Observatory

An observatory is a location used for observing terrestrial or celestial events. Astronomy, climatology/meteorology, geology, oceanography and volcanology are examples of disciplines for which observatories have been constructed. Historically, observatories were as simple as containing an astronomical sextant (for measuring the distance between stars) or Stonehenge (which has some alignments on astronomical phenomena).

Astronomical observatories

Astronomical observatories are mainly divided into four categories: space based, airborne, ground based and underground based.

Ground-based observatories

Ground-based observatories, located on the surface of Earth, are used to make observations in the radio and visible light portions of the electromagnetic spectrum. Most optical telescopes are housed within a dome or similar structure, to protect the delicate instruments from the elements. Telescope domes have a slit or other opening in the roof that can be opened during observing, and closed when the telescope is not in use. In most cases, the entire upper portion of the telescope dome can be rotated to allow the instrument to observe different sections of the night sky. Radio telescopes usually do not have domes.

Los Angeles

Los Angeles (ⁱ/lɒs ˈændʒəlᵻs/ loss AN-jə-ləs or loss AN-jə-liss) (Spanish for "The Angels"), officially the City of Los Angeles and often known by its initials L.A., is the second-largest city in the United States after New York City, the most populous city in the state of California, and the county seat of Los Angeles County.

Situated in Southern California, Los Angeles is known for its mediterranean climate, ethnic diversity, sprawling metropolis, and as a major center of the American entertainment industry. Los Angeles lies in a large coastal basin surrounded on three sides by mountains reaching up to and over 10,000 feet (3,000 m).

Historically home to the Chumash and Tongva, Los Angeles was claimed by Juan Rodríguez Cabrillo for Spain in 1542 along with the rest of what would become Alta California. The city was officially founded on September 4, 1781, by Spanish governor Felipe de Neve. It became a part of Mexico in 1821 following the Mexican War of Independence. In 1848, at the end of the Mexican–American War, Los Angeles and the rest of California were purchased as part of the Treaty of Guadalupe Hidalgo, thereby becoming part of the United States. Los Angeles was incorporated as a municipality on April 4, 1850, five months before California achieved statehood. The city experienced rapid growth with the discovery of oil.

Hollywood Sign

The Hollywood Sign (formerly the Hollywoodland Sign) is a landmark and American cultural icon located in Los Angeles, California. It is situated on Mount Lee, in the Hollywood Hills area of the Santa Monica Mountains. The sign overlooks Hollywood, Los Angeles.

"HOLLYWOOD" is spelled out in 45-foot-tall (14 m) white capital letters and is 350 feet (110 m) long. It was originally created in 1923 as an advertisement for a local real estate development, but it garnered increasing recognition after the sign was left up. The sign was a frequent target of pranks and vandalism, but it has since undergone restoration, including the installation of a security system to deter vandalism. The sign is protected and promoted by The Trust For Public Land, a nonprofit organization, while its site and the surrounding land are part of Griffith Park.

From the ground, the contours of the hills give the sign a "wavy" appearance, as reflected in the Hollywood Video logo, for example. When observed at a comparable altitude, the letters appear nearly level.

Griffith Observatory

Griffith Observatory is a facility in Los Angeles, California sitting on the south-facing slope of Mount Hollywood in Los Angeles' Griffith Park. It commands a view of the Los Angeles Basin, including Downtown Los Angeles to the southeast, Hollywood to the south, and the Pacific Ocean to the southwest. The observatory is a popular tourist attraction with an excellent view of the Hollywood sign, and an extensive array of space and science-related displays. Since the observatory opened in 1935, admission has been free, in accordance with Griffith's will. However, some planetary shows inside have a small added charge.

History

3,015 acres (12.20 km²) of land surrounding the observatory was donated to the City of Los Angeles by Colonel Griffith J. Griffith on December 16, 1896. In his will Griffith donated funds to build an observatory, exhibit hall, and planetarium on the donated land. Griffith's objective was to make astronomy accessible by the public, as opposed to the prevailing idea that observatories should be located on remote mountaintops and restricted to scientists.