When people hear the name “Edwin Hubble,” they typically think of the Hubble Space Telescope. However, the Hubble Space Telescope was built after Edwin Hubble’s death as a way to honor him. So, who was Edwin Hubble, and what did he do that was so important? Hubble was an astronomer whose observations were centered around the viewing of faint and fuzzy spots of light in the night sky that were broadly labeled nebulae. The discoveries he would make about these “nebulae” would change cosmology forever.
Nebulae are clouds of gas and particles in space. In the early 20th Century, the word “nebula” was used to describe many objects in the night sky that were too faint or diffuse to be observed. Hubble was specifically interested in the Andromeda Nebula, and he was able to observe specific stars in the “nebula,” including a Cepheid variable star. Cepheid variable stars are unique in the fact that their brightness changes, cycling from bright, to dim, to bright again. This allows these stars to be used in measuring distances to astronomical objects. When Edwin Hubble measured the distance to the Andromeda, he found that its calculated distance was far outside the estimated bounds of the Milky Way galaxy. This meant that the Andromeda nebula was actually a galaxy.
The perception of the universe at the time was based inside the bounds of the Milky Way galaxy, and while other galaxies were theorized to exist, there was no observable evidence that they did until Hubble made his discovery. Hubble went on to observe 24 more “nebulae” and continued to discover new galaxy after new galaxy. He devised a system of classification of galaxies based on their shape: elliptical or spiral. This was called the Hubble Classification Scheme, and it is still used to this day.
Hubble also found that the further away a galaxy is, the faster it moves away from us. This is known as Hubble’s Law. Hubble observed the light of different galaxies through spectroscopy, the process of breaking light up into lines of colors. When observing the spectra of different galaxies, he determined that the universe is continuously expanding outwards.
Hubble’s findings of an expanding universe were key in the discovery of the Big Bang theory and the origins of the universe. Hubble changed our perception and understanding of the universe forever. Before, there was only one galaxy, but now there are hundreds-of-billions. Edwin Hubble opened our minds to the possible reality of an ever-expanding universe instead of a stationary one. If you ask me, that is worth getting a telescope named after you.
You’ve been listening to Western Slope Skies, produced by the Black Canyon Astronomical Society and KVNF Community Radio. This feature was written and recorded by Stephen Bruner, an astronomy student of Dr. Catherine Whiting at Colorado Mesa University.
