I got an interesting theoretical question about light particle emission rate (if that even makes sense). The setting:
In a perfect vacuum, we have a perfect laser pointer (the beam is perfectly focused, so the "dot" is the size of aperture at any distance) with circular aperture (say 1 mm if that is relevant) and infinite plane parallel to laser pointer at some finite distance. Laser pointer is being rotated at 1 rad/s (axis of rotation coincides with aperture).
The further the plane is the faster the dot moves across the plane. "Normally" we would observe a line painted by the laser pointer. If light is emitted as distinct particles, there must be certain emission rate. Then if the plane is far enough, linear speed of "dot" will be so high, that distinct particles would hit the plane at distances larger than Planck's distance and the line would become dotted/dashed instead of solid.
The questions. Is it appropriate to say that light is emitted in distinct particles or is light emission continuous no matter what? What is light particle emission rate (wrt intensity/power and possibly other properties)? What should the linear speed of the "dot" (distance from pointer axis of rotation to plane) be that we could observe dotted line?