Blog #3- Mt. Wilson, Morgan Grimes

September 25, 2019

Mt. Wilson Observatory

Built in 1904, Mt. Wilson Observatory is home to many historic telescopes, as well as countless astronomical discoveries. The first telescope completed at the observatory was the snow telescope completed in 1905. The 60–inch telescope in 1908 and the 100-inch telescope, or the Hooker Telescope followed this telescope, in 1917. Due to its unique location in the San Gabriel Mountains, Mt. Wilson has been a prime location for many to come and study astronomy. The history of the telescopes and those who made discoveries on them is a fascinating journey into the past, and includes some of the fundamentals of astronomy that we understand today.

Of the many telescopes at the observatory, the 60-inch and the 100-inch telescopes are some of the most fascinating. The 60-inch was constructed in 1908 and was the largest in the world at the time. It was built with a glass mirror instead of metal and a precision mount which made it by far the most advanced at the time. It had farther sight and was designed for higher amounts of light. This telescope was used for spectroscopic analysis, the study of the interaction between matter and electromagnetic radiation, parallax measurements, measuring the difference between apparent and actual position of objects in space, as well as nebula and photometric photography.

The 100-inch telescope, widely known as the Hooker Telescope, was constructed in 1917. This telescope was also the largest in the world at the time. It continued to be the largest in the world for nearly three decades, when it was beat out by the 200-inch Hale Telescope in 1949. Edwin Hubble used it in the early 1900s to make historical discoveries that changed the way we thought about space, and planted foundations in astronomy that we still use today. In 1923 Edwin Hubble proved that the Andromeda Nebula was outside of our own Milky Way Galaxy. This was incredible as before this time the swirls seen in space were thought to be simply another part to our own vast galaxy. It was during this time that our galaxy was thought to be the only one. Proving that Andromeda was outside our galaxy disproved that our galaxy was the entire universe. There was suddenly a whole new frontier to explore, far beyond what we had ever imagined. In 1929 Hubble, alongside Milton Humason discover that the Universe is expanding, and are even able to measure the expansion rate, as well as the size of the known Universe. This was a huge discovery as before this time the universe was thought to be static. In 1917 Einstein proposed his theory of relativity on a static universe, but with gravity being the only force, he concluded the universe would collapse. This discovery by Hubble gave Einstein the solution to his problem, an expanding rather than constant universe.

These discoveries were just two among countless that have been made atop Mt. Wilson. This historic place has been used for over a century and continues in use today. Observers from around the globe have come to see for themselves what incredible discoveries lie at their fingertips at Mt. Wilson.