Carl Sagan (1934-1996) PDF Print E-mail
Courses - ECGR3090/6090/8090 Spring 2006 : Spacecraft
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Sunday, 14 January 2007 20:34

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When he was young, he graduated from Rahway High School in New Jersey in 1951. He went on to Chicago, where he got his undergrad and graduate degrees in Physics, before getting his doctorate in Astronomy and Astrophysics in 1960. Also in 1971, he became a full professor at Cornell and directed the Laboratory for Planetary Studies there. From 1972 to 1981 he was Associate Director of the Center for Radio Physics and Space Research there as well.
Sagan was central to the discovery of the high surface temperatures of the planet Venus. In the early 1960s, no one knew for certain the basic conditions of Venus' surface and Sagan listed the possibilities in a report (which were later depicted for popularization in a Time-Life book, Planets) — his own view was that the planet was dry and very hot, as opposed to the balmy paradise many other scientists imagined. He investigated radio emissions from Venus and concluded that there was a surface temperature of 500°C (900°F). He also perceived global warming on Earth as a growing, man-made danger and likened it to the natural development of Venus into a hot planet hostile to any life through greenhouse gases. As a visiting scientist to NASA's Jet Propulsion Laboratory, he contributed to the first Mariner missions to Venus, working on the design and management of the project. Mariner 2 confirmed his views on the conditions of Venus in 1962. Sagan was among the first to hypothesize that Saturn's moon Titan and Jupiter's moon Europa may possess oceans (a subsurface ocean, in the case of Europa) or lakes, thus making the hypothesized water ocean on Europa potentially habitable for life. Europa's subsurface ocean was later indirectly confirmed by the spacecraft Galileo. Sagan also helped solve the mystery of the reddish haze seen on Titan, revealing that it is composed of complex organic molecules constantly raining down to the moon's surface. He studied the observed color variations on Mars’ surface, concluding that they were not seasonal or vegetation changes as most believed, but shifts in surface dust caused by windstorms.
However, Sagan is best known for his research on the possibilities of extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by radiation.
 
He conceived the idea of adding an unalterable and universal message on spacecraft destined to leave the solar system that could be understood by any extraterrestrial intelligence that might find it, despite the extremely low probability. Sagan assembled the first physical message that was sent into space: a gold-anodized plaque, attached to the space probe Pioneer 10, which was launched in 1972. The next probe, Pioneer 11, also containing the plaque, was launched the following year. He actually continued to refine his designs and the most elaborate message he helped to develop and assemble was the Voyager Golden Record that was sent out with the Voyager space probes in 1977. In 1982, he formed a petition signed by 70 scientists, 7 of which were Nobel Prize winners in order to get SETI published in the Science Journal. This actually caused a tremendous turnaround in the respectability of this controversial field of searching for alien life and how the public perceived the scientific community. Editor-in-chief of Icarus for 12 years. Co-founded the Planetary Society with over 100,000 members in 140 nations. One of the little-known facts is that Sagan was indeed secretly involved with the Air Force in researching how to explode an atomic bomb on the Moon and the after-effects on Earth. He favored scientific skepticism and was very much against pseudoscience. This meant he was generally skeptical over claims of UFO sightings on the grounds that the chances aliens would travel to Earth were extremely low and that their motivation was emotional rather than scientific; instead, he said the stars would “beckon to humanity” and described the Bussard Ramjet as one way humans might achieve interstellar travel
 
Sagan believed that the Drake equation suggested that a large number of extraterrestrial civilizations would form, but that the lack of evidence of such civilizations (the Fermi paradox) suggests that technological civilizations tend to destroy themselves rather quickly. This stimulated his interest in identifying and publicizing ways that humanity could destroy itself, with the hope of avoiding such a catastrophe and eventually becoming a space-faring species. At the height of the Cold War, Sagan was already involved in public awareness efforts for the effects of nuclear war when a mathematical climate model suggested that a substantial nuclear exchange could upset the delicate balance of life on Earth. So, he eventually co-authored the scientific paper predicting that such a nuclear war would be followed by a nuclear winter. He also co-authored a book where he went into a detailed analysis of a nuclear winter phenomenon. When Soviet leader Mikhail Gorbachev declared a unilateral moratorium on the testing of nuclear weapons starting on August 6, 1985 — which was the 40th anniversary of the atomic bombing of Hiroshima — the Reagan administration actually dismissed the dramatic move as nothing more than propaganda, and refused to follow the same steps. So, in response, American anti-nuclear and peace activists staged a series of protest actions at the Nevada Test Site, beginning on Easter Sunday of 1986 and continuing through 1987. Hundreds of people (including celebrities and scientists) engaged in acts of civil disobedience and were arrested. He had been arrested for participating in an anti-war protest over the Vietnam War, and was also arrested on two separate occasions as he climbed over a chain-link fence at the Test Site. Sagan was an avid user of marijuana, although he never admitted this publicly during his life. He did however write an essay concerning cannabis smoking in the 1971 book Marihuana Reconsidered under the pseudonym "Mr. X".
In this, he commented that marijuana encouraged some of his life’s works and enhanced his experiences. After his death, his biography entitled Carl Sagan: A Life, was published in 1999, the marijuana exposure stirred quite a bit of media attention.
 
It’s said that Sagan possessed the unique gift of being able to convey his ideas in a manner which helped many people to understand the cosmos. He hosted and, with Ann Druyan, co-wrote and co-produced the highly popular 13-part PBS television series Cosmos: A Personal Voyage in 1980. This led it to win an Emmy and Peabody award. It was so popular that the networks broadcast it in 60 countries to about 600 million viewers. He wrote several books to popularize science. From Cosmos and even when he frequently appeared on the Tonight Show with Johnny Carson, and many other celebrities, Sagan became associated with the catch phrase "billions and billions“ even though he never actually said those words in his series.  They would do many affectionate impressions of him using this as their favorite phrase. A humorous unit of measurement, the Sagan, has now been coined to stand for any count of at least 4,000,000,000.
In 1994, Apple Computer began developing the Power Macintosh 7100. They chose the internal code name "Carl Sagan", the in-joke being that the mid-range PowerMac 7100 would make Apple "billions and billions.“ of dollars. Although the project name was strictly internal and was never used in public marketing, when Sagan found out he sued Apple Computer to use a different project name. Other models released conjointly had code names such as "Cold fusion" and "Piltdown Man", and he was very displeased at being associated with what he considered pseudoscience because they tried to relate to the Cold War. Though Sagan lost the suit, Apple engineers complied with his demands anyway, renaming the project "BHA" for (Butt-Head Astronomer). Sagan promptly sued Apple for libel over the new name, claiming that it subjected him to contempt and ridicule, but lost this lawsuit as well. Still, the 7100 saw another name change: it was finally referred to internally as "LAW" for (Lawyers Are Wimps). He wrote frequently about religion and the relationship between religion and science, expressing his skepticism about many conventional conceptualizations of God. For example, he once stated: …
He went on to elaborate, “Others, for example, Baruch Spinoza and Albert Einstein, considered God to be essentially the sum total of the physical laws which describe the universe. I do not know of any compelling evidence for anthropomorphic patriarchs controlling human destiny from some hidden celestial vantage point, but it would be madness to deny the existence of physical laws."
 
After a long and difficult fight with myelodysplasia, a rare bone marrow disease, Sagan died of onset-pneumonia at the age of 62 on December 20, 1996, at the Fred Hutchinson Cancer Research Center in Seattle, Washington. His supporters credit his importance to his popularization of the natural sciences, defending democratic traditions, resisting nationalism, defending humanism, and arguing against geocentric and anthropocentric views, among numerous other causes. As a sign of deep respect and admiration, the landing site of the unmanned Mars Pathfinder spacecraft was renamed the Carl Sagan Memorial Station on July 5, 1997. Asteroid 2709 Sagan is also named in his honor.
REFERENCES
[1] (2007 , January 10) “Carl Sagan”. Wikipedia. [Online] Available: http://en.wikipedia.org/wiki/Carl_Sagan
[2] Lester, M.D. Grinspoon. Marijuana Reconsidered. Quick American Archives, 2nd ed. (1994, April 1) [Online] Available at: http://www.marijuana-uses.com/essays/002.html
[3] W. Poundstone. Carl Sagan: A Life in the Cosmos. Henry Holt & Co. (1999, October 1), pp. 363-364, 374-375.
[4] C. E. Sagan. Broca’s Brain: Reflections on the Romance of Science. Ballantine Books, 1974, Chapter 23.
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