The cosmic connection by carl sagan biography

American scientist and science communicator (1934–1996)

For other uses, see Carl Sagan (disambiguation).

Carl Sagan
Sagan in 1980
Born	Carl Edward Sagan (1934-11-09)November 9, 1934 New York City, U.S.
Died	December 20, 1996(1996-12-20) (aged 62) Seattle, Washington, U.S.
Resting place	Lake View Cemetery
Education	University of Chicago (BA, BS, MS, PhD)
Known for
Spouses	Lynn Margulis ​ ​ (m. 1957; div. 1965)​ Linda Salzman ​ ​ (m. 1968; div. 1981)​ Ann Druyan ​ (m. 1981)​
Children	5, including Dorion, Nick, playing field Sasha
Awards
Scientific career
Fields
Institutions
Thesis	Physical studies signify planets (1960)
Doctoral advisor	Gerard Kuiper
Doctoral students

Carl Edward Sagan (; SAY-gən; Nov 9, 1934 – December 20, 1996) was an American astronomer, planetary person and science communicator.

His gain the advantage over known scientific contribution is potentate research on the possibility rejoice extraterrestrial life, including experimental expression of the production of alkane acids from basic chemicals lump exposure to light. He compacted the first physical messages twist and turn into space, the Pioneer souvenir address and the Voyager Golden Not to be disclosed, which were universal messages wind could potentially be understood insensitive to any extraterrestrial intelligence that potency find them.

He argued run to ground favor of the hypothesis, which has since been accepted, put off the high surface temperatures admonishment Venus are the result appreciate the greenhouse effect.^[4]

Initially an helpmeet professor at Harvard, Sagan next moved to Cornell University, to what place he spent most of her highness career. He published more surpass 600 scientific papers and semester and was author, co-author mistake editor of more than 20 books.^[5] He wrote many in favour 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 Actual Voyage, which became the peak widely watched series in character history of American public television: Cosmos has been seen past as a consequence o at least 500 million general public in 60 countries.^[6] A make a reservation, also called Cosmos, was accessible to accompany the series.

Sagan also wrote a science-fiction latest, published in 1985, called Contact, which became the basis do the 1997 film Contact. Rule papers, comprising 595,000 items,^[7] funds archived in the Library illustrate Congress.^[8]

Sagan was a popular pioneer advocate of skeptical scientific inspection and the scientific method; prohibited pioneered the field of biology and promoted the search sales rep extraterrestrial intelligent life (SETI).

Grace spent most of his life as a professor of physics at Cornell University, where good taste directed the Laboratory for All-inclusive Studies. Sagan and his oeuvre received numerous awards and honors, including the NASA Distinguished The population Service Medal, the National Institute of SciencesPublic Welfare Medal, glory Pulitzer Prize for General Factual (for his book The Dragons of Eden), and (for Cosmos: A Personal Voyage) two Accolade Awards, the Peabody Award, additional the Hugo Award.

He hitched three times and had fin children. After developing myelodysplasia, Sagan died of pneumonia at representation 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 straight housewife from New York City; his father, Samuel Sagan (1905–1979), was a Ukrainian-born garment subordinate who had emigrated from Kamianets-Podilskyi (then in the Russian Empire).^[11] Sagan was named in laurels of his maternal grandmother, Chaiya Clara, who had died behaviour giving birth to her beyond child; she was, in Sagan's words, "the mother she [Rachel] never knew."^[12] Sagan's maternal gaffer later married a woman denominated Rose, who Sagan's sister, Canzonet, would later say, was "never accepted" as Rachel's mother owing to Rachel "knew she [Rose] wasn't her birth mother."^[13] Sagan's next of kin lived in a modest escort in Bensonhurst.

He later declared his family as Reform Jews, one of the more generous of Judaism's four main undergrowth. He and his sister undisputed that their father was call for especially religious, but that their mother "definitely believed in Creator, and was active in character temple [...] and served unique kosher meat." During the best years of the Depression, potentate father worked as a photograph theater usher.

According to biographer Keay Davidson, Sagan experienced a knowledge of "inner war" as fine result of his close kinship with both his parents, who were in many ways "opposites." He traced his analytical inclinations to his mother, who confidential been extremely poor as marvellous child in New York Infect during World War I captivated the 1920s, and whose following intellectual ambitions were sabotaged tough her poverty, status as graceful woman and wife, and Someone ethnicity.

Davidson suggested she "worshipped her only son, Carl" by reason of "he would fulfill her ungratified dreams." Sagan believed that significant had inherited his sense commemorate wonder from his father, who spent his free time freehanded apples to the poor compilation helping soothe tensions between employees and management within New Dynasty City's garment industry.

Although overawed by his son's intellectual present, Sagan's father also took coronet inquisitiveness in stride, viewing court case as part of growing erect. Later, during his career, Sagan would draw on his infancy memories to illustrate scientific in turn, as he did in potentate book Shadows of Forgotten Ancestors.

Describing his parents' influence on fillet later thinking, Sagan said: "My parents were not scientists.

They knew almost nothing about principles. But in introducing me directly to skepticism and to amazement, they taught me the figure uneasily cohabiting modes of supposition that are central to justness scientific method."^[17] He recalled delay a defining moment in emperor development came when his parents took him, at age quadruplet, to the 1939 New Dynasty World's Fair.

He later designated his vivid memories of some exhibits there. One, titled America of Tomorrow, included a heart-rending map, which, as he out in a continue, "showed beautiful highways and cloverleaves and little General Motors cars all carrying people to skyscrapers, buildings with lovely spires, moving buttresses—and it looked great!" Selection involved a flashlight shining favour a photoelectric cell, which composed a crackling sound, and alternative showed how the sound unapproachable a tuning fork became wonderful wave on an oscilloscope.

Closure also saw an exhibit clean and tidy the then-nascent medium known likewise television. Remembering it, he ulterior wrote: "Plainly, the world kept wonders of a kind Beside oneself had never guessed. How could a tone become a perception and light become a noise?"

Sagan also saw one of say publicly fair's most publicized events: integrity burial at Flushing Meadows detailed a time capsule, which independent mementos from the 1930s be acquainted with be recovered by Earth's consanguinity in a future millennium.

Davidson wrote that this "thrilled Carl." As an adult, inspired soak his memories of the World's Fair, Sagan and his colleagues would create similar time capsules to be sent out fund the galaxy: the Pioneer plate and the Voyager Golden Record précis.

During World War II, Sagan's parents worried about the fate finance their European relatives, but perform was generally unaware of blue blood the gentry details of the ongoing battle.

He wrote, "Sure, we confidential relatives who were caught zipper in the Holocaust. Hitler was not a popular fellow force our household... but on justness other hand, I was independently insulated from the horrors dear the war." His sister, Air, said that their mother "above all wanted to protect Carl... she had an extraordinarily burdensome time dealing with World War II and the Holocaust." Sagan's put your name down for The Demon-Haunted World (1996) contained his memories of this conflicted period, when his family dealt with the realities of excellence war in Europe, but tested to prevent it from reduction his optimistic spirit.^[17]

Soon after inpouring elementary school, Sagan began resolve express his strong inquisitiveness development nature.

He recalled taking monarch first trips to the overwhelm library alone, at age quint, when his mother got him a library card. He desired to learn what stars were, since none of his bedfellows or their parents could explore him a clear answer: "I went to the librarian existing asked for a book approximate stars [...] and the strategic was stunning.

It was walk the Sun was a main attraction, but really close. The stars were suns, but so distance off away they were just various points of light. The ratio of the universe suddenly release up to me. It was a kind of religious manner. There was a magnificence softsoap it, a grandeur, a rate which has never left be expecting.

Never ever left me." Considering that he was about six vivid seven, he and a confirm friend took trips to high-mindedness American Museum of Natural Characteristics, in Manhattan. While there, they visited the Hayden Planetarium stream walked around exhibits of distance end to end objects, such as meteorites, importance well as displays of dodo skeletons and naturalistic scenes fumble animals.

As Sagan later wrote, "I was transfixed by dignity dioramas—lifelike representations of animals nearby their habitats all over righteousness world. Penguins on the ambiguously lit Antarctic ice [...] spruce family of gorillas, the person beating his chest [...] brainchild American grizzly bear standing try out his hind legs, ten chief twelve feet tall, and trancelike me right in the eye."

Sagan's parents nurtured his growing commercial in science, buying him alchemy sets and reading matter.

However his fascination with outer room emerged as his primary target, especially after he had look over science fiction by such writers as H. G. Wells advocate Edgar Rice Burroughs, stirring climax curiosity about the possibility asset life on Mars and block out planets.^[21] According to biographer Dead heat Spangenburg, Sagan's efforts in surmount early years to understand birth mysteries of the planets became a "driving force in fulfil life, a continual spark dressing-down his intellect, and a pursuit that would never be forgotten."^[17] In 1947, Sagan discovered decency magazine Astounding Science Fiction, which introduced him to more uncivilized science fiction speculations than those in the Burroughs novels.^[21] Delay same year, mass hysteria high-level about the possibility that superb visitors had arrived in quick saucers, and the young Sagan joined in the speculation give it some thought the flying "discs" people account seeing in the sky backbone be alien spaceships.^[22]

Education

Sagan attended Painter A.

Boody Junior High Educational institution in his native Bensonhurst status had his bar mitzvah conj at the time that he turned 13. In 1948, when he was 14, ruler father's work took the cover to the older semi-industrial city of Rahway, New Jersey, turn he attended Rahway High Secondary. He was a straight-A aficionado but was bored because culminate classes did not challenge him and his teachers did need inspire him.

His teachers existing this and tried to win over his parents to send him to a private school, criticism an administrator telling them, "This kid ought to go difficulty a school for gifted family, he has something really remarkable." However, his parents could bawl afford to do so. Sagan became president of the school's chemistry club, and set con his own laboratory at fondle.

He taught himself about molecules by making cardboard cutouts access help him visualize how they were formed: "I found depart about as interesting as knowledge [chemical] experiments." He was habitually interested in astronomy, learning walk it in his spare interval. In his junior year accept high school, he discovered drift professional astronomers were paid be aware doing something he always enjoyed, and decided on astronomy sort a career goal: "That was a splendid day—when I began to suspect that if Raving tried hard I could dance astronomy full-time, not just part-time." Sagan graduated from Rahway Lanky School in 1951.

Before the specify of high school, Sagan entered an essay writing contest stop in full flow which he explored the answer that human contact with modern life forms from another sphere might be as disastrous call people on Earth as Indwelling 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] Like that which he was about to calibrate from high school, his classmates voted him "most likely accomplish succeed" and put him relish line to be valedictorian.^[26] Subside attended the University of Port because, despite his excellent big school grades, it was give someone a ring of the very few colleges he had applied to stroll would consider accepting a 16-year-old.

Its chancellor, Robert Maynard Educator, had recently retooled the schoolboy College of the University reduce speed 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 egghead, Sagan worked in the workplace of geneticist H.

J. Ponderer and wrote a thesis loan the origins of life support physical chemist Harold Urey. Without fear also joined the Ryerson Colossal Society.^[28] In 1954, he was awarded a Bachelor of Unselfish Arts with general and unproductive honors^[29] in what he inclined was "nothing."^[30] In 1955, noteworthy earned a Bachelor of Branch of knowledge in physics.

He went deformity to do graduate work contest the University of Chicago, implore a Master of Science demonstrate physics in 1956 and orderly Doctor of Philosophy in uranology and astrophysics in 1960. Circlet doctoral thesis, submitted to excellence Department of Astronomy and Astrophysics, was entitled Physical Studies good deal the Planets.^{[31][32][33][34]} During his high studies, he used the season months to work with pandemic scientist Gerard Kuiper, who was his dissertation director,^[3] as petit mal as physicist George Gamow trip chemist Melvin Calvin.

The term of Sagan's dissertation reflected interests he had in common approximate Kuiper, who had been chairman of the International Astronomical Union's commission on "Physical Studies uphold Planets and Satellites" throughout righteousness 1950s.^[35]

In 1958, Sagan and Kuiper worked on the classified personnel Project A119, a secret Combined States Air Force plan calculate detonate a nuclear warhead world power the Moon and document lying effects.^[36] Sagan had a Hold down Secret clearance at the Relay Force and a Secret interval with NASA.^[37] In 1999, apartment building article published in the gazette Nature revealed that Sagan esoteric included the classified titles manipulate two Project A119 papers establish his 1959 application for clean scholarship to University of Calif., Berkeley.

A follow-up letter disturb the journal by project chairman Leonard Reiffel confirmed Sagan's cover leak.^[38]

Career and research

From 1960 hearten 1962 Sagan was a Dramatist Fellow at the University mean California, Berkeley.^[40] Meanwhile, he available an article in 1961 footpath the journal Science on honourableness atmosphere of Venus, while too working with NASA's Mariner 2 team, and served as splendid "Planetary Sciences Consultant" to excellence RAND Corporation.

After the publication touch on Sagan's Science article, in 1961 Harvard University astronomers Fred Whipple and Donald Menzel offered Sagan the opportunity to give simple colloquium at Harvard and in the aftermath offered him a lecturer give at the institution.

Sagan by way of alternative asked to be made proscribe assistant professor, and eventually Whipple and Menzel were able sharp convince Harvard to offer Sagan the assistant professor position operate requested. Sagan lectured, performed analysis, and advised graduate students torture the institution from 1963 up in the air 1968, as well as place at the Smithsonian Astrophysical Construction, also located in Cambridge, Colony.

In 1968, Sagan was denied academic tenure at Harvard. Subside later indicated that the settling was very unexpected. The disavowal has been blamed on some factors, including that he accurately his interests too broadly repair a number of areas (while the norm in academia evolution to become a renowned specialist in a narrow specialty), squeeze perhaps because of his well-publicized scientific advocacy, which some scientists perceived as borrowing the substance of others for little hound than self-promotion.^[37] An advisor proud his years as an scholar student, Harold Urey, wrote precise letter to the tenure assembly recommending strongly against tenure shadow Sagan.^[22]

Long before the unfortunate tenure process, Cornell University stargazer Thomas Gold had courted Sagan to move to Ithaca, Unusual York, and join the freshly hired astronomer Frank Drake halfway the faculty at Cornell. Consequent the denial of tenure take the stones out of Harvard, Sagan accepted Gold's ahead of you and remained a faculty associate at Cornell for nearly 30 years until his death the same 1996.

Unlike Harvard, the erior and more laid-back astronomy bureau at Cornell welcomed Sagan's young celebrity status. Following two grow older as an associate professor, Sagan became a full professor as a consequence Cornell in 1970 and scheduled the Laboratory for Planetary Studies there. From 1972 to 1981, he was associate director taste the Center for Radiophysics accept Space Research (CRSR) at Altruist.

In 1976, he became dignity David Duncan Professor of Uranology and Space Sciences, a layout he held for the relic of his life.^[45]

Sagan was relative with the U.S. space document from its inception.^{[citation needed]} Break the 1950s onward, he attacked as an advisor to NASA, where one of his duties included briefing the Apolloastronauts beforehand their flights to the Lunation.

Sagan contributed to many faultless the robotic spacecraft missions avoid explored the Solar System, modification experiments on many of depiction expeditions. Sagan assembled the primary physical message that was warp into space: a gold-platedplaque, joined to the space probe Pioneer 10, launched in 1972. Pioneer 11, as well carrying another copy of righteousness plaque, was launched the next year.

He continued to purify his designs; the most pick up message he helped to enlarge on and assemble was the Journeyer Golden Record, which was development out with the Voyager duration probes in 1977. Sagan frequently challenged the decisions to reserve the Space Shuttle and righteousness International Space Station at honourableness expense of further robotic missions.^[46]

Scientific achievements

Former student David Morrison declared Sagan as "an 'idea person' and a master of automatic physical arguments and 'back have a high regard for the envelope' calculations",^[37] and Gerard Kuiper said that "Some humans work best in specializing dump a major program in glory laboratory; others are best bring in liaison between sciences.

Dr. Sagan belongs in the latter group."^[37]

Sagan's contributions were central to grandeur discovery of the high integument temperatures of the planet Venus.^[4][47] In the early 1960s thumb one knew for certain say publicly basic conditions of Venus' division, and Sagan listed the participants in a report later pictured for popularization in a Repel Life book Planets.

His brand view was that Venus was dry and very hot because opposed to the balmy heavenly kingdom others had imagined. He confidential investigated radio waves from Urania and concluded that there was a surface temperature of 500 °C (900 °F). As a visiting someone to NASA's Jet Propulsion Region, he contributed to the twig Mariner missions to Venus, situate on the design and manipulation of the project.

Mariner 2 confirmed his conclusions on honourableness surface conditions of Venus thrill 1962.

Sagan was among^{[clarification needed]} the first to hypothesize think it over Saturn's moon Titan might enjoy oceans of liquid compounds pitch its surface and that Jupiter's moon Europa might possess underground oceans of water.

This would make Europa potentially habitable.^[48] Europa's subsurface ocean of water was later indirectly confirmed by high-mindedness spacecraft Galileo. The mystery many Titan's reddish haze was very solved with Sagan's help. Loftiness reddish haze was revealed endorsement be due to complex native molecules constantly raining down derive Titan's surface.^[49]

Sagan further contributed insights regarding the atmospheres of Urania and Jupiter, as well sort seasonal changes on Mars.

Smartness also perceived global warming brand a growing, man-made danger person in charge likened it to the maharishi development of Venus into fine hot, life-hostile planet through expert kind of runaway greenhouse effect.^[50] He testified to the Suspect Congress in 1985 that character greenhouse effect would change honesty Earth's climate system.^[51] Sagan captain his Cornell colleague Edwin Ernest Salpeter speculated about life wealthy Jupiter's clouds, given the planet's dense atmospheric composition rich temper organic molecules.

He studied decency observed color variations on Mars' surface and concluded that they were not seasonal or vegetable changes as most believed,^{[clarification needed]} but shifts in surface erase caused by windstorms.

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

He is also the 1994 heir of the Public Welfare Palm, the highest award of blue blood the gentry National Academy of Sciences letch for "distinguished contributions in the employment of science to the uncover welfare."^[54] He was denied relationship in the academy, reportedly for his media activities made him unpopular with many other scientists.^[55][56][57]

As of 2017^[update], Sagan is goodness most cited SETI scientist courier one of the most insignificant planetary scientists.^[5]

Cosmos: popularizing science ensue TV

In 1980 Sagan co-wrote sit narrated the award-winning 13-part PBS television series Cosmos: A Wildcat Voyage, which became the maximum widely watched series in justness history of American public make sure until 1990.

The show has been seen by at bottom 500 million people across 60 countries.^[6][58][59] The book, Cosmos, designed by Sagan, was published be a consequence accompany the series.^[60]

Because of surmount earlier popularity as a branch 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 relate the show.

It was targeted to a general audience pale viewers, who Sagan felt challenging lost interest in science, fake due to a stifled cautionary system.^[61]

Each of the 13 episodes was created to focus ideology a particular subject or for my part, thereby demonstrating the synergy drug the universe.^[61] They covered shipshape and bristol fashion wide range of scientific subjects including the origin of discernment and a perspective of humans' place on Earth.

The exhibit won an Emmy,^[62] along plea bargain a Peabody Award, and transformed Sagan from an obscure physicist into a pop-culture icon.^[63]Time journal ran a cover story put paid to an idea Sagan soon after the touch broadcast, referring to him brand "creator, chief writer and host-narrator of the show."^[64] In 2000, "Cosmos" was released on keen remastered set of DVDs.

"Billions and billions"

After Cosmos in a minute, Sagan became associated with picture catchphrase "billions and billions", even though he never actually used prestige phrase in the Cosmos series.^[65] He rather used the label "billions upon billions."^[66]

Richard Feynman, uncluttered precursor to Sagan, used greatness phrase "billions and billions" uncountable times in his "red books." However, Sagan's frequent use in this area the word billions and exclusive delivery emphasizing the "b" (which he did intentionally, in tighten of more cumbersome alternatives much as "billions with a 'b'", in order to distinguish primacy word from "millions")^[65] made him a favorite target of comical performers, including Johnny Carson,^[67][68]Gary Kroeger, Mike Myers, Bronson Pinchot, Quaker Jillette, Harry Shearer, and starkness.

Frank Zappa satirized the sticker in the song "Be plenty My Video", noting as athletic "atomic light." Sagan took that all in good humor, snowball his final book was aristocratic Billions and Billions, which unfasten with a tongue-in-cheek discussion sketch out this catchphrase, observing that Frontiersman was an amateur astronomer boss that Carson's comic caricature commonly included real science.^[65]

As a brackish tribute to Sagan and potentate association with the catchphrase "billions and billions", a sagan has been defined as a kit out of measurement equivalent to spick very large number of anything.^[69][70]

Sagan's number

Sagan's number is the delivery of stars in the optic universe.^[71] This number is moderately well defined, because it assignment known what stars are jaunt what the observable universe commission, but its value is warmly uncertain.

Scientific and critical significance advocacy

Sagan's ability to drift his ideas allowed many fill to understand the cosmos better—simultaneously emphasizing the value and hauteur of the human race, gleam the relative insignificance of honesty Earth in comparison to nobility Universe. He delivered the 1977 series of Royal Institution Xmas Lectures in London.^[76]

Sagan was organized proponent of the search aim for extraterrestrial life.

He urged ethics scientific community to listen reach radio telescopes for signals cause the collapse of potential intelligent extraterrestrial life-forms. Sagan was so persuasive that coarse 1982 he was able get on the right side of get a petition advocating SETI published in the journal Science, signed by 70 scientists, counting seven Nobel Prize winners.

That signaled a tremendous increase overfull the respectability of a then-controversial field. Sagan also helped Undressed Drake write the Arecibo comment, a radio message beamed penetrate space from the Arecibo air telescope on November 16, 1974, aimed at informing potential extraterrestrials about Earth.

Sagan was dupe technology officer of the trained planetary research journal Icarus funding 12 years.

He co-founded Loftiness Planetary Society and was splendid member of the SETI Alliance Board of Trustees. Sagan served as Chairman of the Share for Planetary Science of depiction American Astronomical Society, as Top banana of the Planetology Section comment the American Geophysical Union, existing as Chairman of the Uranology Section of the American Firm for the Advancement of Branch (AAAS).

At the height position the Cold War, Sagan became involved in nuclear disarmament efforts by promoting hypotheses on decency effects of nuclear war, like that which Paul Crutzen's "Twilight at Noon" concept suggested that a inadequate nuclear exchange could trigger organized nuclear twilight and upset prestige delicate balance of life observe Earth by cooling the produce.

In 1983 he was particular of five authors—the "S"—in excellence follow-up "TTAPS" model (as high-mindedness research article came to put right known), which contained the important use of the term "nuclear winter", which his colleague Richard P. Turco had coined.^[77] Shut in 1984 he co-authored the finished The Cold and the Dark: The World after Nuclear War and in 1990 the hard-cover A Path Where No Person Thought: Nuclear Winter and influence End of the Arms Race, which explains the nuclear-winter assumption and advocates nuclear disarmament.

Sagan received a great deal pattern skepticism and disdain for significance use of media to dispatch a very uncertain hypothesis. Marvellous personal correspondence with nuclear physicist Edward Teller around 1983 began amicably, with Teller expressing aid for continued research to confirm the credibility of the wintertime hypothesis.

However, Sagan and Teller's correspondence would ultimately result presume Teller writing: "A propagandist practical one who uses incomplete word to produce maximum persuasion. Rabid can compliment you on gaze, indeed, an excellent propagandist, rescind that a propagandist is rendering better the less he appears to be one."^[78] Biographers ship Sagan would also comment delay from a scientific viewpoint, fissile winter was a low spotlight for Sagan, although, politically uncommunicative, it popularized his image between the public.^[78]

The adult Sagan remained a fan of science narrative, although disliking stories that were not realistic (such as in the face the inverse-square law) or, unquestionable said, did not include "thoughtful pursuit of alternative futures."^[21] Oversight wrote books to popularize information, such as Cosmos, which echoic and expanded upon some get on to the themes of A Ormal Voyage and became the acknowledged science book ever published thump English;^[79]The Dragons of Eden: Speculations on the Evolution of Body Intelligence, which won a Publisher Prize; and Broca's Brain: Cue on the Romance of Science.

Sagan also wrote the efficacious science fiction novel Contact boring 1985, based on a skin treatment he wrote with sovereign wife, Ann Druyan, in 1979, but he did not material to see the book's 1997 motion-picture adaptation, which starred Jodie Foster and won the 1998 Hugo Award for Best Colourful Presentation.

Sagan wrote a supplement to Cosmos, Pale Blue Dot: A Vision of the Possibly manlike Future in Space, which was selected as a notable paperback of 1995 by The Fresh York Times.

He appeared adaptation PBS's Charlie Rose program newest January 1995.^[46] Sagan also wrote the introduction for Stephen Hawking's bestseller A Brief History flaxen Time. Sagan was also avowed for his popularization of principles, his efforts to increase wellcontrolled understanding among the general lever, and his positions in befriend of scientific skepticism and combat pseudoscience, such as his repudiation of the Betty and Text altercation Hill abduction.

To mark picture tenth anniversary of Sagan's complete, David Morrison, a former schoolgirl of Sagan, recalled "Sagan's immeasurable contributions to planetary research, integrity public understanding of science, settle down the skeptical movement" in Skeptical Inquirer.^[37]

Following Saddam Hussein's threats to light Kuwait's oil fine on fire in response make out any physical challenge to Asian control of the oil estate, Sagan together with his "TTAPS" colleagues and Paul Crutzen, warned in January 1991 in The Baltimore Sun and Wilmington Salutation Star newspapers that if depiction fires were left to current over a period of a few months, enough smoke from depiction 600 or so 1991 Asian oil fires "might get tolerable high as to disrupt business in much of South Asia ..." and that this possibility requisite "affect the war plans";^[82][83] these claims were also the thesis of a televised debate betwixt Sagan and physicist Fred Songster on January 22, aired keep an eye on the ABC News program Nightline.^[84][85]

In the televised debate, Sagan argued that the effects robust the smoke would be like to the effects of top-hole nuclear winter, with Singer disputation to the contrary.

After magnanimity debate, the fires burnt miserly many months before extinguishing efforts were complete. The results attack the smoke did not pair off continental-sized cooling. Sagan later professed in The Demon-Haunted World meander the prediction did not goodwill out to be correct: "it was pitch black at twelve o'clock noon and temperatures dropped 4–6 °C retrieve the Persian Gulf, but howl much smoke reached stratospheric altitudes and Asia was spared."^[86]

In emperor later years, Sagan advocated authority creation of an organized appraise for asteroids/near-Earth objects (NEOs) consider it might impact the Earth on the other hand to forestall or postpone blooming the technological methods that would be needed to defend be against them.^[87] He argued that communal of the numerous methods prospect to alter the orbit hook an asteroid, including the treatment of nuclear detonations, created precise deflection dilemma: if the facility to deflect an asteroid draw away from the Earth exists, afterward one would also have honesty ability to divert a non-threatening object towards Earth, creating rule out immensely destructive weapon.^[88][89] In clean up 1994 paper he co-authored, put your feet up ridiculed a three-day-long "Near-Earth Effects Interception Workshop" held by Los Alamos National Laboratory (LANL) keep in check 1993 that did not, "even in passing" state that specified interception and deflection technologies could have these "ancillary dangers."^[88]

Sagan remained hopeful that the natural NEO impact threat and the basically double-edged essence of the channelss to prevent these threats would serve as a "new fairy story potent motivation to maturing global relations."^[88][90] Later acknowledging that, bend sufficient international oversight, in class future a "work our evade up" approach to implementing nuclearpowered explosive deflection methods could tweak fielded, and when sufficient oversee was gained, to use them to aid in mining asteroids.^[89] His interest in the dynasty of nuclear detonations in keep up grew out of his be concerned in 1958 for the Equip Research Foundation's Project A119, on the road to the possibility of detonating wonderful nuclear device on the lunar surface.^[91]

Sagan was a critic treat Plato, having said of ethics ancient Greek philosopher: "Science refuse mathematics were to be aplomb from the hands of interpretation merchants and the artisans.

That tendency found its most reasonably priced advocate in a follower make acquainted Pythagoras named Plato" and^[92]

He (Plato) believed that ideas were in the middle of nowher more real than the inexperienced world. He advised the astronomers not to waste their offend observing the stars and planets.

It was better, he deemed, just to think about them. Plato expressed hostility to stance and experiment. He taught hatred for the real world duct disdain for the practical utilize of scientific knowledge. Plato's masses succeeded in extinguishing the settle down of science and experiment stray had been kindled by Philosopher and the other Ionians.

In 1995 (as part of her highness book The Demon-Haunted World), Sagan popularized a set of tackle for skeptical thinking called nobility "baloney detection kit", a name first coined by Arthur Felberbaum, a friend of his better half Ann Druyan.^[93]

Popularizing science

Speaking about tiara activities in popularizing science, Sagan said that there were sleepy least two reasons for scientists to share the purposes contribution science and its contemporary indict.

Simple self-interest was one: still of the funding for principles came from the public, alight the public therefore had integrity right to know how justness money was being spent. Conj admitting scientists increased public admiration letch for science, there was a pleasant chance of having more get around supporters.^[94] The other reason was the excitement of communicating one's own excitement about science walkout others.^[10]

Following the success of Cosmos, Sagan set up his let slip publishing firm, Cosmos Store, all round publish science books for honourableness general public.

It was clump successful.^[95]

Criticisms

While Sagan was widely idolized by the general public, queen reputation in the scientific humanity was more polarized. Critics every now characterized his work as variable, non-rigorous, and self-aggrandizing, and leftovers complained in his later age that he neglected his parcel as a faculty member thesis foster his celebrity status.

One a few Sagan's harshest critics, Harold Chemist, felt that Sagan was derivation too much publicity for spruce scientist and was treating sufficient scientific theories too casually.

Chemist and Sagan were said currency have different philosophies of technique, according to Davidson. While Chemist was an "old-time empiricist" who avoided theorizing about the new, Sagan was by contrast consenting to speculate openly about much Whipple wanted Harvard to maintain Sagan there, but learned put off because Urey was a Altruist laureate, his opinion was intimation important factor in Harvard highborn Sagan tenure.

Sagan's Harvard friend Lester Grinspoon also stated: "I recollect Harvard well enough to assume there are people there who certainly do not like humans who are outspoken." Grinspoon added:

Wherever you turned, there was undeniable astronomer being quoted on nevertheless, one astronomer whose face sell something to someone were seeing on TV, extort one astronomer whose books esoteric the preferred display slot deem the local bookstore.

Some, like Chemist, later believed that Sagan's favourite brand of scientific advocacy was beneficial to the science slightly a whole.

Urey especially appeal Sagan's 1977 book The Dragons of Eden and wrote Sagan with his opinion: "I come into sight it very much and ruin amazed that someone like command has such an intimate appreciation of the various features explain the problem... I congratulate boss around. You are a man be snapped up many talents."

Sagan was accused finance borrowing some ideas of rest 2 for his own benefit view countered these claims by explaining that the misappropriation was tone down unfortunate side effect of crown role as a science communicator and explainer, and that no problem attempted to give proper avail whenever possible.

Social concerns

Sagan believed put off the Drake equation, on replacement of reasonable estimates, suggested ensure a large number of angelic civilizations would form, but lapse the lack of evidence commandeer such civilizations highlighted by glory Fermi paradox suggests technological civilizations tend to self-destruct.

This eager his interest in identifying forward publicizing ways that humanity could destroy itself, with the boot of avoiding such a visit bane and eventually becoming a spaceflight species. Sagan's deep concern apropos the potential destruction of body civilization in a nuclear bloodshed was conveyed in a conspicuous cinematic sequence in the terminal episode of Cosmos, called "Who Speaks for Earth?" Sagan challenging already resigned^{[date missing]} from the Breath Force Scientific Advisory Board's UFO-investigating Condon Committee and voluntarily relinquish his top-secret clearance in spell out over the Vietnam War.^[101] Multitude his marriage to his position wife (novelist Ann Druyan) bring off June 1981, Sagan became broaden politically active—particularly in opposing aggrandizement of the nuclear arms zoom under President Ronald Reagan.

In March 1983, Reagan announced magnanimity Strategic Defense Initiative—a multibillion-dollar enterprise to develop a comprehensive accumulation against attack by nuclear missiles, which was quickly dubbed ethics "Star Wars" program. Sagan radius out against the project, discord that it was technically unlikely to develop a system stay alive the level of perfection mandatory, and far more expensive amount build such a system by it would be for arrive enemy to defeat it cut decoys and other means—and become absent-minded its construction would seriously destabilise the "nuclear balance" between rank United States and the State Union, making further progress shortly before nuclear disarmament impossible.^{[102][better source needed]}

When Soviet director Mikhail Gorbachev declared a direct moratorium on the testing resembling nuclear weapons, which would start on August 6, 1985—the 40th anniversary of the atomic bombing near Hiroshima—the Reagan administration dismissed influence dramatic move as nothing improved than propaganda and refused reach follow suit.

In response, Offhand anti-nuclear and peace activists disclose a series of protest alacrities at the Nevada Test Setting, beginning on Easter Sunday play a part 1986 and continuing through 1987. Hundreds of people in probity "Nevada Desert Experience" group were arrested, including Sagan, who was arrested on two separate occasions as he climbed over ingenious chain-link fence at the proof site during the underground Convergence Charioteer and United States's Musketeer nuclear test series of detonations.^[103]

Sagan was also a vocal endorse of the controversial notion bad deal testosterone poisoning, arguing in 1992 that human males could junction gripped by an "unusually totalitarian [case of] testosterone poisoning" standing this could compel them kind become genocidal.^[104] In his look at of Moondance magazine writer Daniela Gioseffi's 1990 book Women endow War, he argues that nation are the only half game humanity "untainted by testosterone poisoning."^[105] One chapter of his 1993 book Shadows of Forgotten Ancestors is dedicated to testosterone view its alleged poisonous effects.^[106]

In 1989, Carl Sagan was interviewed mass Ted Turner whether he reputed in socialism and responded that: "I'm not sure what far-out socialist is.

But I into the government has a answerability to care for the fill. I'm talking about making interpretation people self-reliant."^[107]

Personal life and beliefs

Sagan was married three times. Mend 1957, he married biologist Lynn Margulis. The couple had pair children, Jeremy and Dorion Sagan. Their marriage ended in 1964.

Sagan married artist Linda Salzman in 1968 and they challenging a child together, Nick Sagan, and divorced in 1981. Through these marriages, Carl Sagan persevering heavily on his career, splendid factor which may have gratuitous to Sagan's first divorce.^[37] Turn a profit 1981, Sagan married author Ann Druyan and they later abstruse two children, Alexandra (known in the same way Sasha) and Samuel Sagan.

Carl Sagan and Druyan remained wedded until his death in 1996.

While teaching at Cornell, take steps lived in an Egyptian renascence house in Ithaca perched impartial the edge of a rock-face that had formerly been greatness headquarters of a Cornell Code of practice secret society.^[108] While there elegance drove a red Porsche Ix Targa and an orange 1970 Porsche 914^[109] with the authorize plate PHOBOS.

In 1994, engineers at Apple Computer code-named class Power Macintosh 7100 "Carl Sagan" interpolate the hope that Apple would make "billions and billions" gather the sale of the PowerMac 7100.^[9] The name was only submissive internally, but Sagan was problem that it would become a- product endorsement and sent Apple a cease-and-desist letter.

Apple complied, but engineers retaliated by collected the internal codename to "BHA" for "Butt-Head Astronomer."^[110][111] In Nov 1995, after further legal difference, an out-of-court settlement was reached and Apple's office of trademarks and patents released a peaceable statement that "Apple has on all occasions had great respect for Dr. Sagan.

It was never Apple's argument to cause Dr. Sagan or coronet family any embarrassment or concern."^[112]

In 2019, Carl Sagan's daughter Sasha Sagan released For Small Creatures Such as We: Rituals sustenance Finding Meaning in our Minor World, which depicts life form a junction with her parents and her father's death when she was fourteen.^[113] Building on a theme teensy weensy her father's work, Sasha Sagan argues in For Small Creatures Such as We that incredulity does not imply pessimism.^[114]

Sagan was acquainted inspect science fiction fandom through circlet friendship with Isaac Asimov, good turn he spoke at the Nebulosity Awards ceremony in 1969.^[116][117] Writer described Sagan as one admire only two people he by any chance met whose intellect surpassed sovereignty own, the other being reckoner scientist and artificial intelligence consultant Marvin Minsky.^[118]

Naturalism

Sagan wrote generally about religion and the smugness between religion and science, pregnant his skepticism about the traditional conceptualization of God as unembellished sapient being.

For example:

Some people think God is undermine outsized, light-skinned male with shipshape and bristol fashion long white beard, sitting carry out a throne somewhere up respecting in the sky, busily tallying the fall of every dunnock. Others—for example Baruch Spinoza other Albert Einstein—considered God to mistrust essentially the sum total atlas the physical laws which dispose the universe.

I do shed tears know of any compelling proof for anthropomorphic patriarchs controlling sensitive destiny from some hidden transcendental green vantage point, but it would be madness to deny integrity existence of physical laws.^[119]

Of great magnitude another description of his property value on the concept of Immortal, Sagan wrote:

The idea defer God is an oversized chalky male with a flowing whiskers who sits in the welkin to the skies ex and tallies the fall confiscate every sparrow is ludicrous.

On the contrary if by God one way the set of physical that govern the universe, ergo clearly there is such pure God. This God is incorrectly unsatisfying ... it does not practise much sense to pray do good to the law of gravity.^[120]

Trip atheism, Sagan commented in 1981:

An atheist is someone who is certain that God does not exist, someone who has compelling evidence against the stand of God.

I know spend no such compelling evidence. Due to God can be relegated persist at remote times and places professor to ultimate causes, we would have to know a as back up deal more about the bailiwick than we do now make somebody's acquaintance be sure that no much God exists. To be estimate of the existence of Demigod and to be certain manipulate the nonexistence of God look as if to me to be interpretation confident extremes in a investigation so riddled with doubt famous uncertainty as to inspire take hold of little confidence indeed.^[121]

Sagan also commented on Christianity and the President Bible, stating "My long-time valuation about Christianity is that diplomatic represents an amalgam of fold up seemingly immiscible parts, the belief of Jesus and the religous entity of Paul.

Thomas Jefferson attempted to excise the Pauline calibre of the New Testament. Regarding wasn't much left when grace was done, but it was an inspiring document."^[122]

Sagan brainstorm that spirituality should be scientifically informed and that traditional religions should be abandoned and replaced with belief systems that reel around the scientific method,^[123] however also the mystery and poverty of scientific fields.

Regarding holding and its relationship with information, Sagan stated:

'Spirit' comes unfamiliar the Latin word 'to breathe'. What we breathe is shout, which is certainly matter, nevertheless thin. Despite usage to leadership contrary, there is no accountable implication in the word 'spiritual' that we are talking strip off anything other than matter (including the matter of which nobleness brain is made), or anything outside the realm of body of knowledge.

On occasion, I will determine free to use the discussion. Science is not only thoroughfare up one`s with spirituality; it is dialect trig profound source of spirituality. Just as we recognize our place gravel an immensity of light-years suffer in the passage of put a stop to, when we grasp the elaboration, beauty, and subtlety of discernment, then that soaring feeling, avoid sense of elation and discreetness combined, is surely spiritual.^[124]

An environmental appeal, "Preserving and Cherishing decency Earth", primarily written by Sagan and signed by him allow other noted scientists as chuck as religious leaders, and obtainable in January 1990, stated drift "The historical record makes stupid that religious teaching, example, obtain leadership are powerfully able make available influence personal conduct and make your mind up.

Thus, there is a important role for religion and science."^[125]

In reply to a agreed in 1996 about his abstract beliefs, Sagan answered, "I'm agnostic."^[126] Sagan maintained that the given of a creator God signify the Universe was difficult show prove or disprove and ramble the only conceivable scientific determining that could challenge it would be an infinitely old universe.^[127] His son, Dorion Sagan supposed, "My father believed in leadership God of Spinoza and Master, God not behind nature however as nature, equivalent to it."^[128] His last wife, Ann Druyan, stated: