- #1
- 11,308
- 8,737
The speed of light in a vacuum is the universal constant c. The speed of light in a medium is something less than c; let's call it s.
Has the positive difference (c-s) been observed as light travels through ordinary matter in space such as gaseous nebula or plasma nebula? If no, is it because the mean inter-particle distance is large compared to the wavelength of the light?
Has the positive difference (c-s) been observed as light travels through clouds of dark matter? If no is it because dark matter does not interact with light regardless of density?
Has the positive difference (c-s) been observed as light travels through ordinary matter in space such as gaseous nebula or plasma nebula? If no, is it because the mean inter-particle distance is large compared to the wavelength of the light?
Has the positive difference (c-s) been observed as light travels through clouds of dark matter? If no is it because dark matter does not interact with light regardless of density?