Edmond+Halley



= =

Background

Edmond Halley was born in England in 1656. His father was a wealthy businessman and property owner. His family fell victim to the Great Fire of 1666 but remained wealthy despite the loss in that fire. Edmond Halley’s mother passed away around 1674.(1) In 1684, Edmond Halley married Mary Tooke in England in the midst of his research and career, putting financial strain on his progress in his study. (1) Halley died Jan. 14, 1742, in Greenwich.

Education

Halley was home tutored in his early years. As an adolescent he attended Saint Paul’s School where he excelled in his studies. When he was 17, he attended Queen’s College in Oxford. At such a young age, Halley was already seen as an expert astronomer. He put his educational career on hold to follow the work of John Flamsteed and assist with his observations. His career in research continued for many years, and he finally received academic appointment at Oxford in 1704. (1)

Career and Research

Edmond Halley had an extremely prestigious career. In 1676, Halley catalogued the positions of about 350 Southern Hemisphere stars while working with Flamsteed in St. Helena. (3) Halley also financially supported the research of Isaac and was actively involved in publication of Newton's Principia. (4) In 1686, Halley published the second part of the results from his St. Helena expedition, consisting of a chart of trade winds and monsoons. As a result of this journey and study, Halley also identified solar heating as the cause of atmospheric motions. He also established the relationship between barometric pressure and height above sea level. His research and charting were valuable contributions to the cutting edge field of information visualization during this time period. In 1695, Halley was appointed to deputy controller of the mint at Chester by Newton following the assistance in publication of Philosophiae Naturalis Principia Mathematica. Halley was appointed Savilian professor of geometry at Oxford in 1704, and in 1720 he succeeded John Flamsteed as astronomer royal.(1)

Discoveries

Though Halley ’s Comet is the most popularly known discovery, Halley’s had several others ; some as a result of an expedition to St. Helena financed by King George II (1),including the study of trade winds and monsoons, atmospheric motions caused by solar heating, the relationship between barometric pressure and elevation above sea level. (2) Other discoveries of Halley's include the proper motions of the stars and the acceleration of the moon's mean motion,(4) and while serving as commander of British naval ship, Paramour, studied the variation between the direction a compass needle indicated as north, and True North. (1)

The Comet “A comet (KOM iht) is an icy body that releases gas or dust. Most of the comets that can be seen from Earth travel around the sun in long, oval orbits. A comet consists of a solid nucleus (core) surrounded by a cloudy atmosphere called the coma and one or two tails. Most comets are too small or too faint to be seen without a telescope. Some comets, however, become visible to the unaided eye for several weeks as they pass close to the sun. We can see comets because the gas and dust in their comas and tails reflect sunlight. Also, the gases release energy absorbed from the sun, causing them to glow.” (6) Halley’s comet would be classified as a short-period comet due to the period of orbit consisting of only 76 years for one complete orbit. “Scientists think that short-period comets come from a band of objects called the Kuiper belt, which lies beyond the orbit of Pluto. The gravitational pull of the outer planets can nudge objects out of the Kuiper belt and into the inner solar system, where they become active comets.” (6) There have been sightings recorded of this comet since 240 BC. The comet famously appeared just before the Battle of Hastings in 1066. (3) “Edmond Halley published a work that included his calculations showing that comets observed in 1531, 1607, and 1682 were really one comet and predicting that comet’s return in 1758. The comet was sighted late in 1758, passed perihelion (closest distance to the Sun) in March 1759, and was named in Halley’s honour.” (7) Unfortunately, Halley was not able to see his prediction validated because he had passed away 16 years earlier.

Watch : http://videos.howstuffworks.com/science-channel/29277-100-greatest-discoveries-halleys-comet-video.htm​

REFERENCES 1. http://space.about.com/cs/astronomerbios/a/edmundhalley.htm 2. http://en.wikipedia.org/wiki/Edmond_Halley 3. http://wwp.greenwichpast.com/vip/astronomers/halley.htm 4. "Edmond Halley." The Columbia Encyclopedia, Sixth Edition. 2008. Encyclopedia.com. 24 Jul. 2010 . 5. http://science.discovery.com/videos/100-greatest-discoveries-shorts-halleys-comet.html 6. Yeomans, Donald K. "Comet." World Book Online Reference Center. 2005. World Book, Inc. http://www.worldbookonline.com/wb/Article?id=ar125580 7. http://www.britannica.com/EBchecked/topic/252831/Halleys-Comet 8. http://videos.howstuffworks.com/science-channel/29277-100-greatest-discoveries-halleys-comet-video.htm