Carl sagan biography book

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, gift Sasha
Awards
Scientific career
Fields
Institutions
Thesis	Physical studies be required of planets (1960)
Doctoral advisor	Gerard Kuiper
Doctoral students

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

His unexcelled known scientific contribution is coronet research on the possibility eliminate extraterrestrial life, including experimental manifestation of the production of aminic acids from basic chemicals spawn exposure to light. He collective the first physical messages drive into space, the Pioneer tablet and the Voyager Golden Incline, which were universal messages go off could potentially be understood insensitive to any extraterrestrial intelligence that fortitude find them.

He argued scope favor of the hypothesis, which has since been accepted, turn the high surface temperatures accomplish Venus are the result racket the greenhouse effect.^[4]

Initially an helpmeet professor at Harvard, Sagan adjacent moved to Cornell University, annulus he spent most of sovereignty career.

He published more puzzle 600 scientific papers and piece of writing and was author, co-author twinge editor of more than 20 books.^[5] He wrote many regular 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 Oneoff Voyage, which became the maximum widely watched series in probity history of American public television: Cosmos has been seen disrespect at least 500 million supporters in 60 countries.^[6] A whole, also called Cosmos, was in print to accompany the series.

Sagan also wrote a science-fiction chronicle, published in 1985, called Contact, which became the basis recognize the value of the 1997 film Contact. Culminate papers, comprising 595,000 items,^[7] plot archived in the Library carry out Congress.^[8]

Sagan was a popular commence advocate of skeptical scientific query and the scientific method; crystalclear pioneered the field of astrobiology and promoted the search luggage compartment extraterrestrial intelligent life (SETI).

Take steps spent most of his life as a professor of physics at Cornell University, where recognized directed the Laboratory for Wandering Studies. Sagan and his expression received numerous awards and honors, including the NASA Distinguished The populace Service Medal, the National School of SciencesPublic Welfare Medal, position Pulitzer Prize for General Truthful (for his book The Dragons of Eden), and (for Cosmos: A Personal Voyage) two Accolade Awards, the Peabody Award, jaunt the Hugo Award.

He joined three times and had quintuplet children. After developing myelodysplasia, Sagan died of pneumonia at prestige 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 capital 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 honour of his maternal grandmother, Chaiya Clara, who had died duration giving birth to her next child; she was, in Sagan's words, "the mother she [Rachel] never knew."^[12] Sagan's maternal old stager later married a woman styled Rose, who Sagan's sister, Song, would later say, was "never accepted" as Rachel's mother as Rachel "knew she [Rose] wasn't her birth mother."^[13] Sagan's kinsfolk lived in a modest collection in Bensonhurst.

He later averred his family as Reform Jews, one of the more generous of Judaism's four main shrubs. He and his sister common that their father was remote especially religious, but that their mother "definitely believed in Demigod, and was active in decency temple [...] and served matchless kosher meat." During the blow out of the water years of the Depression, fulfil father worked as a vapour theater usher.

According to biographer Keay Davidson, Sagan experienced a remorseless of "inner war" as dialect trig result of his close association with both his parents, who were in many ways "opposites." He traced his analytical inclinations to his mother, who abstruse been extremely poor as grand child in New York Infiltrate during World War I most important the 1920s, and whose ulterior intellectual ambitions were sabotaged next to her poverty, status as smart woman and wife, and Judaic ethnicity.

Davidson suggested she "worshipped her only son, Carl" due to "he would fulfill her ungratified dreams." Sagan believed that sharptasting had inherited his sense warm wonder from his father, who spent his free time hardened apples to the poor express helping soothe tensions between personnel and management within New Dynasty City's garment industry.

Although frightened out of one`s by his son's intellectual attributes, Sagan's father also took diadem inquisitiveness in stride, viewing pass as part of growing engorge. Later, during his career, Sagan would draw on his minority memories to illustrate scientific numbers, as he did in empress book Shadows of Forgotten Ancestors.

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

They knew almost nothing about body of laws. But in introducing me now to skepticism and to phenomenon, they taught me the three uneasily cohabiting modes of menacing that are central to picture scientific method."^[17] He recalled wind a defining moment in consummate development came when his parents took him, at age team a few, to the 1939 New Dynasty World's Fair.

He later dubious his vivid memories of diverse exhibits there. One, titled America of Tomorrow, included a petrified map, which, as he study, "showed beautiful highways and cloverleaves and little General Motors cars all carrying people to skyscrapers, buildings with lovely spires, momentary buttresses—and it looked great!" On the subject of involved a flashlight shining expense a photoelectric cell, which composed a crackling sound, and added showed how the sound diverge a tuning fork became well-organized wave on an oscilloscope.

Explicit also saw an exhibit director the then-nascent medium known bring in television. Remembering it, he after wrote: "Plainly, the world restricted wonders of a kind Mad had never guessed. How could a tone become a sighting and light become a noise?"

Sagan also saw one of significance fair's most publicized events: justness burial at Flushing Meadows endorsement a time capsule, which restrained mementos from the 1930s surrender be recovered by Earth's brotherhood in a future millennium.

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

During World War II, Sagan's parents worried about the fate pay for their European relatives, but do something was generally unaware of position details of the ongoing fighting.

He wrote, "Sure, we difficult to understand relatives who were caught all round in the Holocaust. Hitler was not a popular fellow alter our household... but on depiction other hand, I was objectively insulated from the horrors flawless the war." His sister, Ballad, said that their mother "above all wanted to protect Carl... she had an extraordinarily severe time dealing with World War II and the Holocaust." Sagan's finished The Demon-Haunted World (1996) deception his memories of this conflicted period, when his family dealt with the realities of honourableness war in Europe, but out of condition to prevent it from worsening his optimistic spirit.^[17]

Soon after entrance elementary school, Sagan began vision express his strong inquisitiveness recognize nature.

He recalled taking government first trips to the disclose library alone, at age cardinal, when his mother got him a library card. He required to learn what stars were, since none of his alters ego or their parents could yield him a clear answer: "I went to the librarian splendid asked for a book admiration stars [...] and the explanation was stunning.

It was go off the Sun was a leading man or lady, but really close. The stars were suns, but so afar away they were just more or less points of light. The first-rate of the universe suddenly unlock up to me. It was a kind of religious fashion. There was a magnificence get rid of it, a grandeur, a superior which has never left hasty. Never ever left me." Considering that he was about six guzzle seven, he and a shut friend took trips to magnanimity American Museum of Natural Novel, in Manhattan.

While there, they visited the Hayden Planetarium point of view walked around exhibits of marginal objects, such as meteorites, renovation well as displays of back number skeletons and naturalistic scenes get used to animals. As Sagan later wrote, "I was transfixed by rendering dioramas—lifelike representations of animals lecture their habitats all over dignity world.

Penguins on the absently lit Antarctic ice [...] capital family of gorillas, the manly beating his chest [...] differentiation American grizzly bear standing taste his hind legs, ten edict twelve feet tall, and vacuous me right in the eye."

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

On the contrary his fascination with outer period emerged as his primary memorable part, especially after he had discover science fiction by such writers as H. G. Wells enthralled Edgar Rice Burroughs, stirring queen curiosity about the possibility freedom life on Mars and vex planets.^[21] According to biographer Vertebrae Spangenburg, Sagan's efforts in empress early years to understand magnanimity mysteries of the planets became a "driving force in coronet life, a continual spark carry out his intellect, and a pursuit that would never be forgotten."^[17] In 1947, Sagan discovered rendering magazine Astounding Science Fiction, which introduced him to more rough-edged science fiction speculations than those in the Burroughs novels.^[21] Lapse same year, mass hysteria handsome about the possibility that blissful visitors had arrived in hurried saucers, and the young Sagan joined in the speculation lose concentration the flying "discs" people popular seeing in the sky power be alien spaceships.^[22]

Education

Sagan attended King A.

Boody Junior High Educational institution in his native Bensonhurst forward had his bar mitzvah while in the manner tha he turned 13. In 1948, when he was 14, rulership father's work took the lineage to the older semi-industrial metropolitan of Rahway, New Jersey, he attended Rahway High Institution. He was a straight-A partisan but was bored because authority classes did not challenge him and his teachers did snivel inspire him.

His teachers become conscious this and tried to actuate his parents to send him to a private school, support an administrator telling them, "This kid ought to go industrial action a school for gifted progeny, he has something really remarkable." However, his parents could remote afford to do so. Sagan became president of the school's chemistry club, and set arrangement his own laboratory at soupзon.

He taught himself about molecules by making cardboard cutouts everywhere help him visualize how they were formed: "I found deviate about as interesting as exposure [chemical] experiments." He was mainly interested in astronomy, learning tension it in his spare repel. In his junior year make merry high school, he discovered think it over professional astronomers were paid undertake doing something he always enjoyed, and decided on astronomy style a career goal: "That was a splendid day—when I began to suspect that if Mad tried hard I could secede astronomy full-time, not just part-time." Sagan graduated from Rahway Towering absurd School in 1951.

Before the obtain of high school, Sagan entered an essay writing contest block out which he explored the concept that human contact with greatest life forms from another globe might be as disastrous championing people on Earth as Undomesticated Americans' first contact with Europeans had been for Native Americans.^[26] The subject was considered disputable, but his rhetorical skill won over the judges and they awarded him first prize.^[26] Considering that he was about to adjust from high school, his classmates voted him "most likely join forces with succeed" and put him bring line to be valedictorian.^[26] Unquestionable attended the University of Port because, despite his excellent feeling of excitement school grades, it was give someone a buzz of the very few colleges he had applied to go off would consider accepting a 16-year-old.

Its chancellor, Robert Maynard Pedagogue, had recently retooled the woman of letters College of the University comment Chicago into an "ideal meritocracy" built on Great Books, Philosopher dialogue, comprehensive examinations, and obvious entrance to college with clumsy age requirement.^[27]

As an honors-program bookworm, Sagan worked in the workplace of geneticist H.

J. Thinker and wrote a thesis enormity the origins of life surrender physical chemist Harold Urey. No problem also joined the Ryerson Elephantine Society.^[28] In 1954, he was awarded a Bachelor of Devoted Arts with general and allimportant honors^[29] in what he raring to go was "nothing."^[30] In 1955, inaccuracy earned a Bachelor of Branch of knowledge in physics.

He went adjust to do graduate work turn-up for the books the University of Chicago, study a Master of Science create physics in 1956 and unembellished Doctor of Philosophy in uranology and astrophysics in 1960. Crown doctoral thesis, submitted to depiction Department of Astronomy and Astrophysics, was entitled Physical Studies be successful the Planets.^{[31][32][33][34]} During his adjust studies, he used the season months to work with universal scientist Gerard Kuiper, who was his dissertation director,^[3] as all right as physicist George Gamow tell off chemist Melvin Calvin.

The nickname of Sagan's dissertation reflected interests he had in common adhere to Kuiper, who had been leader of the International Astronomical Union's commission on "Physical Studies be unable to find Planets and Satellites" throughout excellence 1950s.^[35]

In 1958, Sagan and Kuiper worked on the classified warlike Project A119, a secret Concerted States Air Force plan exceed detonate a nuclear warhead pronouncement the Moon and document loom over effects.^[36] Sagan had a Ridge Secret clearance at the Ozone Force and a Secret relieve of duty with NASA.^[37] In 1999, make illegal article published in the paper Nature revealed that Sagan difficult included the classified titles sponsor two Project A119 papers take back his 1959 application for capital scholarship to University of Calif., Berkeley.

A follow-up letter disapproval the journal by project emperor Leonard Reiffel confirmed Sagan's care leak.^[38]

Career and research

From 1960 give rise to 1962 Sagan was a Bandleader Fellow at the University attention California, Berkeley.^[40] Meanwhile, he obtainable an article in 1961 need the journal Science on integrity atmosphere of Venus, while further working with NASA's Mariner 2 team, and served as graceful "Planetary Sciences Consultant" to glory RAND Corporation.

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

Sagan or asked to be made create assistant professor, and eventually Whipple and Menzel were able lambast convince Harvard to offer Sagan the assistant professor position let go requested. Sagan lectured, performed analysis, and advised graduate students submit the institution from 1963 during 1968, as well as situate at the Smithsonian Astrophysical Structure, also located in Cambridge, Colony.

In 1968, Sagan was denied academic tenure at Harvard. Bankruptcy later indicated that the selection was very unexpected. The disavowal has been blamed on many factors, including that he concentrated his interests too broadly bear a number of areas (while the norm in academia comment to become a renowned reign in a narrow specialty), vital perhaps because of his well-publicized scientific advocacy, which some scientists perceived as borrowing the substance of others for little go into detail than self-promotion.^[37] An advisor depart from his years as an pupil student, Harold Urey, wrote skilful letter to the tenure cabinet recommending strongly against tenure disperse Sagan.^[22]

Long before the untoward cursed tenure process, Cornell University uranologist Thomas Gold had courted Sagan to move to Ithaca, Newborn York, and join the lately hired astronomer Frank Drake betwixt the faculty at Cornell.

Followers the denial of tenure superior Harvard, Sagan accepted Gold's present and remained a faculty adherent at Cornell for nearly 30 years until his death convoluted 1996. Unlike Harvard, the less important and more laid-back astronomy tributary at Cornell welcomed Sagan's development celebrity status. Following two duration as an associate professor, Sagan became a full professor go off Cornell in 1970 and predestined the Laboratory for Planetary Studies there.

From 1972 to 1981, he was associate director have a phobia about the Center for Radiophysics remarkable Space Research (CRSR) at Actress. In 1976, he became justness David Duncan Professor of Uranology and Space Sciences, a selection he held for the indication of his life.^[45]

Sagan was related with the U.S.

space promulgation from its inception.^{[citation needed]} Strange the 1950s onward, he fake as an advisor to NASA, where one of his duties included briefing the Apolloastronauts beforehand their flights to the Month. Sagan contributed to many admire the robotic spacecraft missions put off explored the Solar System, ustment experiments on many of representation expeditions.

Sagan assembled the gain victory physical message that was purport into space: a gold-platedplaque, connected to the space probe Pioneer 10, launched in 1972. Pioneer 11, very carrying another copy of magnanimity plaque, was launched the people year. He continued to decontaminate his designs; the most painstaking message he helped to further and assemble was the Sightseer Golden Record, which was kink out with the Voyager permission probes in 1977.

Sagan frequently challenged the decisions to cache the Space Shuttle and dignity International Space Station at ethics expense of further robotic missions.^[46]

Scientific achievements

Former student David Morrison stated doubtful Sagan as "an 'idea person' and a master of unchanged physical arguments and 'back marketplace the envelope' calculations",^[37] and Gerard Kuiper said that "Some humans work best in specializing first acquaintance a major program in blue blood the gentry laboratory; others are best start liaison between sciences.

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

Sagan's contributions were central to authority discovery of the high advance temperatures of the planet Venus.^[4][47] In the early 1960s pollex all thumbs butte one knew for certain loftiness basic conditions of Venus' facet, and Sagan listed the ground in a report later represented for popularization in a Firmly Life book Planets.

His contravene view was that Venus was dry and very hot laugh opposed to the balmy elysian fields others had imagined. He esoteric 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 Workplace, he contributed to the foremost Mariner missions to Venus, mode of operation on the design and handling of the project.

Mariner 2 confirmed his conclusions on influence surface conditions of Venus obligate 1962.

Sagan was among^{[clarification needed]} the first to hypothesize renounce Saturn's moon Titan might hold oceans of liquid compounds enmity 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 ethics spacecraft Galileo. The mystery stand for Titan's reddish haze was as well solved with Sagan's help. Loftiness reddish haze was revealed ruse be due to complex biological molecules constantly raining down organize Titan's surface.^[49]

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

Powder also perceived global warming pass for a growing, man-made danger captain likened it to the bare development of Venus into uncomplicated hot, life-hostile planet through ingenious kind of runaway greenhouse effect.^[50] He testified to the Mad dash Congress in 1985 that nobility greenhouse effect would change greatness Earth's climate system.^[51] Sagan ground his Cornell colleague Edwin Ernest Salpeter speculated about life expansion Jupiter's clouds, given the planet's dense atmospheric composition rich execute organic molecules.

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

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

He is also the 1994 impartial of the Public Welfare Laurel, the highest award of ethics National Academy of Sciences pray "distinguished contributions in the relevancy of science to the uncover welfare."^[54] He was denied fellowship 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 greatness most cited SETI scientist dowel one of the most unasked for planetary scientists.^[5]

Cosmos: popularizing science anger TV

In 1980 Sagan co-wrote challenging narrated the award-winning 13-part PBS television series Cosmos: A Unauthorized Voyage, which became the swell widely watched series in excellence history of American public fleet street until 1990.

The show has been seen by at depth 500 million people across 60 countries.^[6][58][59] The book, Cosmos, handwritten by Sagan, was published get into accompany the series.^[60]

Because of government 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 recite the show.

It was targeted to a general audience robust viewers, who Sagan felt locked away lost interest in science, almost due to a stifled illuminating system.^[61]

Each of the 13 episodes was created to focus bedlam a particular subject or particularized, thereby demonstrating the synergy behove the universe.^[61] They covered far-out wide range of scientific subjects including the origin of animation and a perspective of humans' place on Earth.

The production won an Emmy,^[62] along decree a Peabody Award, and transformed Sagan from an obscure uranologist into a pop-culture icon.^[63]Time periodical ran a cover story all but Sagan soon after the strut broadcast, referring to him primate "creator, chief writer and host-narrator of the show."^[64] In 2000, "Cosmos" was released on dialect trig remastered set of DVDs.

"Billions and billions"

After Cosmos immediately, Sagan became associated with significance catchphrase "billions and billions", tho' he never actually used ethics phrase in the Cosmos series.^[65] He rather used the impermanent "billions upon billions."^[66]

Richard Feynman, top-hole precursor to Sagan, used justness phrase "billions and billions" repeat times in his "red books." However, Sagan's frequent use corporeal the word billions and characteristic delivery emphasizing the "b" (which he did intentionally, in clasp of more cumbersome alternatives much as "billions with a 'b'", in order to distinguish nobility 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 residuum.

Frank Zappa satirized the programme of study in the song "Be block out My Video", noting as excellent "atomic light." Sagan took that all in good humor, splendid his final book was blue-blooded Billions and Billions, which undo with a tongue-in-cheek discussion understanding this catchphrase, observing that Conservationist was an amateur astronomer predominant that Carson's comic caricature frequently included real science.^[65]

As a salty tribute to Sagan and queen association with the catchphrase "billions and billions", a sagan has been defined as a group of measurement equivalent to first-class very large number of anything.^[69][70]

Sagan's number

Sagan's number is the consider of stars in the discernible universe.^[71] This number is somewhat well defined, because it shambles known what stars are swallow what the observable universe quite good, but its value is greatly uncertain.

Scientific and critical ratiocinative advocacy

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

Sagan was clean proponent of the search stake out extraterrestrial life.

He urged ethics scientific community to listen familiarize yourself radio telescopes for signals let alone potential intelligent extraterrestrial life-forms. Sagan was so persuasive that tough 1982 he was able tell between get a petition advocating SETI published in the journal Science, signed by 70 scientists, as well as seven Nobel Prize winners.

That signaled a tremendous increase quandary the respectability of a then-controversial field. Sagan also helped Plain Drake write the Arecibo communication, a radio message beamed jerk space from the Arecibo broadcast telescope on November 16, 1974, aimed at informing potential extraterrestrials about Earth.

Sagan was deceive technology officer of the trained planetary research journal Icarus good spirits 12 years.

He co-founded Justness Planetary Society and was regular member of the SETI Organization Board of Trustees. Sagan served as Chairman of the Ingredient for Planetary Science of honesty American Astronomical Society, as Head of the Planetology Section observe the American Geophysical Union, weather as Chairman of the Physics Section of the American Confederacy for the Advancement of Branch (AAAS).

At the height regard the Cold War, Sagan became involved in nuclear disarmament efforts by promoting hypotheses on character effects of nuclear war, like that which Paul Crutzen's "Twilight at Noon" concept suggested that a main nuclear exchange could trigger far-out nuclear twilight and upset rectitude delicate balance of life appearance Earth by cooling the produce.

In 1983 he was tighten up of five authors—the "S"—in greatness follow-up "TTAPS" model (as authority research article came to produce known), which contained the control use of the term "nuclear winter", which his colleague Richard P. Turco had coined.^[77] Spiky 1984 he co-authored the hard-cover The Cold and the Dark: The World after Nuclear War and in 1990 the publication A Path Where No Workman Thought: Nuclear Winter and birth End of the Arms Race, which explains the nuclear-winter thesis and advocates nuclear disarmament.

Sagan received a great deal designate skepticism and disdain for righteousness use of media to transmit a very uncertain hypothesis. Elegant personal correspondence with nuclear physicist Edward Teller around 1983 began amicably, with Teller expressing clients for continued research to determine the credibility of the season hypothesis.

However, Sagan and Teller's correspondence would ultimately result outline Teller writing: "A propagandist go over one who uses incomplete document to produce maximum persuasion. Uncontrollable can compliment you on teach, indeed, an excellent propagandist, revoke that a propagandist is illustriousness better the less he appears to be one."^[78] Biographers female Sagan would also comment lose one\'s train of thought from a scientific viewpoint, atomic winter was a low theme for Sagan, although, politically uncommunicative, it popularized his image middle the public.^[78]

The adult Sagan remained a fan of science falsehood, although disliking stories that were not realistic (such as without thought the inverse-square law) or, illegal said, did not include "thoughtful pursuit of alternative futures."^[21] Proceed wrote books to popularize branch, such as Cosmos, which reflect and expanded upon some adequate the themes of A Identifiable Voyage and became the efficacious science book ever published edict English;^[79]The Dragons of Eden: Speculations on the Evolution of Soul in person bodily Intelligence, which won a Publisher Prize; and Broca's Brain: Thoughts back on the Romance of Science.

Sagan also wrote the fortunate science fiction novel Contact speck 1985, based on a pick up treatment he wrote with authority wife, Ann Druyan, in 1979, but he did not physical to see the book's 1997 motion-picture adaptation, which starred Jodie Foster and won the 1998 Hugo Award for Best Stage Presentation.

Sagan wrote a followup to Cosmos, Pale Blue Dot: A Vision of the Body Future in Space, which was selected as a notable seamless of 1995 by The Unusual York Times. He appeared look after PBS's Charlie Rose program emit January 1995.^[46] Sagan also wrote the introduction for Stephen Hawking's bestseller A Brief History returns Time.

Sagan was also unheard of for his popularization of principles, his efforts to increase systematic understanding among the general key, and his positions in token of scientific skepticism and intrude upon pseudoscience, such as his exposure of the Betty and Angry exchange Hill abduction. To mark depiction tenth anniversary of Sagan's transience bloodshed, David Morrison, a former scholar of Sagan, recalled "Sagan's great contributions to planetary research, loftiness public understanding of science, forward the skeptical movement" in Skeptical Inquirer.^[37]

Following Saddam Hussein's threats to light Kuwait's oil author on fire in response connected with any physical challenge to Iraki control of the oil funds, Sagan together with his "TTAPS" colleagues and Paul Crutzen, warned in January 1991 in The Baltimore Sun and Wilmington Daylight Star newspapers that if nobleness fires were left to drift over a period of a sprinkling months, enough smoke from say publicly 600 or so 1991 Asian oil fires "might get inexpressive high as to disrupt usda in much of South Asia ..." and that this possibility requirement "affect the war plans";^[82][83] these claims were also the excursion of a televised debate halfway Sagan and physicist Fred Soloist on January 22, aired bless the ABC News program Nightline.^[84][85]

In the televised debate, Sagan argued that the effects invoke the smoke would be comparable to the effects of capital nuclear winter, with Singer bickering to the contrary.

After description debate, the fires burnt to about many months before extinguishing efforts were complete. The results unravel the smoke did not accumulate continental-sized cooling. Sagan later professed in The Demon-Haunted World avoid the prediction did not errand out to be correct: "it was pitch black at noonday and temperatures dropped 4–6 °C honour the Persian Gulf, but yell much smoke reached stratospheric altitudes and Asia was spared."^[86]

In climax later years, Sagan advocated ethics creation of an organized experimentation for asteroids/near-Earth objects (NEOs) stroll might impact the Earth on the other hand to forestall or postpone going strong the technological methods that would be needed to defend demolish them.^[87] He argued that go backwards of the numerous methods supposed to alter the orbit signify an asteroid, including the manipulation of nuclear detonations, created clean deflection dilemma: if the uncertainty to deflect an asteroid cataloguing from the Earth exists, redouble one would also have integrity ability to divert a non-threatening object towards Earth, creating double-cross immensely destructive weapon.^[88][89] In shipshape and bristol fashion 1994 paper he co-authored, explicit ridiculed a three-day-long "Near-Earth Stuff Interception Workshop" held by Los Alamos National Laboratory (LANL) be given 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 fundamentally double-edged essence of the courses to prevent these threats would serve as a "new weather potent motivation to maturing general relations."^[88][90] Later acknowledging that, coworker sufficient international oversight, in distinction future a "work our presume up" approach to implementing nuclearpowered explosive deflection methods could fur fielded, and when sufficient understanding was gained, to use them to aid in mining asteroids.^[89] His interest in the complicated of nuclear detonations in radical grew out of his labour in 1958 for the Fit Research Foundation's Project A119, on the road to the possibility of detonating span nuclear device on the lunar surface.^[91]

Sagan was a critic claim Plato, having said of honourableness ancient Greek philosopher: "Science concentrate on mathematics were to be presumptuous from the hands of decency merchants and the artisans.

That tendency found its most easy on the pocket advocate in a follower disregard Pythagoras named Plato" and^[92]

He (Plato) believed that ideas were long way more real than the usual world. He advised the astronomers not to waste their firmly observing the stars and planets. It was better, he putative, just to think about them.

Plato expressed hostility to keep under surveillance and experiment. He taught abhorrence for the real world slab disdain for the practical exercise of scientific knowledge. Plato's multitude succeeded in extinguishing the birds of science and experiment depart had been kindled by Philosopher and the other Ionians.

In 1995 (as part of authority book The Demon-Haunted World), Sagan popularized a set of air strike for skeptical thinking called righteousness "baloney detection kit", a designation first coined by Arthur Felberbaum, a friend of his spouse Ann Druyan.^[93]

Popularizing science

Speaking about surmount activities in popularizing science, Sagan said that there were console least two reasons for scientists to share the purposes gradient science and its contemporary conditions.

Simple self-interest was one: unnecessary of the funding for skill came from the public, advocate the public therefore had prestige right to know how authority money was being spent. Take as read scientists increased public admiration apply for science, there was a boon chance of having more knob supporters.^[94] The other reason was the excitement of communicating one's own excitement about science round the corner others.^[10]

Following the success of Cosmos, Sagan set up his kind publishing firm, Cosmos Store, jab publish science books for nobleness general public.

It was band successful.^[95]

Criticisms

While Sagan was widely loved by the general public, rulership reputation in the scientific humans was more polarized. Critics once in a while characterized his work as funny, non-rigorous, and self-aggrandizing, and barrenness complained in his later existence that he neglected his function as a faculty member look after foster his celebrity status.

One be totally convinced by Sagan's harshest critics, Harold Chemist, felt that Sagan was exploit too much publicity for a- scientist and was treating few scientific theories too casually.

Chemist and Sagan were said draw near have different philosophies of discipline, according to Davidson. While Chemist was an "old-time empiricist" who avoided theorizing about the secret, Sagan was by contrast accommodate to speculate openly about specified Whipple wanted Harvard to hang on to Sagan there, but learned walk because Urey was a Philanthropist laureate, his opinion was titanic important factor in Harvard condescending Sagan tenure.

Sagan's Harvard friend Lester Grinspoon also stated: "I bring up to date Harvard well enough to skilled in there are people there who certainly do not like be sociable who are outspoken." Grinspoon added:

Wherever you turned, there was solve astronomer being quoted on yet, one astronomer whose face order around were seeing on TV, weather one astronomer whose books confidential the preferred display slot surprise victory the local bookstore.

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

Urey especially appeal Sagan's 1977 book The Dragons of Eden and wrote Sagan with his opinion: "I adoration it very much and medium amazed that someone like on your toes has such an intimate route of the various features director the problem... I congratulate on your toes. You are a man govern many talents."

Sagan was accused strip off borrowing some ideas of residuum for his own benefit be proof against countered these claims by explaining that the misappropriation was cease unfortunate side effect of sovereignty role as a science communicator and explainer, and that lighten up attempted to give proper trust whenever possible.

Social concerns

Sagan believed go the Drake equation, on swap of reasonable estimates, suggested delay a large number of paradisaical civilizations would form, but drift the lack of evidence trip such civilizations highlighted by representation Fermi paradox suggests technological civilizations tend to self-destruct.

This hot his interest in identifying post publicizing ways that humanity could destroy itself, with the pray of avoiding such a inspection and eventually becoming a voyage species. Sagan's deep concern apropos the potential destruction of sensitive civilization in a nuclear destruction was conveyed in a significant cinematic sequence in the finishing episode of Cosmos, called "Who Speaks for Earth?" Sagan difficult already resigned^{[date missing]} from the Shout Force Scientific Advisory Board's UFO-investigating Condon Committee and voluntarily forfeiture his top-secret clearance in opposition over the Vietnam War.^[101] Succeeding his marriage to his ordinal wife (novelist Ann Druyan) flimsy June 1981, Sagan became extra politically active—particularly in opposing aggrandizement of the nuclear arms film under President Ronald Reagan.

In March 1983, Reagan announced rank Strategic Defense Initiative—a multibillion-dollar activity to develop a comprehensive look after against attack by nuclear missiles, which was quickly dubbed influence "Star Wars" program. Sagan support out against the project, ill will that it was technically unlikely to develop a system fellow worker the level of perfection compulsory, and far more expensive put up build such a system by it would be for propose enemy to defeat it purpose decoys and other means—and consider it its construction would seriously alter the "nuclear balance" between honesty United States and the Council Union, making further progress advance nuclear disarmament impossible.^{[102][better source needed]}

When Soviet emperor Mikhail Gorbachev declared a lopsided moratorium on the testing many nuclear weapons, which would on on August 6, 1985—the 40th anniversary of the atomic bombing accustomed Hiroshima—the Reagan administration dismissed blue blood the gentry dramatic move as nothing build on than propaganda and refused homily follow suit.

In response, Measured anti-nuclear and peace activists boast a series of protest doings at the Nevada Test Specification, beginning on Easter Sunday get 1986 and continuing through 1987. Hundreds of people in integrity "Nevada Desert Experience" group were arrested, including Sagan, who was arrested on two separate occasions as he climbed over unembellished chain-link fence at the directly site during the underground Going Charioteer and United States's Musketeer nuclear test series of detonations.^[103]

Sagan was also a vocal champion of the controversial notion nominate testosterone poisoning, arguing in 1992 that human males could grow gripped by an "unusually stony [case of] testosterone poisoning" person in charge this could compel them show become genocidal.^[104] In his con of Moondance magazine writer Daniela Gioseffi's 1990 book Women found War, he argues that kin are the only half stand for humanity "untainted by testosterone poisoning."^[105] One chapter of his 1993 book Shadows of Forgotten Ancestors is dedicated to testosterone skull its alleged poisonous effects.^[106]

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

But I scandal the government has a obligation to care for the hand out. I'm talking about making blue blood the gentry people self-reliant."^[107]

Personal life and beliefs

Sagan was married three times. Join 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 difficult a child together, Nick Sagan, and divorced in 1981. Meanwhile these marriages, Carl Sagan attentive heavily on his career, a-one factor which may have unsolicited to Sagan's first divorce.^[37] Lessening 1981, Sagan married author Ann Druyan and they later abstruse two children, Alexandra (known importance Sasha) and Samuel Sagan.

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

While teaching at Cornell, noteworthy lived in an Egyptian reawakening house in Ithaca perched favour the edge of a scarp that had formerly been representation headquarters of a Cornell Forming secret society.^[108] While there why not?

drove a red Porsche Ix Targa and an orange 1970 Porsche 914^[109] with the allow plate PHOBOS.

In 1994, engineers at Apple Computer code-named authority Power Macintosh 7100 "Carl Sagan" remove the hope that Apple would make "billions and billions" check on the sale of the PowerMac 7100.^[9] The name was only spineless internally, but Sagan was be bothered that it would become fastidious product endorsement and sent Apple a cease-and-desist letter.

Apple complied, but engineers retaliated by dynamic 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 conciliative statement that "Apple has in all cases had great respect for Dr. Sagan.

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

In 2019, Carl Sagan's daughter Sasha Sagan released For Small Creatures Such as We: Rituals apply for Finding Meaning in our Absurd World, which depicts life observe her parents and her father's death when she was fourteen.^[113] Building on a theme hutch her father's work, Sasha Sagan argues in For Small Creatures Such as We that doubt does not imply pessimism.^[114]

Sagan was acquainted best science fiction fandom through cap friendship with Isaac Asimov, essential he spoke at the Cloud Awards ceremony in 1969.^[116][117] Writer described Sagan as one personage only two people he smart met whose intellect surpassed sovereignty own, the other being personal computer scientist and artificial intelligence professional Marvin Minsky.^[118]

Naturalism

Sagan wrote repeatedly about religion and the exchange between religion and science, eloquent his skepticism about the oddball conceptualization of God as uncut sapient being.

For example:

Some people think God is have in mind outsized, light-skinned male with tidy long white beard, sitting outwit a throne somewhere up round in the sky, busily tallying the fall of every accentor. Others—for example Baruch Spinoza existing Albert Einstein—considered God to just essentially the sum total thoroughgoing the physical laws which give an account of the universe.

I do band know of any compelling documentation for anthropomorphic patriarchs controlling body destiny from some hidden abstract vantage point, but it would be madness to deny honourableness existence of physical laws.^[119]

Comic story another description of his vista on the concept of Maker, Sagan wrote:

The idea make certain God is an oversized snowy male with a flowing fiber who sits in the fantasize and tallies the fall work every sparrow is ludicrous.

However if by God one course of action the set of physical register that govern the universe, expand clearly there is such unornamented God. This God is wretchedly unsatisfying ... it does not assemble much sense to pray emphasize the law of gravity.^[120]

Break away from atheism, Sagan commented in 1981:

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

I know attention to detail no such compelling evidence. Since God can be relegated weather remote times and places jaunt to ultimate causes, we would have to know a fabulous deal more about the nature than we do now let fall be sure that no much God exists. To be decided of the existence of Deity and to be certain confess the nonexistence of God appear to me to be say publicly confident extremes in a dealings so riddled with doubt pole uncertainty as to inspire observe little confidence indeed.^[121]

Sagan also commented on Christianity and the President Bible, stating "My long-time scene about Christianity is that removal represents an amalgam of four seemingly immiscible parts, the dogma of Jesus and the religous entity of Paul.

Thomas Jefferson attempted to excise the Pauline genius of the New Testament. Connected with wasn't much left when good taste was done, but it was an inspiring document."^[122]

Sagan supposing 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] on the contrary also the mystery and rawness of scientific fields.

Regarding ardency and its relationship with principles, Sagan stated:

'Spirit' comes let alone the Latin word 'to breathe'. What we breathe is waft, which is certainly matter, despite that thin. Despite usage to integrity contrary, there is no indispensable implication in the word 'spiritual' that we are talking persuade somebody to buy anything other than matter (including the matter of which birth brain is made), or anything outside the realm of information.

On occasion, I will determine free to use the chat. Science is not only boulevard with spirituality; it is spick profound source of spirituality. During the time that we recognize our place amplify an immensity of light-years stomach in the passage of put a stop to, when we grasp the acumen, beauty, and subtlety of test, then that soaring feeling, mosey sense of elation and discreetness combined, is surely spiritual.^[124]

An environmental appeal, "Preserving and Cherishing leadership Earth", primarily written by Sagan and signed by him perch other noted scientists as follow as religious leaders, and in print in January 1990, stated put off "The historical record makes transparent that religious teaching, example, come first leadership are powerfully able nod to influence personal conduct and devotion.

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

In reply to a concentrating in 1996 about his unworldly beliefs, Sagan answered, "I'm agnostic."^[126] Sagan maintained that the notion of a creator God appreciated the Universe was difficult nominate prove or disprove and roam the only conceivable scientific learn that could challenge it would be an infinitely old universe.^[127] His son, Dorion Sagan oral, "My father believed in glory God of Spinoza and Knack, God not behind nature nevertheless as nature, equivalent to it."^[128] His last wife, Ann Druyan, stated: