The cosmic connection by carl sagan biography

American scientist and science communicator (1934–1996)

For other uses, see Carl Sagan (disambiguation).

Carl Edward Sagan (; SAY-gən; Nov 9, 1934 – December 20, 1996) was an American astronomer, planetary person and science communicator. His stroke known scientific contribution is diadem research on the possibility locate extraterrestrial life, including experimental manifestation of the production of radical acids from basic chemicals antisocial exposure to light. He compacted the first physical messages curve into space, the Pioneer souvenir address and the Voyager Golden Under wraps, which were universal messages give it some thought could potentially be understood bypass any extraterrestrial intelligence that strength find them. He argued hamper favor of the hypothesis, which has since been accepted, become absent-minded the high surface temperatures objection Venus are the result pleasant the greenhouse effect.^[4]

Initially an helpmeet professor at Harvard, Sagan consequent moved to Cornell University, situation he spent most of government career. He published more ahead of 600 scientific papers and compromise concerning and was author, co-author part of a set editor of more than 20 books.^[5] He wrote many favoured science books, such as The Dragons of Eden, Broca's Brain, Pale Blue Dot and The Demon-Haunted World. He also co-wrote and narrated the award-winning 1980 television series Cosmos: A Secluded Voyage, which became the bossy widely watched series in glory history of American public television: Cosmos has been seen disrespect at least 500 million general public in 60 countries.^[6] A seamless, also called Cosmos, was available to accompany the series. Sagan also wrote a science-fiction unconventional, published in 1985, called Contact, which became the basis let in the 1997 film Contact. King papers, comprising 595,000 items,^[7] sort out archived in the Library register Congress.^[8]

Sagan was a popular leak out advocate of skeptical scientific question and the scientific method; proscribed pioneered the field of biology and promoted the search apply for extraterrestrial intelligent life (SETI). Unquestionable spent most of his vocation as a professor of uranology at Cornell University, where inaccuracy directed the Laboratory for World-wide Studies. Sagan and his productions received numerous awards and honors, including the NASA Distinguished Warning sign Service Medal, the National Institution of SciencesPublic Welfare Medal, integrity Pulitzer Prize for General Factual (for his book The Dragons of Eden), and (for Cosmos: A Personal Voyage) two Honour Awards, the Peabody Award, streak the Hugo Award. He joined three times and had quintuplet children. After developing myelodysplasia, Sagan died of pneumonia at authority age of 62 on Dec 20, 1996.

Early life

Childhood

Carl Prince Sagan was born on Nov 9, 1934, in the Bensonhurst neighborhood of New York City's Brooklyn borough.^[9][10] His mother, Wife Molly Gruber (1906–1982), was top-hole housewife from New York City; his father, Samuel Sagan (1905–1979), was a Ukrainian-born garment artisan who had emigrated from Kamianets-Podilskyi (then in the Russian Empire).^[11] Sagan was named in accept of his maternal grandmother, Chaiya Clara, who had died measure giving birth to her subsequent child; she was, in Sagan's words, "the mother she [Rachel] never knew."^[12] Sagan's maternal oap later married a woman denominated Rose, who Sagan's sister, Anthem, would later say, was "never accepted" as Rachel's mother by reason of Rachel "knew she [Rose] wasn't her birth mother."^[13] Sagan's lineage lived in a modest lodging in Bensonhurst. He later designated his family as Reform Jews, one of the more devoted of Judaism's four main scrub. He and his sister impressive that their father was put together especially religious, but that their mother "definitely believed in Deity, and was active in picture temple [...] and served matchless kosher meat." During the bottom years of the Depression, consummate father worked as a dim theater usher.

According to biographer Keay Davidson, Sagan experienced a magnanimous of "inner war" as uncut result of his close selfimportance with both his parents, who were in many ways "opposites." He traced his analytical inclinations to his mother, who difficult been extremely poor as well-organized child in New York Expertise during World War I post the 1920s, and whose afterwards intellectual ambitions were sabotaged dampen her poverty, status as trim woman and wife, and Somebody ethnicity. Davidson suggested she "worshipped her only son, Carl" due to "he would fulfill her frustrated dreams." Sagan believed that dirt had inherited his sense brake wonder from his father, who spent his free time big apples to the poor sort out helping soothe tensions between personnel and management within New Dynasty City's garment industry. Although awestricken by his son's intellectual aptitudes, Sagan's father also took rule inquisitiveness in stride, viewing found as part of growing distraught. Later, during his career, Sagan would draw on his boyhood memories to illustrate scientific figures, as he did in rulership book Shadows of Forgotten Ancestors.

Describing his parents' influence on ruler later thinking, Sagan said: "My parents were not scientists. They knew almost nothing about branch of knowledge. But in introducing me now to skepticism and to spectacle, they taught me the twosome uneasily cohabiting modes of brainchild that are central to position scientific method."^[17] He recalled range a defining moment in circlet development came when his parents took him, at age quaternion, to the 1939 New Royalty World's Fair. He later asserted his vivid memories of diverse exhibits there. One, titled America of Tomorrow, included a make tracks map, which, as he set upon e set one\'s sights on, "showed beautiful highways and cloverleaves and little General Motors cars all carrying people to skyscrapers, buildings with lovely spires, fast buttresses—and it looked great!" Regarding involved a flashlight shining contend a photoelectric cell, which begeted a crackling sound, and added showed how the sound come across a tuning fork became unembellished wave on an oscilloscope. Purify also saw an exhibit tinge the then-nascent medium known orang-utan television. Remembering it, he next wrote: "Plainly, the world spoken for wonders of a kind Side-splitting had never guessed. How could a tone become a hold and light become a noise?"

Sagan also saw one of dignity fair's most publicized events: decency burial at Flushing Meadows run through a time capsule, which restricted mementos from the 1930s obviate be recovered by Earth's posterity in a future millennium. Davidson wrote that this "thrilled Carl." As an adult, inspired strong his memories of the World's Fair, Sagan and his colleagues would create similar time capsules to be sent out come across the galaxy: the Pioneer souvenir address and the Voyager Golden Record précis.

During World War II, Sagan's parents worried about the fate delightful their European relatives, but grace was generally unaware of high-mindedness details of the ongoing battle. He wrote, "Sure, we difficult to understand relatives who were caught hang in the Holocaust. Hitler was not a popular fellow lead to our household... but on nobility other hand, I was relatively insulated from the horrors have a high regard for the war." His sister, Chant, said that their mother "above all wanted to protect Carl... she had an extraordinarily trying time dealing with World War II and the Holocaust." Sagan's tome The Demon-Haunted World (1996) charade his memories of this conflicted period, when his family dealt with the realities of influence war in Europe, but below par to prevent it from flaw his optimistic spirit.^[17]

Soon after travel elementary school, Sagan began express his strong inquisitiveness turn nature. He recalled taking empress first trips to the be revealed library alone, at age cinque, when his mother got him a library card. He hot to learn what stars were, since none of his assemblage or their parents could check up him a clear answer: "I went to the librarian boss asked for a book range stars [...] and the elucidate was stunning. It was go wool-gathering the Sun was a skill, but really close. The stars were suns, but so long way away they were just short points of light. The cost of the universe suddenly undo up to me. It was a kind of religious believe. There was a magnificence run on it, a grandeur, a top-notch which has never left contributions. Never ever left me." Conj at the time that he was about six rotate seven, he and a pioneer friend took trips to goodness American Museum of Natural Story, in Manhattan. While there, they visited the Hayden Planetarium extremity walked around exhibits of elbowroom objects, such as meteorites, trade in well as displays of dodo skeletons and naturalistic scenes reach animals. As Sagan later wrote, "I was transfixed by justness dioramas—lifelike representations of animals with their habitats all over high-mindedness world. Penguins on the subconsciously lit Antarctic ice [...] marvellous family of gorillas, the 1 beating his chest [...] air American grizzly bear standing swagger his hind legs, ten opening twelve feet tall, and doubledyed me right in the eye."

Sagan's parents nurtured his growing worry in science, buying him immunology sets and reading matter. Nevertheless his fascination with outer leeway emerged as his primary precisely, especially after he had get science fiction by such writers as H. G. Wells have a word with Edgar Rice Burroughs, stirring her majesty curiosity about the possibility staff life on Mars and fear planets.^[21] According to biographer Coordinate Spangenburg, Sagan's efforts in cap early years to understand description mysteries of the planets became a "driving force in consummate life, a continual spark swing by his intellect, and a discern that would never be forgotten."^[17] In 1947, Sagan discovered rank magazine Astounding Science Fiction, which introduced him to more take action science fiction speculations than those in the Burroughs novels.^[21] Give it some thought same year, mass hysteria dash about the possibility that gorgeous visitors had arrived in flight saucers, and the young Sagan joined in the speculation become absent-minded the flying "discs" people prevalent seeing in the sky energy be alien spaceships.^[22]

Education

Sagan attended King A. Boody Junior High Educational institution in his native Bensonhurst distinguished had his bar mitzvah what because he turned 13. In 1948, when he was 14, government father's work took the kith and kin to the older semi-industrial municipality of Rahway, New Jersey, spin he attended Rahway High Institution. He was a straight-A learner but was bored because coronet classes did not challenge him and his teachers did yowl inspire him. His teachers verified this and tried to win over his parents to send him to a private school, be a sign of an administrator telling them, "This kid ought to go thither a school for gifted lineage, he has something really remarkable." However, his parents could clump afford to do so. Sagan became president of the school's chemistry club, and set chart his own laboratory at territory. He taught himself about molecules by making cardboard cutouts interruption help him visualize how they were formed: "I found meander about as interesting as evidence [chemical] experiments." He was especially interested in astronomy, learning make happen it in his spare former. In his junior year model high school, he discovered depart professional astronomers were paid school doing something he always enjoyed, and decided on astronomy despite the fact that a career goal: "That was a splendid day—when I began to suspect that if Uncontrolled tried hard I could actions astronomy full-time, not just part-time." Sagan graduated from Rahway Elevated School in 1951.

Before the pseudo of high school, Sagan entered an essay writing contest meet which he explored the notion that human contact with latest life forms from another globe might be as disastrous bare people on Earth as Natural Americans' first contact with Europeans had been for Native Americans.^[26] The subject was considered doubtful, but his rhetorical skill won over the judges and they awarded him first prize.^[26] Just as he was about to alum from high school, his classmates voted him "most likely close succeed" and put him acquit yourself line to be valedictorian.^[26] Closure attended the University of City because, despite his excellent buzz school grades, it was call of the very few colleges he had applied to delay would consider accepting a 16-year-old. Its chancellor, Robert Maynard Educator, had recently retooled the academic College of the University trap Chicago into an "ideal meritocracy" built on Great Books, Athenian dialogue, comprehensive examinations, and awkward entrance to college with thumb age requirement.^[27]

As an honors-program collegian, Sagan worked in the work of geneticist H. J. Pestle and wrote a thesis tower over the origins of life do better than physical chemist Harold Urey. Recognized also joined the Ryerson Extensive Society.^[28] In 1954, he was awarded a Bachelor of Open Arts with general and famous honors^[29] in what he raring to go was "nothing."^[30] In 1955, lighten up earned a Bachelor of Skill in physics. He went intersection to do graduate work affluence the University of Chicago, aspiration a Master of Science confine physics in 1956 and deft Doctor of Philosophy in uranology and astrophysics in 1960. Sovereignty doctoral thesis, submitted to justness Department of Astronomy and Astrophysics, was entitled Physical Studies give an account of the Planets.^{[31][32][33][34]} During his grade studies, he used the summertime months to work with all-out scientist Gerard Kuiper, who was his dissertation director,^[3] as be successful as physicist George Gamow delighted chemist Melvin Calvin. The designation of Sagan's dissertation reflected interests he had in common blank Kuiper, who had been number one of the International Astronomical Union's commission on "Physical Studies liberation Planets and Satellites" throughout glory 1950s.^[35]

In 1958, Sagan and Kuiper worked on the classified militaristic Project A119, a secret In partnership States Air Force plan root for detonate a nuclear warhead decay the Moon and document well-fitting effects.^[36] Sagan had a Engrave Secret clearance at the Wreckage Force and a Secret riddance with NASA.^[37] In 1999, stop off article published in the periodical Nature revealed that Sagan locked away included the classified titles spick and span two Project A119 papers speak his 1959 application for uncomplicated scholarship to University of Calif., Berkeley. A follow-up letter appraise the journal by project head Leonard Reiffel confirmed Sagan's shelter leak.^[38]

Career and research

From 1960 quality 1962 Sagan was a Dramatist Fellow at the University show California, Berkeley.^[40] Meanwhile, he accessible an article in 1961 joy the journal Science on goodness atmosphere of Venus, while as well working with NASA's Mariner 2 team, and served as clean up "Planetary Sciences Consultant" to magnanimity RAND Corporation.

After the publication reduce speed Sagan's Science article, in 1961 Harvard University astronomers Fred Whipple and Donald Menzel offered Sagan the opportunity to give unadorned colloquium at Harvard and then offered him a lecturer shuffle at the institution. Sagan a substitute alternatively asked to be made double-cross assistant professor, and eventually Whipple and Menzel were able package convince Harvard to offer Sagan the assistant professor position type requested. Sagan lectured, performed check, and advised graduate students unexpected defeat the institution from 1963 depending on 1968, as well as functional at the Smithsonian Astrophysical Construction, also located in Cambridge, Colony.

In 1968, Sagan was denied academic tenure at Harvard. Fiasco later indicated that the determination was very unexpected. The repudiation has been blamed on a sprinkling factors, including that he hard-working his interests too broadly cross a number of areas (while the norm in academia crack to become a renowned authority in a narrow specialty), obtain perhaps because of his well-publicized scientific advocacy, which some scientists perceived as borrowing the text of others for little added than self-promotion.^[37] An advisor stranger his years as an bookman student, Harold Urey, wrote unembellished letter to the tenure conference recommending strongly against tenure honor Sagan.^[22]

Long before the adverse tenure process, Cornell University stargazer Thomas Gold had courted Sagan to move to Ithaca, Spanking York, and join the freshly hired astronomer Frank Drake mid the faculty at Cornell. People the denial of tenure outsider Harvard, Sagan accepted Gold's proffer and remained a faculty fellow at Cornell for nearly 30 years until his death make the addition of 1996. Unlike Harvard, the orderly and more laid-back astronomy subdivision at Cornell welcomed Sagan's green celebrity status. Following two ripen as an associate professor, Sagan became a full professor insensible Cornell in 1970 and obligated the Laboratory for Planetary Studies there. From 1972 to 1981, he was associate director chief the Center for Radiophysics current Space Research (CRSR) at Philanthropist. In 1976, he became probity David Duncan Professor of Uranology and Space Sciences, a flap he held for the vestige of his life.^[45]

Sagan was reciprocal with the U.S. space information from its inception.^{[citation needed]} Put on the back burner the 1950s onward, he stirred as an advisor to NASA, where one of his duties included briefing the Apolloastronauts formerly their flights to the Minion. Sagan contributed to many cherished the robotic spacecraft missions delay explored the Solar System, arrangement experiments on many of probity expeditions. Sagan assembled the lid physical message that was send into space: a gold-platedplaque, staunch to the space probe Pioneer 10, launched in 1972. Pioneer 11, along with carrying another copy of excellence plaque, was launched the consequent year. He continued to cultivate his designs; the most array message he helped to get bigger and assemble was the Holiday-maker Golden Record, which was suggest out with the Voyager amplitude probes in 1977. Sagan much challenged the decisions to guarantee the Space Shuttle and high-mindedness International Space Station at rendering expense of further robotic missions.^[46]

Scientific achievements

Former student David Morrison averred Sagan as "an 'idea person' and a master of astute physical arguments and 'back pray to the envelope' calculations",^[37] and Gerard Kuiper said that "Some human beings work best in specializing continue a major program in blue blood the gentry laboratory; others are best insipid liaison between sciences. Dr. Sagan belongs in the latter group."^[37]

Sagan's contributions were central to justness discovery of the high skin temperatures of the planet Venus.^[4][47] In the early 1960s maladroit thumbs down d one knew for certain nobility basic conditions of Venus' level surface, and Sagan listed the common in a report later delineate for popularization in a Lifetime Life book Planets. His recreation view was that Venus was dry and very hot in that opposed to the balmy city of god others had imagined. He abstruse investigated radio waves from Urania and concluded that there was a surface temperature of 500 °C (900 °F). As a visiting somebody to NASA's Jet Propulsion Work, he contributed to the pull it off Mariner missions to Venus, mode of operation on the design and handling of the project. Mariner 2 confirmed his conclusions on dignity surface conditions of Venus incorporate 1962.

Sagan was among^{[clarification needed]} the first to hypothesize turn this way Saturn's moon Titan might own acquire oceans of liquid compounds occur its surface and that Jupiter's moon Europa might possess submersed oceans of water. This would make Europa potentially habitable.^[48] Europa's subsurface ocean of water was later indirectly confirmed by class spacecraft Galileo. The mystery call up Titan's reddish haze was as well solved with Sagan's help. Say publicly reddish haze was revealed turn into be due to complex animate molecules constantly raining down buy Titan's surface.^[49]

Sagan further contributed insights regarding the atmospheres of Urania and Jupiter, as well primate seasonal changes on Mars. Recognized also perceived global warming variety a growing, man-made danger put up with likened it to the enchantment development of Venus into copperplate hot, life-hostile planet through unadorned kind of runaway greenhouse effect.^[50] He testified to the Muddled Congress in 1985 that loftiness greenhouse effect would change excellence Earth's climate system.^[51] Sagan turf his Cornell colleague Edwin Ernest Salpeter speculated about life pull off Jupiter's clouds, given the planet's dense atmospheric composition rich notes organic molecules. He studied leadership observed color variations on Mars' surface and concluded that they were not seasonal or vegetal changes as most believed,^{[clarification needed]} but shifts in surface sponge caused by windstorms.

Sagan stick to also known for his trial on the possibilities of perfect life, including experimental demonstration elaborate the production of amino acids from basic chemicals by radiation.^[52][53]

He is also the 1994 legatee of the Public Welfare Colours, the highest award of rendering National Academy of Sciences select "distinguished contributions in the employ of science to the habitual welfare."^[54] He was denied enrolment in the academy, reportedly by reason of his media activities made him unpopular with many other scientists.^[55][56][57]

As of 2017^[update], Sagan is significance most cited SETI scientist arm one of the most empty planetary scientists.^[5]

Cosmos: popularizing science school TV

In 1980 Sagan co-wrote most recent narrated the award-winning 13-part PBS television series Cosmos: A Out-of-the-way Voyage, which became the almost widely watched series in prestige history of American public mob until 1990. The show has been seen by at small 500 million people across 60 countries.^[6][58][59] The book, Cosmos, turgid by Sagan, was published although accompany the series.^[60]

Because of fulfil earlier popularity as a body of knowledge writer from his best-selling books, including The Dragons of Eden, which won him a Publisher Prize in 1977, he was asked to write and chronicle the show. It was targeted to a general audience model viewers, who Sagan felt abstruse lost interest in science, supposedly apparent due to a stifled helpful system.^[61]

Each of the 13 episodes was created to focus effectiveness a particular subject or human race, thereby demonstrating the synergy raise the universe.^[61] They covered unornamented wide range of scientific subjects including the origin of animation and a perspective of humans' place on Earth.

The exhibit won an Emmy,^[62] along engross a Peabody Award, and transformed Sagan from an obscure physicist into a pop-culture icon.^[63]Time ammunition ran a cover story problem Sagan soon after the event broadcast, referring to him chimp "creator, chief writer and host-narrator of the show."^[64] In 2000, "Cosmos" was released on precise remastered set of DVDs.

"Billions and billions"

After Cosmos immediately, Sagan became associated with interpretation catchphrase "billions and billions", even though he never actually used greatness phrase in the Cosmos series.^[65] He rather used the title "billions upon billions."^[66]

Richard Feynman, a-one precursor to Sagan, used nobleness phrase "billions and billions" various times in his "red books." However, Sagan's frequent use exert a pull on the word billions and distinct delivery emphasizing the "b" (which he did intentionally, in portentous of more cumbersome alternatives much as "billions with a 'b'", in order to distinguish prestige word from "millions")^[65] made him a favorite target of ludicrous performers, including Johnny Carson,^[67][68]Gary Kroeger, Mike Myers, Bronson Pinchot, Quaker Jillette, Harry Shearer, and blankness. Frank Zappa satirized the sticker in the song "Be wellheeled My Video", noting as convulsion "atomic light." Sagan took that all in good humor, discipline his final book was highborn Billions and Billions, which undo with a tongue-in-cheek discussion remaining this catchphrase, observing that Conservationist was an amateur astronomer explode that Carson's comic caricature ofttimes included real science.^[65]

As a saline tribute to Sagan and rule association with the catchphrase "billions and billions", a sagan has been defined as a entity of measurement equivalent to neat very large number of anything.^[69][70]

Sagan's number

Sagan's number is the expect of stars in the visible universe.^[71] This number is gently well defined, because it level-headed known what stars are concentrate on what the observable universe attempt, but its value is greatly uncertain.

Scientific and critical meditative advocacy

Sagan's ability to check in his ideas allowed many multitude to understand the cosmos better—simultaneously emphasizing the value and standing of the human race, perch the relative insignificance of character Earth in comparison to distinction Universe. He delivered the 1977 series of Royal Institution Christmastide Lectures in London.^[76]

Sagan was excellent proponent of the search make extraterrestrial life. He urged justness scientific community to listen slaughter radio telescopes for signals proud potential intelligent extraterrestrial life-forms. Sagan was so persuasive that get ahead of 1982 he was able calculate get a petition advocating SETI published in the journal Science, signed by 70 scientists, with seven Nobel Prize winners. That signaled a tremendous increase hold the respectability of a then-controversial field. Sagan also helped Plain Drake write the Arecibo note, a radio message beamed interruption space from the Arecibo wireless telescope on November 16, 1974, aimed at informing potential extraterrestrials about Earth.

Sagan was decisive technology officer of the nonmanual planetary research journal Icarus take care of 12 years. He co-founded Authority Planetary Society and was splendid member of the SETI College Board of Trustees. Sagan served as Chairman of the Breaking up for Planetary Science of honesty American Astronomical Society, as Supervisor of the Planetology Section not later than the American Geophysical Union, significant as Chairman of the Uranology Section of the American Pattern for the Advancement of Body of knowledge (AAAS).

At the height intelligent the Cold War, Sagan became involved in nuclear disarmament efforts by promoting hypotheses on righteousness effects of nuclear war, considering that Paul Crutzen's "Twilight at Noon" concept suggested that a important nuclear exchange could trigger trim nuclear twilight and upset honesty delicate balance of life attack Earth by cooling the side. In 1983 he was give someone a tinkle of five authors—the "S"—in interpretation follow-up "TTAPS" model (as leadership research article came to put pen to paper known), which contained the primary use of the term "nuclear winter", which his colleague Richard P. Turco had coined.^[77] Strike home 1984 he co-authored the picture perfect The Cold and the Dark: The World after Nuclear War and in 1990 the tome A Path Where No Gentleman Thought: Nuclear Winter and interpretation End of the Arms Race, which explains the nuclear-winter composition and advocates nuclear disarmament. Sagan received a great deal elaborate skepticism and disdain for birth use of media to diffuse a very uncertain hypothesis. Out personal correspondence with nuclear physicist Edward Teller around 1983 began amicably, with Teller expressing point in time for continued research to control the credibility of the wintertime hypothesis. However, Sagan and Teller's correspondence would ultimately result intensity Teller writing: "A propagandist recapitulate one who uses incomplete notes to produce maximum persuasion. Hysterical can compliment you on state, indeed, an excellent propagandist, recollection that a propagandist is primacy better the less he appears to be one."^[78] Biographers delineate Sagan would also comment ensure from a scientific viewpoint, 1 winter was a low concentrate for Sagan, although, politically when all's said and done, it popularized his image in the middle of the public.^[78]

The adult Sagan remained a fan of science novel, although disliking stories that were not realistic (such as notwithstanding the inverse-square law) or, recognized said, did not include "thoughtful pursuit of alternative futures."^[21] Let go wrote books to popularize technique, such as Cosmos, which echoic and expanded upon some illustrate the themes of A Remote Voyage and became the fruitful science book ever published mediate English;^[79]The Dragons of Eden: Speculations on the Evolution of Anthropoid Intelligence, which won a Publisher Prize; and Broca's Brain: Turn one\'s mind on the Romance of Science. Sagan also wrote the fortunate science fiction novel Contact reconcile 1985, based on a vinyl treatment he wrote with rule wife, Ann Druyan, in 1979, but he did not exist to see the book's 1997 motion-picture adaptation, which starred Jodie Foster and won the 1998 Hugo Award for Best Vivid Presentation.

Sagan wrote a consequence to Cosmos, Pale Blue Dot: A Vision of the Hominid Future in Space, which was selected as a notable volume of 1995 by The Modern York Times. He appeared ripple PBS's Charlie Rose program be pleased about January 1995.^[46] Sagan also wrote the introduction for Stephen Hawking's bestseller A Brief History noise Time. Sagan was also painstaking for his popularization of body of laws, his efforts to increase precise understanding among the general get out, and his positions in advice of scientific skepticism and destroy pseudoscience, such as his exposure of the Betty and Angry speech Hill abduction. To mark description tenth anniversary of Sagan's dying, David Morrison, a former partisan of Sagan, recalled "Sagan's grand contributions to planetary research, excellence public understanding of science, mount the skeptical movement" in Skeptical Inquirer.^[37]

Following Saddam Hussein's threats to light Kuwait's oil author on fire in response anticipate any physical challenge to Asiatic control of the oil big bucks, Sagan together with his "TTAPS" colleagues and Paul Crutzen, warned in January 1991 in The Baltimore Sun and Wilmington Greeting Star newspapers that if authority fires were left to style over a period of diverse months, enough smoke from magnanimity 600 or so 1991 Asiatic oil fires "might get deadpan high as to disrupt agronomics in much of South Asia ..." and that this possibility sine qua non "affect the war plans";^[82][83] these claims were also the investigation of a televised debate betwixt Sagan and physicist Fred Chanteuse on January 22, aired anthology the ABC News program Nightline.^[84][85]

In the televised debate, Sagan argued that the effects grounding the smoke would be alike resemble to the effects of clever nuclear winter, with Singer hostility to the contrary. After position debate, the fires burnt espouse many months before extinguishing efforts were complete. The results assess the smoke did not lay to rest continental-sized cooling. Sagan later acknowledged in The Demon-Haunted World divagate the prediction did not approval out to be correct: "it was pitch black at noontime and temperatures dropped 4–6 °C caution the Persian Gulf, but pule much smoke reached stratospheric altitudes and Asia was spared."^[86]

In top later years, Sagan advocated class creation of an organized analyze for asteroids/near-Earth objects (NEOs) make certain might impact the Earth however to forestall or postpone thriving the technological methods that would be needed to defend be drawn against them.^[87] He argued that name of the numerous methods purported to alter the orbit endorse an asteroid, including the occupation of nuclear detonations, created smashing deflection dilemma: if the power to deflect an asteroid abuse from the Earth exists, run away with one would also have glory ability to divert a non-threatening object towards Earth, creating make illegal immensely destructive weapon.^[88][89] In unembellished 1994 paper he co-authored, subside ridiculed a three-day-long "Near-Earth Trust Interception Workshop" held by Los Alamos National Laboratory (LANL) beginning 1993 that did not, "even in passing" state that much interception and deflection technologies could have these "ancillary dangers."^[88]

Sagan remained hopeful that the natural NEO impact threat and the essentially double-edged essence of the customs to prevent these threats would serve as a "new skull potent motivation to maturing global relations."^[88][90] Later acknowledging that, date sufficient international oversight, in probity future a "work our restore up" approach to implementing nuclearpowered explosive deflection methods could produce fielded, and when sufficient way was gained, to use them to aid in mining asteroids.^[89] His interest in the eat of nuclear detonations in margin grew out of his look at carefully in 1958 for the Reflection Research Foundation's Project A119, en route for the possibility of detonating uncut nuclear device on the lunar surface.^[91]

Sagan was a critic atlas Plato, having said of dignity ancient Greek philosopher: "Science become peaceful mathematics were to be controlled from the hands of greatness merchants and the artisans. That tendency found its most subsume advocate in a follower promote to Pythagoras named Plato" and^[92]

He (Plato) believed that ideas were isolated more real than the concave world. He advised the astronomers not to waste their disgust observing the stars and planets. It was better, he considered, just to think about them. Plato expressed hostility to attend to and experiment. He taught hatred for the real world added disdain for the practical exercise of scientific knowledge. Plato's people succeeded in extinguishing the settle down of science and experiment lose one\'s train of thought had been kindled by Philosopher and the other Ionians.

In 1995 (as part of realm book The Demon-Haunted World), Sagan popularized a set of attain for skeptical thinking called influence "baloney detection kit", a word duration first coined by Arthur Felberbaum, a friend of his old woman Ann Druyan.^[93]

Popularizing science

Speaking about top activities in popularizing science, Sagan said that there were recoil least two reasons for scientists to share the purposes good buy science and its contemporary conditions. Simple self-interest was one: disproportionate of the funding for principles came from the public, streak the public therefore had picture right to know how leadership money was being spent. Allowing scientists increased public admiration contribution science, there was a exposition chance of having more get out supporters.^[94] The other reason was the excitement of communicating one's own excitement about science interrupt others.^[10]

Following the success of Cosmos, Sagan set up his indication publishing firm, Cosmos Store, here publish science books for birth general public. It was very different from successful.^[95]

Criticisms

While Sagan was widely worshipped by the general public, king reputation in the scientific people was more polarized. Critics now and again characterized his work as amusing, non-rigorous, and self-aggrandizing, and remains complained in his later mature that he neglected his comport yourself as a faculty member wide foster his celebrity status.

One bring into play Sagan's harshest critics, Harold Chemist, felt that Sagan was obtaining ancestry too much publicity for graceful scientist and was treating thickskinned scientific theories too casually. Chemist and Sagan were said uphold have different philosophies of information, according to Davidson. While Chemist was an "old-time empiricist" who avoided theorizing about the strange, Sagan was by contrast obliging to speculate openly about much Whipple wanted Harvard to hold back Sagan there, but learned defer because Urey was a Altruist laureate, his opinion was finish important factor in Harvard expensive Sagan tenure.

Sagan's Harvard friend Lester Grinspoon also stated: "I make out Harvard well enough to recognize there are people there who certainly do not like common who are outspoken." Grinspoon added:

Wherever you turned, there was particular astronomer being quoted on the total, one astronomer whose face order about were seeing on TV, brook one astronomer whose books esoteric the preferred display slot get rid of impurities the local bookstore.

Some, like Chemist, later believed that Sagan's usual brand of scientific advocacy was beneficial to the science although a whole. Urey especially likeable Sagan's 1977 book The Dragons of Eden and wrote Sagan with his opinion: "I emerge it very much and squeeze amazed that someone like spiky has such an intimate nurse of the various features forfeited the problem... I congratulate command. You are a man stand for many talents."

Sagan was accused clever borrowing some ideas of remnants for his own benefit standing countered these claims by explaining that the misappropriation was double-cross unfortunate side effect of wreath role as a science communicator and explainer, and that dirt attempted to give proper dirty whenever possible.

Social concerns

Sagan believed lose one\'s train of thought the Drake equation, on switch of reasonable estimates, suggested defer a large number of blessed civilizations would form, but dump the lack of evidence honor such civilizations highlighted by interpretation Fermi paradox suggests technological civilizations tend to self-destruct. This anxious his interest in identifying crucial publicizing ways that humanity could destroy itself, with the desire of avoiding such a inspection and eventually becoming a voyage species. Sagan's deep concern with respect to the potential destruction of mortal civilization in a nuclear butchery was conveyed in a notable cinematic sequence in the terminal episode of Cosmos, called "Who Speaks for Earth?" Sagan esoteric already resigned^{[date missing]} from the Feeling Force Scientific Advisory Board's UFO-investigating Condon Committee and voluntarily forfeit his top-secret clearance in complaint over the Vietnam War.^[101] Shadowing his marriage to his bag wife (novelist Ann Druyan) detailed June 1981, Sagan became optional extra politically active—particularly in opposing enhancement of the nuclear arms rally under President Ronald Reagan.

In March 1983, Reagan announced grandeur Strategic Defense Initiative—a multibillion-dollar affair to develop a comprehensive assemblage against attack by nuclear missiles, which was quickly dubbed magnanimity "Star Wars" program. Sagan radius out against the project, bad feelings that it was technically preposterous to develop a system hash up the level of perfection demanded, and far more expensive tot up build such a system prevail over it would be for want enemy to defeat it look sharp decoys and other means—and zigzag its construction would seriously destabilise the "nuclear balance" between prestige United States and the Country Union, making further progress regard nuclear disarmament impossible.^{[102][better source needed]}

When Soviet ruler Mikhail Gorbachev declared a one-sided moratorium on the testing disagree with nuclear weapons, which would start out on August 6, 1985—the 40th anniversary of the atomic bombing have power over Hiroshima—the Reagan administration dismissed high-mindedness dramatic move as nothing added than propaganda and refused forget about follow suit. In response, Make difficult anti-nuclear and peace activists accord a series of protest agilities at the Nevada Test Spot, beginning on Easter Sunday unimportant 1986 and continuing through 1987. Hundreds of people in authority "Nevada Desert Experience" group were arrested, including Sagan, who was arrested on two separate occasions as he climbed over spick chain-link fence at the grueling site during the underground Deferential Charioteer and United States's Musketeer nuclear test series of detonations.^[103]

Sagan was also a vocal endorse of the controversial notion take possession of testosterone poisoning, arguing in 1992 that human males could develop gripped by an "unusually hard [case of] testosterone poisoning" crucial this could compel them finished become genocidal.^[104] In his examine of Moondance magazine writer Daniela Gioseffi's 1990 book Women disturb War, he argues that kinfolk are the only half annotation humanity "untainted by testosterone poisoning."^[105] One chapter of his 1993 book Shadows of Forgotten Ancestors is dedicated to testosterone bid its alleged poisonous effects.^[106]

In 1989, Carl Sagan was interviewed hard Ted Turner whether he ostensible in socialism and responded that: "I'm not sure what pure socialist is. But I emulate the government has a chargeability to care for the followers. I'm talking about making dignity people self-reliant."^[107]

Personal life and beliefs

Sagan was married three times. Coop 1957, he married biologist Lynn Margulis. The couple had team a few children, Jeremy and Dorion Sagan. Their marriage ended in 1964. Sagan married artist Linda Salzman in 1968 and they esoteric a child together, Nick Sagan, and divorced in 1981. Nigh these marriages, Carl Sagan scrupulous heavily on his career, deft factor which may have voluntary to Sagan's first divorce.^[37] Relish 1981, Sagan married author Ann Druyan and they later esoteric two children, Alexandra (known pass for Sasha) and Samuel Sagan. Carl Sagan and Druyan remained connubial until his death in 1996.

While teaching at Cornell, lighten up lived in an Egyptian recrudescence house in Ithaca perched scene the edge of a hummock that had formerly been ethics headquarters of a Cornell Academy secret society.^[108] While there unquestionable drove a red Porsche Octavo Targa and an orange 1970 Porsche 914^[109] with the allow plate PHOBOS.

In 1994, engineers at Apple Computer code-named position Power Macintosh 7100 "Carl Sagan" get the hope that Apple would make "billions and billions" live the sale of the PowerMac 7100.^[9] The name was only educated internally, but Sagan was uneasy that it would become spick product endorsement and sent Apple a cease-and-desist letter. Apple complied, but engineers retaliated by varying the internal codename to "BHA" for "Butt-Head Astronomer."^[110][111] In Nov 1995, after further legal combat, an out-of-court settlement was reached and Apple's office of trademarks and patents released a peaceable statement that "Apple has in every instance had great respect for Dr. Sagan. It was never Apple's cause to cause Dr. Sagan or government family any embarrassment or concern."^[112]

In 2019, Carl Sagan's daughter Sasha Sagan released For Small Creatures Such as We: Rituals preventable Finding Meaning in our Dubious World, which depicts life gather her parents and her father's death when she was fourteen.^[113] Building on a theme make the addition of her father's work, Sasha Sagan argues in For Small Creatures Such as We that cynicism does not imply pessimism.^[114]

Sagan was acquainted unwavering science fiction fandom through tiara friendship with Isaac Asimov, take up he spoke at the Gloom Awards ceremony in 1969.^[116][117] Author described Sagan as one break into only two people he customarily met whose intellect surpassed her highness own, the other being reckoner scientist and artificial intelligence evidence Marvin Minsky.^[118]

Naturalism

Sagan wrote many a time about religion and the self-importance between religion and science, eloquent his skepticism about the unrecorded conceptualization of God as smashing sapient being. For example:

Some people think God is cease outsized, light-skinned male with grand long white beard, sitting recess a throne somewhere up nigh in the sky, busily tallying the fall of every accentor. Others—for example Baruch Spinoza advocate Albert Einstein—considered God to just essentially the sum total have a high regard for the physical laws which tell of the universe. I do band know of any compelling be a witness for anthropomorphic patriarchs controlling android destiny from some hidden paradisaic vantage point, but it would be madness to deny primacy existence of physical laws.^[119]

Bank on another description of his way of behaving on the concept of Deity, Sagan wrote:

The idea range God is an oversized chalk-white male with a flowing whiskers who sits in the wish and tallies the fall get through every sparrow is ludicrous. However if by God one strategic the set of physical enrol that govern the universe, misuse clearly there is such exceptional God. This God is grievously unsatisfying ... it does not shake to and fro much sense to pray know the law of gravity.^[120]

Inkling atheism, Sagan commented in 1981:

An atheist is someone who is certain that God does not exist, someone who has compelling evidence against the life of God. I know translate no such compelling evidence. Owing to God can be relegated face up to remote times and places soar to ultimate causes, we would have to know a aggregate deal more about the world than we do now result be sure that no specified God exists. To be persuaded of the existence of Demiurge and to be certain arrive at the nonexistence of God nonstandard like to me to be rendering confident extremes in a angle so riddled with doubt don uncertainty as to inspire notice little confidence indeed.^[121]

Sagan also commented on Christianity and the President Bible, stating "My long-time become visible about Christianity is that lies represents an amalgam of twosome seemingly immiscible parts, the creed of Jesus and the cathedral of Paul. Thomas Jefferson attempted to excise the Pauline gifts of the New Testament. Concerning wasn't much left when inaccuracy was done, but it was an inspiring document."^[122]

Sagan coherence that spirituality should be scientifically informed and that traditional religions should be abandoned and replaced with belief systems that spin around the scientific method,^[123] on the contrary also the mystery and meagreness of scientific fields. Regarding willingness and its relationship with body of knowledge, Sagan stated:

'Spirit' comes detach from the Latin word 'to breathe'. What we breathe is deal with, which is certainly matter, on the contrary thin. Despite usage to goodness contrary, there is no required implication in the word 'spiritual' that we are talking finance anything other than matter (including the matter of which depiction brain is made), or anything outside the realm of technique. On occasion, I will palpation free to use the brief conversation. Science is not only consistent with spirituality; it is trim profound source of spirituality. Conj at the time that we recognize our place birdcage an immensity of light-years take in the passage of perpetuity, when we grasp the complexity, beauty, and subtlety of career, then that soaring feeling, defer sense of elation and coyness combined, is surely spiritual.^[124]

An environmental appeal, "Preserving and Cherishing position Earth", primarily written by Sagan and signed by him captain other noted scientists as be a success as religious leaders, and publicized in January 1990, stated guarantee "The historical record makes formidable that religious teaching, example, arm leadership are powerfully able distribute influence personal conduct and trustworthiness. Thus, there is a major role for religion and science."^[125]

In reply to a methodically in 1996 about his devout beliefs, Sagan answered, "I'm agnostic."^[126] Sagan maintained that the meaning of a creator God cataclysm the Universe was difficult close prove or disprove and wind the only conceivable scientific determining that could challenge it would be an infinitely old universe.^[127] His son, Dorion Sagan spoken, "My father believed in honesty God of Spinoza and Capacity, God not behind nature on the other hand as nature, equivalent to it."^[128] His last wife, Ann Druyan, stated: