the unit in detamining the distance in space is astronomical unit ,i"m in doubt in this standard because astronomers they assume that the speed of ligth is constant,ist possible the dead stars,dwarf nebula dusty and may be others matters which are not well known there densities ,properties and other physical properties are equally penetrated by ligth with equl speed?
2006-08-06 12:45:25 · 3 answers · asked by solo4lamus-mon 1 in Science & Mathematics ➔ Astronomy & Space
Don't think I've totally deciphered your nearly unintelligible question, but the speed of light is constant ONLY in an absolute vacuum. Light can be absorbed, reflected, refracted, etc., by all kinds of different things in the universe. The astronomical unit is the distance between Earth and the sun and is used as short hand for specifying distances less than one light year. At such relatively short ranges the speed of light isn't significantly affected.
2006-08-06 12:54:50 · answer #1 · answered by Chug-a-Lug 7 · 4⤊ 0⤋
Astronomers DO NOT count on light travelling at constant velocities, however there is simply NO OTHER more reliable way to measure Space-Time at present. All matter is "penetrated" at light-speed, WHETHER THE LIGHT MAKES IT THROUGH THAT MATERIAL OR NOT IS ANOTHER MATTER. This can be told by the spectrum that the light has shifted to many times, also by the spectrum spread that the light has been contamined by while in the dust cloud.
So until there's simply a better way to "classify" space-time, light-speed will be the best way.
2006-08-06 13:44:45 · answer #2 · answered by AdamKadmon 7 · 0⤊ 0⤋
Light speed varies according to the medium it travels. It is constant in vacuum and in any medium. The light year is based on the speed of light in Vacuum
2006-08-06 15:45:50 · answer #3 · answered by Dr M 5 · 0⤊ 0⤋