Spark image

The Doppler Effect, Hubble and the Expansion of the Universe

The diagrams show a greater and greater red shift as the star (or galaxy) moves away from the observer at greater and greater speeds. In the last diagram one of the absorption lines had been moved into the infrared region of the spectrum. By measuring the amount of red shift for a certain line we can calculate the speed of recession of the star (or galaxy).
© Keith Gibbs 2007