Help with physics Hubbles constant PLEASE.Watch
I know it says the galaxy is red shifted by 15% of their normal wavelengths - but what does it actually mean by this? I don't understand.
e.g. a source emitting 550nm (yellow/green) would be shifted to (1.15 x 550) = 632.5nm (orange)
you want to feed it into the Doppler equation
(don't think you do much with z at A level but you'll see it quite often in the literature where it's used as a shorthand... high z galaxy means high red shift galaxy example)