Is the photon that reaches your eye from a distant galaxy the very same one that started its journey across intergalactic space?

Yes, barring any pit stops along the way. By this I mean that some photons may interact with interstellar matter and the atoms in the Earth's atmosphere which is not fully transparent, but the majority of the photons take the direct route to your eye by about 10 to 1!


Copyright 1997 Dr. Sten Odenwald
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