Edwin Hubble and the Discovery of Galaxies
Lecture no. 31 from the course: The Joy of Science
Taught by Professor Robert M. Hazen | 30 min | Categories: The Great Courses Plus Online Science Course
In 1924, Edwin Hubble discovered that galaxies are immense collections of gravitationally bound stars. Astronomers have since catalogued thousands of galaxies. Hubble also found a close relationship between a galaxy's distance and its "red shift," a change in light wavelengths caused by rapid movement away from us. As telescopes have improved, the estimated number of galaxies has grown to tens of billions.