How far can light travel on earth or in the atmosphere?
Or, if I want to be more specific, how far can one photon travel until it disintegrates?
I assume gravitational pull and other effects cause it to vanish after a while. Let's say a light beam or laser-beam that has many trillions of photons are shot some distance up from the atmosphere. So, the light rays makes a spotlight on the earth. (I.e. the light is shot in all directions.) Hence, makes a spotlight. If you were a flat earther, you would base your theories on this idea that the spotlight makes the illusion of a spherical earth.
Is there some math equations that knows approximately how far a packet of photons can travel in atmosphere?