2007-03-01 05:04:09 · 2 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
We know that certain types of stars should be emitting specific wavelengths of light. However what we observe when we look at them is that the stars all emit light that is slightly lower in wavelength then they should be... it's "shifted" towards the red end of the spectrum. THis is something called the "red shift". The reason is that the stars are moving away from us at very high rates of speed. It's similar to how a car or train horn will sound as it travels away from you. The sound starts off high and then as the car moves away the frequencey gets lower. The same thing is happening here. When we measure exactly how much the wavelegnth has shifted it tells us how quickly the star is moving away from us.
2007-03-01 05:14:07 · answer #1 · answered by Louis G 6 · 2⤊ 0⤋
By the doppler effect.
Wiki "red shift".
2007-03-01 13:07:32 · answer #2 · answered by Jerry P 6 · 0⤊ 0⤋