stand-still photon shall not change or undistructable. How this could be explained?

[Soul Surfer]

The fact that time does not pass for a photon does not mean that a photon cannot be created or destroyed.  from its "point of view"  it is just created and then destroyed whether it lasted  a picosecond or most of the age of the universe during its life from our point of view.

[JP]

Also, the usual idea that time doesn't pass for a photon is wrong.  Time doesn't actually stand still for a photon according to our theories.  The idea that time slows down for objects that move fast only applies to those with mass, which can never move at the speed of light.  We don't know how to describe the "point of view" of light itself. 

[Soul Surfer]

Agreed JP,  Strictly the point of view of a photon or any fundamental particle does not make much sense but photons only change when they interact nonlinearly and are either absorbed or changed in energy so there are no real points of reference.

[imatfaal]

we can posit, theorise, and experiment on single electrons - so I think the FoR of some elementary particles makes a lot of sense; the massless ones I agree not, and the tricksy ones that are never found in isolation perhaps it would be better not to, and I guess now that the neutrinos are all superluminal (I know it is still unconfirmed) we have to be careful about them; and the ew bosons and the mu and the tau last less time than its worth bothering about ... perhaps you are right after all :-)

[simplified]

Photon has kinematic time of motion.

[yor_on]

You mean in its annihilation?

You won't see a photon anywhere, except in its release of 'energy' dying, as I understands it. But as we also seem to assume that waves can 'reflect' elastically, changing 'momentum' (direction) but not 'kinetic energy'?

It most definitely should be a duality.

[simplified]

You mean in its annihilation?

You won't see a photon anywhere, except in its release of 'energy' dying, as I understands it. But as we also seem to assume that waves can 'reflect' elastically, changing 'momentum' (direction) but not 'kinetic energy'?

It most definitely should be a duality.

No. I can know way and speed. And at all maybe photon is small tornado in gravitational field of universe. []

[yor_on]

I don't agree there Simplified, you can deduce a path, but not 'know' it. It's enough comparing it to a balls path to see the difference there. And all deducing involves statistical approaches, as far as I know. You can only measure a photon once, in its annihilation. That you can define them as being 'identical' of property and then assume that by measuring a large amount coming from a same source, at different positions, do not give you a photons path, as various 'slit experiment' also can show you, depending on interpretation.

[simplified]

I don't agree there Simplified, you can deduce a path, but not 'know' it. It's enough comparing it to a balls path to see the difference there. And all deducing involves statistical approaches, as far as I know. You can only measure a photon once, in its annihilation. That you can define them as being 'identical' of property and then assume that by measuring a large amount coming from a same source, at different positions, do not give you a photons path, as various 'slit experiment' also can show you, depending on interpretation.

I think you confuse different waves.
Photon has quantum wave.Such wave is  wave in a narrow corridor of travel.

[yor_on]

"According to the wave model of light, the speed of the electrons should be related to the intensity of the light. But that's not what happens. In reality the speed of the electrons depends only on the frequency of light, and the light intensity determines the number of electrons that fly off." (photoelectric effect.)

As for if a photon is a 'quantum wave'? Don't know, but I doubt it. A photon is not a wave, it is a quanta of energy.

[simplified]

Then quanta of energy of electron is photon. Does it travel at 'c'?

[yor_on]

yes, if you are talking about a 'photon', not a electron.

[simplified]

yes, if you are talking about a 'photon', not a electron.

Can electron have quanta of energy? What is quanta of energy?

[JP]

Quantum states are often defined in terms of quantized values: physical quantities such as energy, momentum, position, angular momentum, and so on that take on only discrete values.  You can't generalize to all particles about what values get quantized, but for each type of particle and situation there are rules. 

Photons are, by definition, the smallest quanta of energy you can get from an electromagnetic field of a given frequency.  If I shine a green laser at you, the green photons that make it up are the tiniest possible piece of energy you can pick out of that beam.  Because they are defined as energy quanta, they do not have a simple description in terms of how they spread out over space, so you can't properly draw a photon wave traveling through space.

[simplified]

Quantum states are often defined in terms of quantized values: physical quantities such as energy, momentum, position, angular momentum, and so on that take on only discrete values.  You can't generalize to all particles about what values get quantized, but for each type of particle and situation there are rules. 

Photons are, by definition, the smallest quanta of energy you can get from an electromagnetic field of a given frequency.  If I shine a green laser at you, the green photons that make it up are the tiniest possible piece of energy you can pick out of that beam.  Because they are defined as energy quanta, they do not have a simple description in terms of how they spread out over space, so you can't properly draw a photon wave traveling through space.

Can you properly draw a corridor of travel of photon in space?

[JP]

No.  Photons don't follow classical paths through space.

[simplified]

No.  Photons don't follow classical paths through space.

Then I don't understand why shadows of objects can be predicted? 

[yor_on]

There are different approaches Simplified. Some do want to see it as one path, but that isn't how the experiments I know of describe it. But all agree in that the source (laser) and the sink (detector) are connected, and they also, like Feynman's interference or otherwise, leave only one path existing as the defined outcome. And it's those 'final' paths that then defines the shadow you cast.

[JP]

No.  Photons don't follow classical paths through space.

Then I don't understand why shadows of objects can be predicted? 

You can predict where billions of photons will go, or where a photon interacting with matter (a photon in an optical fiber, for example) will go.  But you can't predict the path taken by a true photon (meaning one that is described as the smallest packet of energy of an electromagnetic field).