Charles Dillon Perrine facts for kids
Quick facts for kids
Charles Dillon Perrine
|
|
|---|---|
 |
|
| Born | July 28, 1867 Steubenville, Ohio, U.S.
|
| Died | June 21, 1951 (aged 83) |
| Alma mater | Santa Clara College (honorary doctorate) (1905) |
| Known for | First attempts at light deflection test of relativity (1912 solar eclipse, Brazil; 1914 solar eclipse, Russia). Discovery of sixth and seventh Moons of Jupiter: Himalia, Elara |
| Spouse(s) | Bell (Smith) Perrine (m. 1905) |
| Awards | Lalande Prize (1897) Astronomical Society of Mexico Gold Medal (1905) Donohoe Comet Medals (x5) from the Astronomical Society of the Pacific Panama–Pacific International Exposition Gold Medal (1915) |
| Scientific career | |
| Fields | Astronomy, astrophysics, astrophotography |
| Institutions | Lick Observatory, Argentine National Observatory |
| Influences | William Wallace Campbell |
Charles Dillon Perrine (July 28, 1867 – June 21, 1951) was an American astronomer. He worked at the Lick Observatory in California from 1893 to 1909. Later, he became the Director of the Argentine National Observatory in Cordoba, Argentina (1909-1936).
Perrine's work in Argentina included early attempts to test Albert Einstein's famous Theory of Relativity. He tried to observe how starlight bends near the Sun during solar eclipses. These attempts happened in 1912 in Brazil and 1914 in Russia. Unfortunately, bad weather stopped these tests from working.
In 1897, he won the Lalande Prize from the Paris Academy of Sciences. This award is given for important astronomical observations. He also served as president of the Astronomical Society of the Pacific in 1902. In 1905, he received an honorary Doctor of Sciences degree.
Contents
Biography
Early Life
Charles Perrine was born in Steubenville, Ohio. His father, Peter, was a minister. Charles moved to Alameda, California around 1886. He worked as a bookkeeper in San Francisco.
From a young age, Charles was very interested in photography and astronomy. He could not afford to go to college. However, he really wanted to work in astronomy. In 1889, he sent a report and photos of a total solar eclipse to the Lick Observatory. The Director, E. S. Holden, was impressed. He hired Charles as a Secretary in 1893. Holden agreed that Charles could spend his free time studying astronomy. This helped him prepare for future observatory duties.
Career Highlights
As Charles gained more experience and made discoveries, he was promoted. He became an Assistant Astronomer in 1902 and a full Astronomer in 1905.
Between 1895 and 1902, Perrine discovered many comets. He found eight new comets and four comets that return regularly. One of these was 18D/Perrine-Mrkos. Later, an asteroid called 6779 Perrine was named after him. A crater on the Moon, called Perrine, also carries his name.
In 1904 and 1905, he made a very exciting discovery. He found the sixth and seventh moons of Jupiter. Today, these moons are known as Himalia (discovered December 3, 1904) and Elara (discovered February 21, 1905). He found them using a special camera attached to a telescope. Before this, only five of Jupiter's moons were known. Galileo Galilei found the first four in 1610. The fifth, Amalthea, was found in 1892.
Perrine also joined four solar eclipse expeditions for the Lick Observatory. He traveled to Georgia (USA) in 1900, Sumatra in 1901, Spain in 1905, and Flint Island in 1908. He was in charge of the expedition to Sumatra.
In 1909, Charles Perrine left the Lick Observatory. He became the Director of the Argentine National Observatory in Cordoba, Argentina. He held this important job until he retired in 1936.
Testing Einstein's Theory
Perrine played an early role in testing Albert Einstein's Theory of Relativity. Einstein's theory, proposed in 1905, suggested that gravity could bend light. In 1911, Einstein hoped astronomers would try to prove this idea.
Dr. Erwin Finlay-Freundlich, a German astronomer, asked Perrine for help. Perrine agreed to try and test the light-bending idea during a total solar eclipse. He planned to add this test to his expedition to Cristina, Brazil, for the eclipse on October 10, 1912.
The Lick Observatory Director, William Wallace Campbell, also encouraged Perrine. He loaned Perrine special camera lenses. The Argentine National Observatory built telescopes and prepared equipment. Sadly, heavy rain on the day of the eclipse made it impossible to see anything. Perrine said, "We suffered a total eclipse instead of observing one."
Even though they didn't get results, the expedition was useful. They gained experience and had new equipment for the next eclipse. Three observatories planned expeditions for the 1914 eclipse in Russia. Perrine's Argentine National Observatory was one of them.
Perrine took the first photograph during the solar eclipse of August 21, 1914, to try and measure how starlight bends. But thin clouds blocked the view just enough. This made it impossible to get accurate measurements of the stars.
It's interesting to note that if these early attempts in 1912 or 1914 had worked, they would have shown Einstein's prediction was wrong at that time. From 1911 to 1914, Einstein had predicted a light bending of 0.87 arcseconds. Later, in 1915, with his General Theory of Relativity, he calculated it to be 1.75 arcseconds. The later prediction was proven correct by other expeditions.
Perrine was a pioneer in the study of astrophysics in Argentina. He pushed for the building of a large telescope at Bosque Alegre. This telescope was finished in 1942, after he retired in 1936. It was the largest telescope in South America until 1981.
After retiring, Perrine lived in Cordoba city and then in Villa General Mitre. He passed away there and is buried in the Cementerio del Salvador in Córdoba.
Comets discovered or co-discovered
- C/1895 W1 (Perrine)
- C/1896 C1 (Perrine-Lamp)
- C/1896 V1 (Perrine)
- 18D/Perrine-Mrkos
- C/1897 U1 (Perrine)
- C/1898 L2 (Perrine)
- C/1898 R1 (Perrine-Chofardet)
See also
In Spanish: Charles Dillon Perrine para niños
