HISTORY OF SCIENCE AND TECHNOLOGY

MOUNT WILSON OBSERVATORY

Mount Wilson Observatory is located at 1740 meters in altitude in the San Gabriel Mountains, near Pasadena, California. It was built by George Ellery Hale in 1904 and is presently owed by the Carnegie Institution of Washington, D.C. In this high position, allowing a view of clear skies, it attracted many now-famous astronomers who visited Mount Wilson Observatory to use the telescopes. Edwin Hubble used the Hooker telescope, the most powerful in the world in 1929, to collect data that allowed him to show that the universe is expanding. This eventually led to the “Big Bang” theory.

The observatory houses five reflecting telescopes, two dating from 1908 and a third, Hooker Telescope built in 1917 but it has been out of action since 1985. There is also a telescope erected on a tower that belongs to the University of California. This telescope is working on exploring the Sun’s magnetic activity. More recently another telescope, known as CHARA, has been added to the collection. It is operated by George Washington University. CHARA is really six telescopes mounted so that their signals can be combined to make it appear as one, very powerful, telescope.

The observatory studies the structure and dimensions of the universe, as well as the chemical and physical nature of the objects in the night sky as they evolve. The CHARA telescope measures surface details of stars and tracks the movement of double stars. It can even look at planets orbiting stars, other than the Sun, and watch planets as they form!

• History of Science and Technology Index