Thread: Photons and expanding waves of light.

I have seen references in different publications to light being propagated as an expanding sphere in Space (or SpaceTime ).

I at first imagined this as being caused by a single photon being released but it seems to me that this will not cause an expanding sphere of light but rather a pencil like "beam"

What is required to cause this "expanding sphere " of light? Is it millions of photons being released practically simultaneously in all directions?

Secondly:I am trying to understand the wave nature of this "expanding sphere".

Is the wave attached to the individual particle (or particles) or is it a property of the "front " of the "expanding sphere" .

I mean is it at all analogous to the wave that we make when we disturb the water with a stone -or is that a misleading analogy ?

Can I imagine millions of photons being released more or less simultaneously forming a "wave front" at the surface of an "expanding sphere of light" ?

If all the millions of photons that were released simultaneously were identical would that produce a perfectly spherical "expanding sphere of light" whereas any difference in the photons could be expected to produce an imperfectly spherical "expanding sphere of light"?