A flashtube or laser emits a flash of light. I don't think for this
question it matters whether it is a single photon or a bunch of photons. I
don't think it matters whether the duration of the flash was a microsecond
or a femtosecond, but it was much shorter than one second.
Some of the light is headed across "empty space" to a detector located 10
light seconds from the source. When approximately 5 seconds have elapsed,
describe the space between the source and detector... what's there...
anything describable?
Michael D. Edmiston, Ph.D. Phone/voice-mail: 419-358-3270
Professor of Chemistry & Physics FAX: 419-358-3323
Chairman, Science Department E-Mail edmiston@bluffton.edu
Bluffton College
280 West College Avenue
Bluffton, OH 45817