The increase in the frequency of starlight because of the Doppler shift. If a yellow star is moving toward you, it's light will appear slightly bluish. In outer space, blue shifted galaxies are rare. Blue shift can also be created by shrinking the space between two points via gravity or space warps.
Red shift is more common than blue shift because most objects in our expaning universe are moving away from us.
Prices shown in USD.
Type your email address below to get our free Urban Word of the Day every morning!
Emails are sent from email@example.com. We'll never spam you.