Scientific photography and astronomy: Technology applied to understanding the universe

Abstract

In 1925, Edwin Hubble took the first step towards increasing the size of the known universe by several orders of magnitude by using the precarious photographic methods available at the time: glass plates and photosensitive emulsions. Analysing periodic variations in the brightness of certain stars (Cepheids) by using photographs, Hubble was able to show that the distance between Andromeda and the Earth was much greater than previously thought. Thus, Andromeda, previously thought to be a nebula, had to be a galaxy different from our own. Suddenly, the estimated size of the universe went from a few hundred thousand light years to a few billion light years. Since then, the synergy between photographic technology and astronomy has continued to grow.