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Carl Sagan

 
Carl Edward Sagan
(born Nov. 9, 1934, Brooklyn, N.Y., N.Y., U.S. — died Dec. 20, 1996, Seattle, Wash.) U.S. astronomer and science writer. He received his Ph.D. from the University of Chicago. At the Smithsonian Astrophysical Observatory (1962 – 68), he focused on planetary astronomy and on SETI efforts to find extraterrestrial life. He gained prominence as a popular science writer and commentator noted for his clear writing and enthusiasm; his Dragons of Eden (1977) won a Pulitzer Prize. He coproduced and narrated the television series Cosmos (1980); its companion book became the best-selling English-language science book of all time. In the 1980s he studied the environmental effects of nuclear war and helped popularize the term nuclear winter.

For more information on Carl Edward Sagan, visit Britannica.com.

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Scientist:

Carl Sagan

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Carl Sagan
Library of Congress (US News & World Report)

[b. New York City, November 9, 1934, d. Seattle, Washington, December 20, 1996]

Sagan promoted planetary astronomy and the search for intelligent life, becoming one of America's best-known scientists through television and popular books. He explained the runaway greenhouse effect on Venus and contributed to the theory that dust from large explosions, such as asteroid impacts, causes mass extinctions by lowering temperatures and stopping photosynthesis over all of Earth.


Biography:

Carl E. Sagan

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The American astronomer and popularizer of science Carl E. Sagan (1934-1996) studied the surfaces and atmospheres of the major planets, conducted experiments on the origins of life on earth, made important contributions to the debate over the environmental consequences of nuclear war, and wrote a number of popular books explaining developments in astronomy, biology, and psychology.

Carl Edward Sagan was born November 9, 1934, in New York City. Pursuing a boyhood fascination with the stars, he studied astronomy at the University of Chicago, receiving his undergraduate degree in 1954 and his doctorate in 1960. After holding teaching and/or research posts at the University of California-Berkeley, Harvard University, the Smithsonian Astrophysical Observatory, and Stanford University, Sagan became director of Cornell University's Laboratory for Planetary Studies and David Duncan Professor of Astronomy and Space Science (1970). In addition to his academic appointments Sagan served as a consultant to the National Aeronautics and Space Administration (NASA) and was closely associated with the unmanned space missions to Venus, Mars, Jupiter, and Saturn. Sagan's work in the popularization of science, which brought him public recognition as author, lecturer, and television personality, won for him the Pulitzer Prize in 1978.

Carl Sagan's main contributions to science were made in the fields of planetary studies and the origin of life. His first major research effort was an investigation of the surface and atmosphere of Venus. In the late 1950s the prevailing scientific view was that the surface of Venus was relatively cool, life of some sort might exist on the planet, and the observed Venusian radio emissions had their origins in the activity of charged particles located in an atmospheric layer. Sagan (1961) overturned this by showing that the emissions could be explained by simply assuming that the Venusian surface was very hot, over 300 degrees Centigrade, and therefore hostile to life. He accounted for the high temperatures by positing the existence of a "greenhouse effect" that resulted from the sun's heat being trapped between the Venusian surface and the planet's carbon dioxide cloud cover. This hypothesis was confirmed by an exploratory space vehicle sent to Venus by the Soviet Union in 1967.

Solar System Research

The physical characteristics of the surface of Mars have long interested astronomers and science fiction writers. Telescopic observation of the planet revealed distinctive bright and dark areas on its surface. This led some to speculate that large regions of Mars were covered with vegetation subject to seasonal changes. So matters stood until the mid-20th century, when radar and other new means of surveillance were used to gather information on the topography, temperature, wind velocities, and atmosphere of Mars. Reviewing this newly collected data, Sagan concluded that the bright regions were lowlands filled with sand and dust blown by the wind and that the dark areas were elevated ridges or highlands. Hence there was no need to assume the existence of extensive Martian plant growth.

Sagan's scientific interest in planetary surfaces and atmospheres led him to investigate the origins of life on earth and to champion the study of exobiology (the biology of extraterrestrial life). In the mid-1950s Harold Urey and Stanley Miller successfully produced key organic compounds in the laboratory by simulating the physical and chemical conditions that prevailed upon earth shortly before the first forms of life appeared. Building upon this research, Sagan irradiated a mixture of methane, ammonia, water, and hydrogen sulfide. In these experiments he was able to produce amino acids and adenosine triphosphate (ATP), complex chemical compounds which are crucial to living cells. Sagan's foray into biochemistry contributed to a better understanding of the nature and origins of terrestrial life and testified to his competence in fields of science beyond astronomy.

Popular Writing

It is not his scientific achievements but his popular books and his television appearances that have made Sagan a well-known public figure. In 1973 he published The Cosmic Connection, a lively introduction to space exploration and the search for extraterrestrial life. Four years later there appeared his Pulitzer Prize winning book on the evolution of human intelligence, The Dragons of Eden. Drawing upon recent work in neuro-physiology and exploring the brain-computer analogy and studies of sleep and dreaming, as well as interpretations of mythology, Sagan created a highly readable, original, and witty account of the development of the human intellect. Another of Sagan's books, Cosmos (1980), deserves notice because it was written in conjunction with his well-received television series of the same name. In this work Sagan offered a summary history of the physical universe, showed how the cosmos came to be understood with the help of modern science, and warned that the earth was in danger of being destroyed by a nuclear holocaust.

In December of 1983 Sagan, with colleagues R. P. Turco, O. B. Toon, T. P. Ackerman, and J. B. Pollack, published "Nuclear Winter: Global Consequences of Multiple Nuclear Explosions," an article which transformed the world-wide public debate over nuclear policy. The authors claimed that in a nuclear war tremendous quantities of soot and dust would be injected into the atmosphere to form a gigantic black cloud covering most of the Northern Hemisphere. This cloud would reduce the incoming sunlight by more than 95 percent for a period of several weeks and affect the climate on earth for a number of years thereafter. During the cold, dark nuclear winter the vegetation which animals and humans need for sustenance would be seriously depleted and great harm would be done to the ecosystem and to human society. In this instance, as so often during the course of his career, Sagan drew upon his extensive knowledge of the forces operating in the atmosphere. However, that knowledge was not used to explain the features of some remote planet but to send a message warning the entire human race of the terrible consequences of nuclear warfare.

Sagan continued to work and proselytize for the furthurance of science until his death in Seattle on December 20, 1996, of pneumonia brought on by a rare bone marrow disease. In July of the following year, upon successful touchdown and deployment on the surface of Mars, the Pathfinder Lander was renamed The Dr. Carl Sagan Memorial Station.

Further Reading

Sagan's career in science and public life to the mid-1970s is covered in Henry S. F. Cooper, Jr., "Profiles (Carl Sagan - I, II)," The New Yorker, June 21 and 28, 1976. Among Sagan's many publications see: Communication with Extraterrestrial Intelligence (1973), The Cosmic Connection (1973), The Dragons of Eden (1977), Broca's Brain (1979), Cosmos (1980), Comet (1985), and Contact (1985).

Additional Sources

Rae Goodell, The Visible Scientist, Little, Brown, 1975.

Carl Sagan, and Richard Turco, A Path Where No Man Thought: Nuclear Winter and the End of the Arms Race, Random House, 1990.[/bibcit.composed

Carl Sagan, Pale Blue Dot: A Vision of the Human Future in Space, Random House, 1994.

Carl Sagan, The Demon-Haunted World: Science as a Candle in the Dark, Random House, 1996.

Carl Sagan, Billions and Billions: Thoughts on Life and Death at the Brink of the Millennium, Random House, 1997.

 
Columbia Encyclopedia:

Carl Edward Sagan

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Sagan, Carl Edward ('gən), 1934-96, American astronomer and popularizer of science, b. New York City. Early in his career he investigated radio emissions from Venus and concluded that the cause was a surface temperature of c.900°F (500°C) and crushing atmospheric pressure. He also studied color variations on Mars' surface, concluding that they were not seasonal changes as most believed but shifts in surface dust caused by windstorms. Both conclusions were substantially confirmed years later by space probes. Sagan is best known, however, for his research on the possibilities of extraterrestrial life (see exobiology), including experimental demonstration of the production of amino acids from basic chemicals by radiation. A professor of astronomy and space sciences at Cornell after 1968, he was involved with numerous NASA planetary space probes and was the creator and host of the 1980 public television science series Cosmos. His publications include The Dragons of Eden (1977; Pulitzer); a novel, Contact (1985); with Richard Turco, A Path Where No Man Thought (1990), on nuclear winter; with Ann Druyan, Shadows of Forgotten Ancestors (1992); Pale Blue Dot (1994); and The Demon-Haunted World (1995).

Bibliography

See biographies by K. Davidson (1999) and W. Poundstone (1999).

Works:

Works by Carl Sagan

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(1934-1996)

1977The Dragons of Eden: Speculation on the Evolution of Human Intelligence. The Cornell University astronomer gains his first bestseller with this popularization of scientific ideas of evolution. It would be followed by the equally popular Broca's Brain: Reflections on the Romance of Science (1979).
1981Cosmos. This is the companion volume for the astronomer's PBS series on the universe. The highest-rated public television program to date, it reached a worldwide audience of 400 million viewers (to be surpassed in 1990 by Ken Burns's The Civil War) and made Sagan a celebrity and his catchphrase, "billions and billions," common parlance. The book remains on the bestseller list for seventy weeks.
1985Contact. The popular astronomer publishes a science fiction thriller about scientist Eleanor Arroway, who receives a message from an alien civilization and is plunged into a media and political frenzy. A film version would appear in 1997.

Quotes By:

Carl Edward Sagan

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Quotes:

"There is today-in a time when old beliefs are withering-a kind of philosophical hunger, a need to know who we are and how we got here. It is an on-going search, often unconscious, for a cosmic perspective for humanity."

"Somewhere, something incredible is waiting to be known."

Actor:

Dr. Carl Sagan

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  • Born: Nov 09, 1934 in New York City, New York
  • Died: Dec 20, 1996 in Seattle, Washington
  • Occupation: Actor
  • Active: '80s-'90s
  • Major Genres: Science & Technology
  • Career Highlights: Contact
  • First Major Screen Credit: Contact (1997)

Biography

Though he was an internationally prominent astrophysicist and astronomer at Cornell University, Carl Sagan is perhaps best known for his 13--part PBS documentary series Cosmos (1980), a science show designed to explain the possible origins of the universe and the nature of space to lay audiences. In 1978, Sagan won a Pulitzer Prize for non-fiction for The Dragons of Eden. In 1985, he penned the speculative, sci-fi novel Contact and in the mid '90s co-produced the big-budget film version that starred Jody Foster. Sagan suffered from bone-marrow disease and in 1996 checked into a Seattle hospital to undergo treatment. On December 20, he died of pneumonia, a complication of the treatment. ~ Sandra Brennan, All Movie Guide
Wikipedia:

Carl Sagan

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Carl Sagan

Born November 9, 1934(1934-11-09)
Brooklyn, New York
Died December 20, 1996 (aged 62)
Seattle, Washington, U.S.
Residence United States[1]
Nationality American
Fields Astronomy and planetary science
Institutions Cornell University
Harvard University
Alma mater University of Chicago
Known for Search for Extra-Terrestrial Intelligence (SETI)
Cosmos: A Personal Voyage
Cosmos
Voyager Golden Record
Pioneer plaque
Contact
Pale Blue Dot
Notable awards Oersted Medal (1990)
NASA Distinguished Public Service Medal (twice)
Pulitzer Prize for General Non-Fiction (1978)
National Academy of Sciences Public Welfare Medal (1994)

Carl Edward Sagan (November 9, 1934 – December 20, 1996) was an American astronomer, astrophysicist, author, and highly successful popularizer of astronomy, astrophysics and other natural sciences. He pioneered exobiology and promoted the Search for Extra-Terrestrial Intelligence (SETI).

He is world-famous for writing popular science books and for co-writing and presenting the award-winning 1980 television series Cosmos: A Personal Voyage, which has been seen by more than 500 million people in over 60 countries.[2] A book to accompany the program was also published. He also wrote the novel Contact, the basis for the 1997 film of the same name. During his lifetime, Sagan published more than 600 scientific papers and popular articles and was author, co-author, or editor of more than 20 books. In his works, he frequently advocated skeptical inquiry, secular humanism, and the scientific method.

Contents

Education and scientific career

Carl Sagan was born in Brooklyn, New York,[3] to a Russian Jewish family. His father, Sam Sagan, was a Russian immigrant garment worker; his mother, Rachel Molly Gruber, a housewife. Carl was named in honor of Rachel's biological mother, Chaiya Clara, "the mother she never knew", in Sagan's words. Sagan graduated from Rahway High School in Rahway, New Jersey in 1951.[4] He attended the University of Chicago, where he participated in the Ryerson Astronomical Society,[5] received an A.B. with general and special honors (1954), an S.B. (1955) and an S.M. (1956) in physics, before earning a Ph.D. degree (1960) in astronomy and astrophysics.[6] During his time as an undergraduate, Sagan spent some time working in the laboratory of the geneticist H. J. Muller. From 1960 to 1962 he was a Miller Fellow at the University of California, Berkeley. From 1962 to 1968, Sagan worked at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts.

Sagan lectured and did research annually at Harvard University until 1968, when he moved to Cornell University in New York. He became a full Professor at Cornell in 1971, and he directed the Laboratory for Planetary Studies there. From 1972 to 1981, Sagan was the Associate Director of the Center for Radio Physics and Space Research at Cornell.

Sagan was a scientist connected with the American space program since its inception. From the 1950s onward, he worked as an advisor to NASA. One of his many duties during his tenure at the space agency included briefing the Apollo astronauts before their flights to the Moon. Sagan contributed to many of the robotic spacecraft missions that explored the solar system during his lifetime, arranging experiments on many of the expeditions. He conceived the idea of adding an unalterable and universal message on spacecraft destined to leave the solar system that could potentially be understood by any extraterrestrial intelligence that might find it. Sagan assembled the first physical message that was sent into space: a gold-anodized plaque, attached to the space probe Pioneer 10, launched in 1972. Pioneer 11, also carrying another copy of the plaque, was launched the following year. He continued to refine his designs throughout his lifetime; 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. Sagan often challenged the decisions to fund the Space Shuttle and Space Station at the expense of further robotic missions.[7]

At Cornell University, Sagan taught a course on critical thinking until he died in 1996 from a rare bone marrow disease.

Scientific achievements

Sagan's contributions were 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 that planet's surface, and Sagan listed the possibilities in a report later depicted for popularization in a Time-Life book, Planets. His own view was that Venus was dry and very hot as opposed to the balmy paradise others had imagined. He had investigated radio emissions from Venus and concluded that there was a surface temperature of 500 °C (900 °F). 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 conclusions on the surface conditions of Venus in 1962.

Sagan was among the first to hypothesize that Saturn's moon Titan might possess oceans of liquid compounds on its surface and that Jupiter's moon Europa might possess subsurface oceans of water. This would make Europa potentially habitable for life.[8] Europa's subsurface ocean of water 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 onto the moon's surface.

He further contributed insights regarding the atmospheres of Venus and Jupiter as well as seasonal changes on Mars. Sagan established that the atmosphere of Venus is extremely hot and dense with pressures increasing steadily all the way down to the surface. He also perceived global warming as a growing, man-made danger and likened it to the natural development of Venus into a hot, life-hostile planet through a kind of runaway greenhouse effect. Sagan and his Cornell colleague Edwin Ernest Salpeter speculated about life in Jupiter's clouds, given the planet's dense atmospheric composition rich in organic molecules. He studied the observed color variations on Mars’ surface and concluded that they were not seasonal or vegetational changes as most believed but shifts in surface dust caused by windstorms.

Sagan is best known, however, for his research on the possibilities of extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by radiation.[9]

He is also the 1994 recipient of the Public Welfare Medal, the highest award of the National Academy of Sciences for "distinguished contributions in the application of science to the public welfare."[10]

Scientific advocacy

Planetary Society members at the organization's founding. Carl Sagan is seated on the right.

Sagan's ability to convey his ideas allowed many people to better understand the cosmos—simultaneously emphasizing the value and worthiness of the human race, and the relative insignificance of the earth in comparison to the universe. He delivered the 1977 series of Royal Institution Christmas Lectures at the Royal Institution in London. He hosted and, with Ann Druyan, co-wrote and co-produced the highly popular thirteen-part PBS television series Cosmos: A Personal Voyage modeled on Jacob Bronowski's The Ascent of Man.

Sagan was a proponent of the search for extraterrestrial life. He urged the scientific community to listen with radio telescopes for signals from intelligent extraterrestrial life-forms. So persuasive was he that by 1982 he was able to get a petition advocating SETI published in the journal Science and signed by 70 scientists including seven Nobel Prize winners. This was a tremendous turnaround in the respectability of this controversial field. Sagan also helped Dr. Frank Drake write the Arecibo message, a radio message beamed into space from the Arecibo radio telescope on November 16, 1974, aimed at informing extraterrestrials about Earth.

Sagan was chief technology officer of the professional planetary research journal Icarus for twelve years. He co-founded the Planetary Society, the largest space-interest group in the world, with over 100,000 members in more than 149 countries, and was a member of the SETI Institute Board of Trustees. Sagan served as Chairman of the Division for Planetary Science of the American Astronomical Society, as President of the Planetology Section of the American Geophysical Union, and as Chairman of the Astronomy Section of the American Association for the Advancement of Science.

At the height of the Cold War, Sagan became 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. He was one of five authors—the "S" of the "TTAPS" report as the research paper came to be known. He eventually co-authored the scientific paper hypothesizing a global nuclear winter following nuclear war.[11] He also co-authored the book A Path Where No Man Thought: Nuclear Winter and the End of the Arms Race, a comprehensive examination of the phenomenon of nuclear winter.

Cosmos covered a wide range of scientific subjects including the origin of life and a perspective of our place in the universe. The series was first broadcast by the Public Broadcasting Service in 1980, winning an Emmy and a Peabody Award. It has been broadcast in more than 60 countries and seen by over 500 million people,[2][12] making it the most widely watched PBS program in history.[13]

Sagan also wrote books to popularize science, such as Cosmos, which reflected and expanded upon some of the themes of A Personal Voyage, and became the best-selling science book ever published in English;[14] The Dragons of Eden: Speculations on the Evolution of Human Intelligence, which won a Pulitzer Prize; and Broca's Brain: Reflections on the Romance of Science. Sagan also wrote the best-selling science fiction novel Contact, but did not live to see the book's 1997 motion picture adaptation, which starred Jodie Foster and won the 1998 Hugo Award.

Pale Blue Dot: Earth is a bright pixel when photographed from "Voyager 1" six billion kilometres out (past Pluto). Sagan encouraged NASA to generate this image.

He wrote a sequel to Cosmos, Pale Blue Dot: A Vision of the Human Future in Space, which was selected as a notable book of 1995 by The New York Times. He appeared on PBS' Charlie Rose program in January 1995.[15] Sagan also wrote an introduction for the bestselling book by Stephen Hawking, A Brief History of Time. Sagan was also known for his popularization of science, his efforts to increase scientific understanding among the general public, and his positions in favor of scientific skepticism and against pseudoscience, such as his debunking of the Betty and Barney Hill abduction. To mark the tenth anniversary of Sagan's passing, David Morrison, a former student of Sagan, recalled "Sagan's immense contributions to planetary research, the public understanding of science, and the skeptical movement" in Skeptical Inquirer.[16]

Sagan hypothesized in January 1991 that enough smoke from the 1991 Kuwaiti oil fires "might get so high as to disrupt agriculture in much of South Asia…" He later conceded in The Demon-Haunted World that this prediction did not turn out to be correct: "it was pitch black at noon and temperatures dropped 4°–6°C over the Persian Gulf, but not much smoke reached stratospheric altitudes and Asia was spared."[17] A 2007 study noted that modern computer models have been applied to the Kuwait oil fires, finding that individual smoke plumes are not able to loft smoke into the stratosphere, but that smoke from fires covering a large area, like some forest fires or the burning of cities that would be expected to follow a nuclear strike, would loft significant amounts of smoke into the stratosphere.[18][19][20][21]

In his later years Sagan advocated the creation of an organized search for near Earth objects that might impact the Earth.[22] When others suggested creating large nuclear bombs that could be used to alter the orbit of a NEO that was predicted to hit the Earth, Sagan proposed the Deflection Dilemma: If we create the ability to deflect an asteroid away from the Earth, then we also create the ability to deflect an asteroid towards the Earth—providing an evil power with a true doomsday bomb.[23][24]

Billions and billions

Sagan with a model of the Viking Lander probes which would land on Mars. Sagan examined possible landing sites for Viking along with Mike Carr and Hal Masursky.

From Cosmos and his frequent appearances on The Tonight Show, Sagan became associated with the catch phrase "billions and billions". As Sagan himself stated, he never actually used the phrase in the Cosmos series.[25] The closest that he ever came was in the book Cosmos, where he talked of "billions upon billions":[26]

A galaxy is composed of gas and dust and stars—billions upon billions of stars.

—Carl Sagan, Cosmos, chapter 1, page 3[27]

However, his frequent use of the word billions, and distinctive delivery emphasizing the "b" (which he did intentionally, in place of more cumbersome alternatives such as "billions with a 'b'", in order to distinguish the word from "millions" in viewers' minds[25]), made him a favorite target of comic performers including Johnny Carson, Gary Kroeger, Mike Myers,[28] Bronson Pinchot, Penn Jillette, Harry Shearer, and others. Frank Zappa satirized the line in the song Be In My Video, noting as well 'atomic light.' Sagan took this all in good humor, and his final book was entitled Billions and Billions which opened with a tongue-in-cheek discussion of this catch phrase, observing that Carson himself was an amateur astronomer and that Carson's comic caricature often included real science.[25]

As a humorous tribute to him, a Sagan has been defined as a humorous unit of measurement equal to at least four billion, since the lower bound of a number conforming to the constraint of billions and billions must be two billion plus two billion.[29][30] Assuming one uses the short scale definition for billion, there are nearly 100 Sagan (400,000,000,000) stars in the Milky Way galaxy.

In 1994, Apple Computer began developing the Power Macintosh 7100. They chose the internal code name "Carl Sagan", the reference being that the mid-range PowerMac 7100 should make Apple "billions and billions."[3] Though the internal project name was never used in public marketing, it did come up in Usenet postings and news of the name grew from there. When Sagan learned of this he sued Apple Computer to force the use of a different project name. Other models released conjointly had code names such as "Cold fusion" and "Piltdown Man", and Sagan was displeased at being associated with what he considered pseudoscience. (He was at the time writing a book discrediting pseudoscience.) Though Sagan lost the lawsuit Apple engineers complied with his demands anyway and renamed 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 he lost this lawsuit as well. Still, the 7100 saw another name change: it was finally referred to internally as "LAW" (Lawyers Are Wimps).[31][32]

Whilst Sagan was outspoken about political issues, the popular perception of his characterization of large cosmic quantities continued to be a sense of wonderment at the vastness of space and time as in his phrase "The total number of stars in the Universe is larger than all the grains of sand on all the beaches of the planet Earth", however this famous saying was widely misunderstood, as he was in fact referring, in his Cosmos series, to the world being at a "critical branch point in history where our actions will propagate down through the centuries" as in the following quote from Cosmos: A personal Voyage: Episode 8: Journeys in Space and Time:

Those worlds in space are as countless as all the grains of sand on all the beaches of the earth. Each of those worlds is as real as ours and every one of them is a succession of incidents, events, occurrences which influence its future. Countless worlds, numberless moments, an immensity of space and time. And our small planet at this moment, here we face a critical branch point in history, what we do with our world, right now, will propagate down through the centuries and powerfully affect the destiny of our descendants, it is well within our power to destroy our civilization and perhaps our species as well.

Social concerns

Sagan believed that the Drake equation, on substitution of reasonable estimates, suggested that a large number of extraterrestrial civilizations would form, but that the lack of evidence of such civilizations highlighted by the Fermi paradox suggests 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 cataclysm and eventually becoming a spacefaring species. Sagan's deep concern regarding the potential destruction of human civilization in a nuclear holocaust was conveyed in a memorable cinematic sequence in the final episode of Cosmos, called "Who Speaks for Earth?" Sagan had already resigned from the Air Force Scientific Advisory Board and voluntarily surrendered his top-security clearance in protest over the Vietnam War.[33] Following his marriage to his third wife (novelist Ann Druyan) in June 1981, Sagan became more politically active—particularly in opposing escalation of the nuclear arms race under President Ronald Reagan.

In March 1983, Reagan announced the Strategic Defense Initiative—a multi-billion dollar project to develop a comprehensive defense against attack by nuclear missiles, which was quickly dubbed the "Star Wars" program. Sagan spoke out against the project, arguing that it was technically impossible to develop a system with the level of perfection required, and far more expensive to build than for an enemy to defeat through decoys and other means—and that its construction would seriously destabilize the nuclear balance between the United States and the Soviet Union, making further progress toward nuclear disarmament impossible.

When Soviet leader Mikhail Gorbachev declared a unilateral moratorium on the testing of nuclear weapons, which would begin on August 6, 1985—the 40th anniversary of the atomic bombing of Hiroshima—the Reagan administration dismissed the dramatic move as nothing more than propaganda, and refused to follow suit. In response, American anti-nuclear and peace activists staged a series of protest actions at the Nevada Test Site, beginning on Easter Sunday in 1986 and continuing through 1987. Hundreds of people were arrested, including Sagan, who was arrested on two separate occasions as he climbed over a chain-link fence at the test site.

Personal life and beliefs

Sagan married three times: in 1957, to biologist Lynn Margulis, mother of Dorion Sagan and Jeremy Sagan; in 1968, to artist Linda Salzman, mother of Nick Sagan; and in 1981, to author Ann Druyan, mother of Alexandra Rachel (Sasha) Sagan and Samuel Democritus Sagan. His marriage to Druyan continued until his death in 1996.

Isaac Asimov described Sagan as one of only two people he ever met whose intellect surpassed his own. The other, he claimed, was the computer scientist and artificial intelligence expert Marvin Minsky.[34]

Sagan wrote frequently about religion and the relationship between religion and science, expressing his skepticism about the conventional conceptualization of God as a sapient being. For example:

Some people think God is an outsized, light-skinned male with a long white beard, sitting on a throne somewhere up there in the sky, busily tallying the fall of every sparrow. 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.[35]

Sagan, however, denied that he was an atheist: "An atheist has to know a lot more than I know."[36] In reply to a question in 1996 about his religious beliefs, Sagan answered, "I'm agnostic."[37] Sagan maintained that the idea of a creator of the universe was difficult to prove or disprove and that the only conceivable scientific discovery that could challenge it would be an infinitely old universe.[38]

In 2006, Ann Druyan edited Sagan's 1985 Glasgow Gifford Lectures in Natural Theology into a book, The Varieties of Scientific Experience: A Personal View of the Search for God, in which he elaborates on his views of divinity in the natural world.

Sagan is also widely regarded as a freethinker or skeptic; one of his most famous quotations, in Cosmos, was, "Extraordinary claims require extraordinary evidence."[39] This was based on a nearly identical statement by fellow founder of the Committee for the Scientific Investigation of Claims of the Paranormal founder Marcello Truzzi, "Extraordinary claims require extraordinary proof."[40] This idea originated with Pierre-Simon Laplace (1749-1827), a French mathematician and astronomer who said, "The weight of evidence for an extraordinary claim must be proportioned to its strangeness."[41] Sagan nominated three areas within paranormal research that he considered to have sufficient experimental support, albeit dubious, to warrant serious study. These related to thoughts barely affecting random number generators (psychokinesis); projection of images from one person to another (telepathy); and young children sometimes reporting verifiable details of previous lives (reincarnation research). He was at pains to point out that he was not convinced by the validity of these contentions, merely that they might be true.[42]

Late in his life, Sagan's books elaborated on his skeptical, naturalistic view of the world. In The Demon-Haunted World: Science as a Candle in the Dark, he presented tools for testing arguments and detecting fallacious or fraudulent ones, essentially advocating wide use of critical thinking and the scientific method. The compilation Billions and Billions: Thoughts on Life and Death at the Brink of the Millennium, published in 1997 after Sagan's death, contains essays written by Sagan, such as his views on abortion, and his widow Ann Druyan's account of his death as a skeptic, agnostic, and freethinker.

Sagan warned against humans' tendency to anthropocentrism. He was the faculty adviser for the Cornell Students for the Ethical Treatment of Animals. In the Cosmos chapter "Blues For a Red Planet", Sagan wrote, "If there is life on Mars, I believe we should do nothing with Mars. Mars then belongs to the Martians, even if the Martians are only microbes."[43]

Sagan was a user of marijuana. Under the pseudonym "Mr. X", he contributed an essay about smoking cannabis to the 1971 book Marihuana Reconsidered.[44][45] The essay explained that marijuana use had helped to inspire some of Sagan's works and enhance sensual and intellectual experiences. After Sagan's death, his friend Lester Grinspoon disclosed this information to Sagan's biographer, Keay Davidson. The publishing of the biography, Carl Sagan: A Life, in 1999 brought media to this aspect of Sagan's life.[46][47][48]

In 1966, Sagan was asked to contribute an interview about the possibility of extraterrestrials to a proposed introduction to the film 2001: A Space Odyssey. Sagan reportedly asked for control and a percentage of the film's box office receipts in return; these terms were rejected.[49]

Sagan and UFOs

Sagan had some interest in UFO reports from at least 1964 when he had several conversations on the subject with Jacques Vallee.[50] Though quite skeptical of any extraordinary answer to the UFO question, Sagan thought scientists should study the phenomenon, at least because there was widespread public interest in UFO reports.

Stuart Appelle notes that Sagan "wrote frequently on what he perceived as the logical and empirical fallacies regarding UFOs and the abduction experience. Sagan rejected an extraterrestrial explanation for the phenomenon but felt there were both empirical and pedagogical benefits for examining UFO reports and that the subject was, therefore, a legitimate topic of study."[51]

In 1966, Sagan was a member of the Ad Hoc Committee to Review Project Blue Book, the U.S. Air Force's UFO investigation project. The committee concluded Blue Book had been lacking as a scientific study, and recommended a university-based project to give the UFO phenomenon closer scientific scrutiny. The result was the Condon Committee (1966–1968), led by physicist Edward Condon, and in their final report they formally concluded that UFOs, regardless of what any of them actually were, did not behave in a manner consistent with a threat to national security.

Ron Westrum writes that "The high point of Sagan's treatment of the UFO question was the AAAS's symposium in 1969. A wide range of educated opinions on the subject were offered by participants, including not only proponents such as James McDonald and J. Allen Hynek but also skeptics like astronomers William Hartmann and Donald Menzel. The roster of speakers was balanced, and it is to Sagan's credit that this event was presented in spite of pressure from Edward Condon".[50] With physicist Thornton Page, Sagan edited the lectures and discussions given at the symposium; these were published in 1972 as UFOs: A Scientific Debate. Some of Sagan's many books examine UFOs (as did one episode of Cosmos) and he claimed a religious undercurrent to the phenomenon.

Sagan again revealed his views on interstellar travel in his 1980 Cosmos series. In one of his last written works, Sagan argued that the chances of extraterrestrial spacecraft visiting Earth are vanishingly small. However, Sagan did think it plausible that Cold War concerns contributed to governments misleading their citizens about UFOs, and that "some UFO reports and analyses, and perhaps voluminous files, have been made inaccessible to the public which pays the bills ... It's time for the files to be declassified and made generally available." He cautioned against jumping to conclusions about suppressed UFO data and stressed that there was no strong evidence that aliens were visiting the Earth either in the past or present.[52]

Death and legacy

Stone dedicated to Carl Sagan in the Celebrity Path of the Brooklyn Botanic Garden

After a long and difficult fight with myelodysplasia, which included three bone marrow transplants, Sagan died of pneumonia at the age of 62 at the Fred Hutchinson Cancer Research Center in Seattle, Washington on December 20, 1996. After landing, 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. He was buried at Lakeview Cemetery in Ithaca, New York.

The 1997 movie Contact, based on Sagan's novel of the same name and finished after his death, ends with the dedication "For Carl".

On November 9, 2001, on what would have been Sagan's 67th birthday, the NASA Ames Research Center dedicated the site for the Carl Sagan Center for the Study of Life in the Cosmos. "Carl was an incredible visionary, and now his legacy can be preserved and advanced by a 21st century research and education laboratory committed to enhancing our understanding of life in the universe and furthering the cause of space exploration for all time", said NASA Administrator Daniel Goldin. Ann Druyan was at the Center as it opened its doors on October 22, 2006.

Sagan's son, Nick Sagan, wrote several episodes in the Star Trek franchise. In an episode of Star Trek: Enterprise entitled "Terra Prime", a quick shot is shown of the relic rover Sojourner, part of the Mars Pathfinder mission, placed by a historical marker at Carl Sagan Memorial Station on the Martian surface. The marker displays a quote from Sagan: "Whatever the reason you're on Mars, I'm glad you're there, and I wish I was with you." Sagan's student Steve Squyres led the team that landed the Spirit Rover and Opportunity Rover successfully on Mars in 2004.

Sagan has at least three awards named in his honor:

In 2006, the Carl Sagan Medal was awarded to astrobiologist and author David Grinspoon, the son of Sagan's friend Lester Grinspoon.

On December 20, 2006, the tenth anniversary of Sagan's death, a blogger, Joel Schlosberg, organized a Carl Sagan "blog-a-thon" to commemorate Sagan's death, and the idea was supported by Nick Sagan.[54] Many members of the blogging community participated.

In 2008, Benn Jordan, also known as The Flashbulb, released the album "Pale Blue Dot: A Tribute to Carl Sagan".

In 2009, clips from Carl Sagan's Cosmos were used as the basis for A Glorious Dawn, the first video produced for the Symphony of Science, an educational music video production by composer John Boswell. Musician Jack White later released this song as a vinyl single under his record label Third Man Records.[55] Additional clips were used in the followup video, We Are All Connected, which featured Sagan alongside other noted scientists Richard Feynman, Neil Degrasse Tyson, and Bill Nye.

Also in 2009, the 75th anniversary of Carl Sagan's birth, the First "Carl Sagan Day" has been celebrated on November 7.[56]

Awards and honors

NASA Distinguished Public Service Medal

Publications

References

  1. ^ Sagan, Carl (1994). Pale Blue Dot: A Vision of the Human Future in Space (1st ed.). New York: Random House. p. 68. ISBN 0-679-43841-6. 
  2. ^ a b "StarChild: Dr. Carl Sagan". NASA. http://starchild.gsfc.nasa.gov/docs/StarChild/whos_who_level2/sagan.html. Retrieved 2009-10-08. 
  3. ^ a b Poundstone, William (1999). Carl Sagan: A Life in the Cosmos. New York: Henry Holt & Company. pp. 363–364, 374–375. ISBN 0-805-05766-8. 
  4. ^ Davidson, Keay (1999). Carl Sagan: A Life. John Wiley & Sons. pp. 33–41. ISBN 0-471-25286-7. 
  5. ^ http://astro.uchicago.edu/RAS/
  6. ^ Graduate students receive first Sagan teaching awards
  7. ^ Charlie Rose interview, January 5, 1994
  8. ^ Much of Sagan's research in the field of planetary science is outlined by William Poundstone. Poundstone's biography of Sagan includes an 8-page list of Sagan's scientific articles published from 1957 to 1998. Detailed information about Sagan's scientific work comes from the primary research articles. Example: Sagan, C., Thompson, W. R., and Khare, B. N. Titan: A Laboratory for Prebiological Organic Chemistry, Accounts of Chemical Research, volume 25, page 286 (1992). There is commentary on this research article about Titan at The Encyclopedia of Astrobiology, Astronomy, and Spaceflight.
  9. ^ The Columbia Encyclopedia. "Sagan, Carl Edward". Sixth Edition. Columbia University Press. http://www.bartelby.com/65/sa/Sagan-Ca.html. Retrieved 2007-05-02. 
  10. ^ The Planetary Society. "Carl Sagan". The Planetary Society. http://www.planetary.org/about/founders/carl_sagan.html. Retrieved 2007-05-14. 
  11. ^ Turco RP, Toon OB, Ackerman TP, Pollack JB, Sagan C. Climate and smoke: an appraisal of nuclear winter, Science, volume 247, pages 166-176 (1990). PubMed abstract JSTOR link to full text article. Carl Sagan discussed his involvement in the political nuclear winter debates and his erroneous global cooling prediction for the Gulf War fires in his book, The Demon-Haunted World.
  12. ^ "Carl Sagan". EMuseum@Minnesota State University. http://www.mnsu.edu/emuseum/information/biography/pqrst/sagan_carl.html. Retrieved 2009-10-08. 
  13. ^ "CosmoLearning Astronomy". CosmoLearning. http://www.cosmolearning.com/documentaries/cosmos/. Retrieved 2009-10-08. 
  14. ^ "Meet Dr. Carl Sagan". The Science Channel. http://science.discovery.com/convergence/cosmos/bio/bio.html?clik=fsmain_feat3. Retrieved 2007-05-02. 
  15. ^ Carl Sagan, Astronomer: Author of Pale Blue Dot: A Vision of the Human Future in Space. Interview with Charlie Rose. Charlie Rose. PBS New York. 1995-01-05. (Interview [.SWF]). Retrieved on 2007-04-25. starts at 00:39:29
  16. ^ Morrison, David (2007). Man for the Cosmos: Carl Sagan's Life and Legacy as Scientist, Teacher, and Skeptic. Skeptical Inquirer January/February, 31(1), pp. 29-38.
  17. ^ Sagan, Carl (1996). The demon-haunted world: science as a candle in the dark. New York: Random House. p. 257. ISBN 0-394-53512-X. 
  18. ^ In-situ observations of mid-latitude forest fire plumes deep in the stratosphere
  19. ^ EO Newsroom: New Images - Smoke Soars to Stratospheric Heights
  20. ^ Observations of Boreal Forest Fire Smoke in the Stratosphere
  21. ^ Fromm (2006). "Smoke in the Stratosphere: What Wildfires have Taught Us About Nuclear Winter". Eos Trans. AGU 87 (52 Fall Meet. Suppl.): Abstract U14A–04. http://www.agu.org/cgi-bin/SFgate/SFgate?&listenv=table&multiple=1&range=1&directget=1&application=fm06&database=%2Fdata%2Fepubs%2Fwais%2Findexes%2Ffm06%2Ffm06&maxhits=200&=%22U14A-04%22. 
  22. ^ Head, Tom (2006). Conversations With Carl Sagan. University Press of Mississippi. pp. 86–87. ISBN 1-578-06736-7. 
  23. ^ "David Morrison - Taking a Hit: Asteroid Impacts & Evolution". Silicon Valley Astronomy Lectures. 2007-10-03.
  24. ^ Sagan, Carl; Ostro (1994), "Long-Range Consequences of Interplanetary Collisions", Issues in Science and Technology Vol X (Number 4) 
  25. ^ a b c Sagan, Carl; p. 3-4 (1998). Billions and Billions. New York: Ballantine Books. ISBN 0-345-37918-7. 
  26. ^ Fred R. Shapiro and Joseph Epstein (2006). "Carl Sagan". The Yale Book of Quotations. Yale University Press. pp. 660. ISBN 0-300-10798-6. 
  27. ^ Carl Sagan (1980). Cosmos. Ballantine Books. ISBN 0-345-33135-4. 
  28. ^ Myers portrayed Sagan in "SNL: Carl Sagan's Global Warming Christmas Special [VIDEO]"<http://www.alternet.org/blogs/video/71374/>
  29. ^ Sagan at dictionary.reference.com (definition from the Jargon File)
  30. ^ William Safire, ON LANGUAGE; Footprints on the Infobahn, New York Times, April 17, 1994
  31. ^ "This Week in Apple History: November 14-20". The Mac Observer. http://www.macobserver.com/columns/thisweek/2004/20041120.shtml. 
  32. ^ Carl Sagan, Plaintiff, v. Apple Computer, Inc., Defendant CV 94-2180 LGB (BRx) United States District Court for the Central District of California 874 F. Supp. 1072; 1994 U.S. Dist. Lexis 20154 June 27, 1994, Decided June 27, 1994, Filed
  33. ^ http://findarticles.com/p/articles/mi_m1374/is_6_60/ai_78889720/
  34. ^ Asimov, Isaac (1980). In Joy Still Felt: The Autobiography of Isaac Asimov, 1954-1978. Doubleday/Avon. pp. 217, 302. ISBN 0-380-53025-2. 
  35. ^ Sagan, Carl (1986-02-12). "Chapter 23". Broca's Brain: Reflections on the Romance of Science. Ballantine Books. p. 330. ISBN 0345336895. 
  36. ^ Achenbach, Joel (2006-04-23). "Worlds Away". Washington Post: p. W15. http://www.washingtonpost.com/wp-dyn/content/article/2006/04/18/AR2006041801870.html. 
  37. ^ Head, Tom. "Conversations with Carl". Skeptic 13 (1): 32–38. Excerpted in Head, Tom, ed. (2006). University of Mississippi Press. ISBN 1-57806-736-7.. 
  38. ^ Sagan, Carl (1996). The Demon Haunted World: Science as a Candle in the Dark. New York: Ballantine Books. p. 278. ISBN 0-345-40946-9. 
  39. ^ "Encyclopaedia Galactica". Carl Sagan (writer/host). Cosmos. PBS. 1980-12-14. No. 12. 01:24 minutes in.
  40. ^ Truzzi, Marcello (1998). "On Some Unfair Practices towards Claims of the Paranormal". Oxymoron: Annual Thematic Anthology of the Arts and Sciences, Vol.2: The Fringe. Oxymoron Media. http://www.skepticalinvestigations.org/anomalistics/practices.htm. Retrieved 2007-05-02. 
  41. ^ A sense of place in the heartland, The Milwaukee Journal Sentinel Online
  42. ^ Sagan (1996), p. 302
  43. ^ Sagan, Carl (1985-10-12). Cosmos. Ballantine Books. p. 108. ISBN 0345331354. 
  44. ^ Grinspoon, Lester (1994). Marihuana Reconsidered (2nd ed.). Oakland, CA: Quick American Archives. ISBN 0-932-55113-0. 
  45. ^ Sagan, Carl. "Mr. X". Marijuana-Uses.com. http://www.marijuana-uses.com/essays/002.html. Retrieved 2009-08-07. 
  46. ^ Whitehouse, David (1999-10-15). "Carl Sagan: A Life in the Cosmos". BBC News. http://news.bbc.co.uk/1/hi/sci/tech/475954.stm. Retrieved 2007-05-02. 
  47. ^ Davidson, Keay (1999-08-22). "US: Billions and Billions of '60s Flashbacks". San Francisco Examiner. http://www.druglibrary.org/think/~jnr/sagan.htm. Retrieved 2007-05-02. 
  48. ^ Larsen, Dana (1999-11-01). "Carl Sagan: Toking Astronomer". Cannabis Culture Magazine. http://cannabisculture.com/articles/63.html. Retrieved 2007-05-02. 
  49. ^ Anthony Barnes (2005-10-23). "2001: The Secrets of Kubrick's Classic". The Independent. http://arts.independent.co.uk/film/news/article321643.ece. Retrieved 2009-08-07. 
  50. ^ a b Westrum, Ron; Jacobs, David Michael (ed.) (2000). "Limited Access: Six Natural Scientists and the UFO Phenomenon". UFOs and abductions: Challenging the Borders of Knowledge. Lawrence, Kansas: University Press of Kansas. pp. 30–55. ISBN 0-700-61032-4. 
  51. ^ Appelle, Stuart; Jacobs, David Michael (ed.) (2000). "Ufology and Academia: The UFO Phenomenon as a Scholarly Discipline". UFOs and abductions: Challenging the Borders of Knowledge. Lawrence, Kansas: University Press of Kansas. pp. 7–30. ISBN 0-700-61032-4. 
  52. ^ Sagan, 1996: 81-96, 99-104
  53. ^ "Sagan Award for Public Understanding of Science". The Council of Scientific Society Presidents. http://cssp.us/index.php?option=content&task=view&id=17&Itemid=47. Retrieved 2007-05-02. 
  54. ^ Joel's humanistic blog: Announcing the Carl Sagan memorial blog-a-thon
  55. ^ "Jack White: Carl Sagan's Biggest Fan". The Washington Post. http://voices.washingtonpost.com/reliable-source/2009/11/jack_white_carl_sagans_biggest.html. Retrieved 2009-11-11. 
  56. ^ http://www.carlsaganday.com/
  57. ^ New Jersey to Bon Jovi: You Give Us a Good Name Yahoo News, February 2, 2009

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