B How does the propagation of light work? How much time does it take?

[lordoftheselands]

I'm quite aware that according to Einstein light is a particle and a wave at the same time.

However, I try to imagine how exactly would light expand. A photon must likely have a certain timing for expansion. I mean, after a photon is originated it immedialy multiplies itself into many other photons, all of them moving in all directions so that a single photon can be seen from all directions.

Ok, now the question is: how much time does it take for a photon to multiply from a single one to many photons? And how many photons are originated?

 

[DaveC426913]

A photon must likely have a certain timing for expansion. I mean, after a photon is originated it immedialy multiplies itself into many other photons, all of them moving in all directions so that a single photon can be seen from all directions.

No. Photons do not expand or multiply.

The light source emits many photons over time.
It is possible to dim some light sources so much that they effectively emit only a single photon at a time. This is useful for 2-slit experiments.

 

[berkeman]

I'm quite aware that according to Einstein light is a particle and a wave at the same time.

However, I try to imagine how exactly would light expand. A photon must likely have a certain timing for expansion. I mean, after a photon is originated it immedialy multiplies itself into many other photons, all of them moving in all directions so that a single photon can be seen from all directions.

Ok, now the question is: how much time does it take for a photon to multiply from a single one to many photons? And how many photons are originated?

Welcome to PF.

Can you post links to the reading you have been doing to understand EM and photons, etc.?

Also, are you familiar with how PMTs work, and how they can detect single photon events?

 

[PeroK]

I'm quite aware that according to Einstein light is a particle and a wave at the same time.

You mean that photons are the quanta of the electromagnetic field?

A photon must likely have a certain timing for expansion.

It doesn't.

I mean, after a photon is originated it immedialy multiplies itself into many other photons

It doesn't.

, all of them moving in all directions so that a single photon can be seen from all directions.

It doesn't work like this.

Ok, now the question is: how much time does it take for a photon to multiply from a single one to many photons?

If a single photon is generated, then typically it remains a single photon.

 

[vanhees71]

One should abandon the idea of photons in physics learning (and teaching!) as long as the students do not have a clear understanding of the classical picture. Photons are among the most complicated concepts of modern physics and can only be properly understood in terms of relativistic quantum field theory. Einstein's heuristic concept of photons as localized massless point particles of 1905 is seriously flawed, and Einstein himself never has been satisfied with any conception of em. radiation during his lifetime. Famously he also was very skeptical against modern quantum mechanics, including relativistic QFT, which in 1955 however was much less understood than it is today, and even today it's not a complete mathematically well-defined theory.

 

[tech99]

It is possible to dim some light sources so much that they effectively emit only a single photon at a time. This is useful for 2-slit experiments.

Even a dim light source might emit two or more photons at the same time.

 

[Steve4Physics]

Also, are you familiar with how PMTs work ...

For clarification, I believe @berkeman is referring to the photomultiplier tube, not pre-menstrual tension.