I Does the Photon Play a Crucial Role in Quantum Mechanics?

[Vanadium 50]

that massless particles don't experience time

Does an electron? After all, an electron that is 1000 years old acts identically to one that was just created.

This seems to be a) philosophical and not something subject to test via measurement and b) a set of properties unnecessary for understanding how matter behaves. Does an inclined plane experience time? How do you know, and what difference does it make?

 

[PeterDonis]

Isn't spacetime an emergent property of the universe?

What does this even mean?

I maintain that massless particles don't experience time. They are incapable of having internal clocks.

If by this you mean that the concepts of "experienced time" and "internal clocks" are not even well-defined for massless particles, that is correct. I covered this way back in post #3. However, that does not justify the further claims you made.

I don't know why you would argue this point.

I am not. I am simply pointing out, as above, that the correct point that I am not arguing does not justify the further claims you made that I did argue.

 

[PeterDonis]

Thread closed for moderation.

 

[PeterDonis]

After moderator review, the thread will remain closed.

 

[bhobba]

I know the tread is closed, but ages ago, I found an excellent paper that can be understood after a first course in QM (Susskind would be enough with persistence) that explains why a photon must exist. It was historically first worked out by Dirac. The issue is spontaneous emission. Einstein explained it in one of his famous papers that high school students these days learn about. But Dirac used the principles of QM to explain those rules. It was the first 'taste' of Quantum Field Theory, the foundation of the modern standard model. Without further ado:

https://www.physics.usu.edu/torre/QFT/Lectures/QFT_text.pdf

Thanks
Bill