Ken Colburn from Data Doctors explains how to navigate Google Maps and measure distances whether on your computer or using your phone.

This relation between mass, curve, and brightness, has allowed scientists to calculate the distance to a lot of clusters of galaxies, fixing more points in the giant jigsaw puzzle.

How do Cepheid variables indicate distance? The length of these stars' pulsations is always related to their intrinsic brightness. Astronomers can use this knowledge to calculate distance.