Carl Edward Sagan (; ; November 9, 1934December 20, 1996) was an American
astronomer
An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, g ...
,
planetary scientist
Planetary science (or more rarely, planetology) is the scientific study of planets (including Earth), celestial bodies (such as moons, asteroids, comets) and planetary systems (in particular those of the Solar System) and the processes of their ...
,
cosmologist
Cosmology () is a branch of physics and metaphysics dealing with the nature of the universe. The term ''cosmology'' was first used in English in 1656 in Thomas Blount's ''Glossographia'', and in 1731 taken up in Latin by German philosopher ...
astrobiologist
Astrobiology, and the related field of exobiology, is an interdisciplinary scientific field that studies the origins, early evolution, distribution, and future of life in the universe. Astrobiology is the multidisciplinary field that inves ...
, author, and
science communicator
Science communication is the practice of informing, educating, raising awareness of science-related topics, and increasing the sense of wonder about scientific discoveries and arguments. Science communicators and audiences are ambiguously def ...
. His best known scientific contribution is research on
extraterrestrial life
Extraterrestrial life, colloquially referred to as alien life, is life that may occur outside Earth and which did not originate on Earth. No extraterrestrial life has yet been conclusively detected, although efforts are underway. Such life might ...
, including experimental demonstration of the production of
amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...
s from basic chemicals by
radiation
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes:
* ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...
. Sagan assembled the first physical messages sent into space, the
Pioneer plaque
The Pioneer plaques are a pair of gold-anodized aluminum plaques that were placed on board the 1972 ''Pioneer 10'' and 1973 ''Pioneer 11'' spacecraft, featuring a pictorial message, in case either ''Pioneer 10'' or ''11'' is intercepted by inte ...
and the
Voyager Golden Record
The Voyager Golden Records are two phonograph records that were included aboard both Voyager spacecraft launched in 1977. The records contain sounds and images selected to portray the diversity of life and culture on Earth, and are intended for ...
, universal messages that could potentially be understood by any extraterrestrial intelligence that might find them. Sagan argued the hypothesis, accepted since, that the high surface temperatures of
Venus
Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never fa ...
can be attributed to, and calculated using, the
greenhouse effect
The greenhouse effect is a process that occurs when energy from a planet's host star goes through the planet's atmosphere and heats the planet's surface, but greenhouse gases in the atmosphere prevent some of the heat from returning directly ...
Harvard
Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...
, Sagan later moved to
Cornell
Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to teach an ...
where he would spend the majority of his career. Sagan published more than 600 scientific papers and articles and was author, co-author or editor of more than 20 books. He wrote many
popular science
''Popular Science'' (also known as ''PopSci'') is an American digital magazine carrying popular science content, which refers to articles for the general reader on science and technology subjects. ''Popular Science'' has won over 58 awards, incl ...
books, such as ''
The Dragons of Eden
''The Dragons of Eden: Speculations on the Evolution of Human Intelligence'' is a 1977 book by Carl Sagan, in which the author combines the fields of anthropology, evolutionary biology, psychology, and computer science to give a perspective on ho ...
'', ''
Broca's Brain
''Broca's Brain: Reflections on the Romance of Science'' is a 1979 book by the astrophysicist Carl Sagan. Its chapters were originally articles published between 1974 and 1979 in various magazines, including ''The Atlantic Monthly'', ''The New R ...
'', ''
Pale Blue Dot
''Pale Blue Dot'' is a photograph of planet Earth taken on February 14, 1990, by the ''Voyager 1'' space probe from a record distance of about kilometers ( miles, 40.5 AU), as part of that day's ''Family Portrait'' series of images of the ...
'' and narrated and co-wrote the award-winning 1980 television series '' Cosmos: A Personal Voyage''. The most widely watched series in the history of American
public television
Public broadcasting involves radio, television and other electronic media outlets whose primary mission is public service. Public broadcasters receive funding from diverse sources including license fees, individual contributions, public financing ...
, ''Cosmos'' has been seen by at least 500 million people in 60 countries. The book ''
Cosmos
The cosmos (, ) is another name for the Universe. Using the word ''cosmos'' implies viewing the universe as a complex and orderly system or entity.
The cosmos, and understandings of the reasons for its existence and significance, are studied in ...
'' was published to accompany the series. He also wrote the 1985 science fiction novel ''
Contact
Contact may refer to:
Interaction Physical interaction
* Contact (geology), a common geological feature
* Contact lens or contact, a lens placed on the eye
* Contact sport, a sport in which players make contact with other players or objects
* ...
'', the basis for a 1997 film of the same name. His papers, containing 595,000 items, are archived at
The Library of Congress
The Library of Congress (LOC) is the research library that officially serves the United States Congress and is the ''de facto'' national library of the United States. It is the oldest federal cultural institution in the country. The library is ...
scientific method
The scientific method is an empirical method for acquiring knowledge that has characterized the development of science since at least the 17th century (with notable practitioners in previous centuries; see the article history of scientific m ...
, pioneered
exobiology
Astrobiology, and the related field of exobiology, is an interdisciplinary scientific field that studies the origins, early evolution, distribution, and future of life in the universe. Astrobiology is the multidisciplinary field that investig ...
and promoted the Search for Extra-Terrestrial Intelligence (
SETI
The search for extraterrestrial intelligence (SETI) is a collective term for scientific searches for intelligent extraterrestrial life, for example, monitoring electromagnetic radiation for signs of transmissions from civilizations on other p ...
). He spent most of his career as a professor of astronomy at
Cornell University
Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to teach an ...
, where he directed the Laboratory for Planetary Studies. Sagan and his works received numerous awards and honors, including the
NASA Distinguished Public Service Medal
The NASA Distinguished Public Service Medal is an award similar to the NASA Distinguished Service Medal, but awarded to non-government personnel. This is the highest honor NASA awards to anyone who was not a government employee when the service ...
, the
National Academy of Sciences
The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...
Public Welfare Medal The Public Welfare Medal is awarded by the U.S. National Academy of Sciences "in recognition of distinguished contributions in the application of science to the public welfare." It is the most prestigious honor conferred by the academy. First award ...
, the
Pulitzer Prize for General Non-Fiction
The Pulitzer Prize for General Nonfiction is one of the seven American Pulitzer Prizes that are awarded annually for the "Letters, Drama, and Music" category. The award is given to a nonfiction book written by an American author and published duri ...
for his book ''The Dragons of Eden'', and, regarding ''Cosmos: A Personal Voyage'', two
Emmy Award
The Emmy Awards, or Emmys, are an extensive range of awards for artistic and technical merit for the American and international television industry. A number of annual Emmy Award ceremonies are held throughout the calendar year, each with the ...
s, the
Peabody Award
The George Foster Peabody Awards (or simply Peabody Awards or the Peabodys) program, named for the American businessman and philanthropist George Peabody, honor the most powerful, enlightening, and invigorating stories in television, radio, and ...
, and the
Hugo Award
The Hugo Award is an annual literary award for the best science fiction or fantasy works and achievements of the previous year, given at the World Science Fiction Convention and chosen by its members. The Hugo is widely considered the premier a ...
. He married three times and had five children. After developing
myelodysplasia
A myelodysplastic syndrome (MDS) is one of a group of cancers in which immature blood cells in the bone marrow do not mature, and as a result, do not develop into healthy blood cells. Early on, no symptoms typically are seen. Later, symptoms may ...
, Sagan died of
pneumonia
Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity ...
at the age of 62, on December 20, 1996.
Early life and education
Sagan was born in the
Bensonhurst
Bensonhurst is a residential neighborhood in the southwestern section of the New York City borough of Brooklyn. The neighborhood is bordered on the northwest by 14th Avenue, on the northeast by 60th Street, on the southeast by Avenue P and 22n ...
neighborhood of
Brooklyn
Brooklyn () is a borough of New York City, coextensive with Kings County, in the U.S. state of New York. Kings County is the most populous county in the State of New York, and the second-most densely populated county in the United States, be ...
, New York, on November 9, 1934.Poundstone 1999, pp. 363–364, 374–375. His father, Samuel Sagan, was an immigrant
garment worker
Clothing industry or garment industry summarizes the types of trade and industry along the production and value chain of clothing and garments, starting with the textile industry (producers of cotton, wool, fur, and synthetic fibre), embellishme ...
Russian Empire
The Russian Empire was an empire and the final period of the Russian monarchy from 1721 to 1917, ruling across large parts of Eurasia. It succeeded the Tsardom of Russia following the Treaty of Nystad, which ended the Great Northern War. ...
, in today's
Ukraine
Ukraine ( uk, Україна, Ukraïna, ) is a country in Eastern Europe. It is the second-largest European country after Russia, which it borders to the east and northeast. Ukraine covers approximately . Prior to the ongoing Russian inv ...
. His mother, Rachel Molly Gruber, was a housewife from New York. Carl was named in honor of Rachel's
biological mother
]
A mother is the female parent of a child. A woman may be considered a mother by virtue of having given birth, by raising a child who may or may not be her biological offspring, or by supplying her ovum for fertilisation in the case of gesta ...
, Chaiya Clara, in Sagan's words, "the mother she never knew",#Davidson, Davidson 1999. because she died while giving birth to her second child. Rachel's father remarried a woman named Rose. According to Carol (Carl's sister), Rachel "never accepted Rose as her mother. She knew she wasn't her birth mother... She was a rather rebellious child and young adult ... 'emancipated woman', we'd call her now."
The family lived in a modest apartment near the Atlantic Ocean, in
Bensonhurst
Bensonhurst is a residential neighborhood in the southwestern section of the New York City borough of Brooklyn. The neighborhood is bordered on the northwest by 14th Avenue, on the northeast by 60th Street, on the southeast by Avenue P and 22n ...
, a Brooklyn neighborhood. According to Sagan, they were
Reform Jews
Reform Judaism, also known as Liberal Judaism or Progressive Judaism, is a major Jewish denomination that emphasizes the evolving nature of Judaism, the superiority of its ethical aspects to its ceremonial ones, and belief in a continuous searc ...
, the most
liberal
Liberal or liberalism may refer to:
Politics
* a supporter of liberalism
** Liberalism by country
* an adherent of a Liberal Party
* Liberalism (international relations)
* Sexually liberal feminism
* Social liberalism
Arts, entertainment and m ...
of North American Judaism's four main groups. Carl and his sister agreed that their father was not especially religious, but that their mother "definitely believed in God, and was active in the temple; ... and served only
kosher
(also or , ) is a set of dietary laws dealing with the foods that Jewish people are permitted to eat and how those foods must be prepared according to Jewish law. Food that may be consumed is deemed kosher ( in English, yi, כּשר), fro ...
meat". During the depths of the Depression, his father worked as a theater usher.
According to biographer Keay Davidson, Sagan's "inner war" was a result of his close relationship with both of his parents, who were in many ways "opposites". Sagan traced his later analytical urges to his mother, a woman who had been extremely poor as a child in New York City during
World War I
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
and the 1920s. As a young woman, she had held her own intellectual ambitions, but they were frustrated by social restrictions: her poverty, her status as a woman and a wife, and her
Jewish ethnicity
Jews ( he, יְהוּדִים, , ) or Jewish people are an ethnoreligious group and nation originating from the Israelites Israelite origins and kingdom: "The first act in the long drama of Jewish history is the age of the Israelites""The ...
. Davidson notes that she therefore "worshipped her only son, Carl. He would fulfill her unfulfilled dreams."
However, he claimed that his sense of wonder came from his father, who in his free time gave apples to the poor or helped soothe labor-management tensions within New York's garment industry. Although he was awed by Carl's intellectual abilities, he took his son's inquisitiveness in stride and saw it as part of his growing up. In his later years as a writer and scientist, Sagan would often draw on his childhood memories to illustrate scientific points, as he did in his book '' Shadows of Forgotten Ancestors''. Sagan describes his parents' influence on his later thinking:Spangenburg & Moser 2004, pp. 2–5.
Sagan recalls that one of his most defining moments was when his parents took him to the
1939 New York World's Fair
The 1939–40 New York World's Fair was a world's fair held at Flushing Meadows–Corona Park in Queens, New York, United States. It was the second-most expensive American world's fair of all time, exceeded only by St. Louis's Louisiana Purchas ...
when he was four years old. The exhibits became a turning point in his life. He later recalled the moving map of the '' America of Tomorrow'' exhibit: "It showed beautiful highways and cloverleaves and little General Motors cars all carrying people to skyscrapers, buildings with lovely spires, flying buttresses—and it looked great!" At other exhibits, he remembered how a flashlight that shone on a
photoelectric cell
A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.
created a crackling sound, and how the sound from a
tuning fork
A tuning fork is an acoustic resonator in the form of a two-pronged fork with the prongs (tines) formed from a U-shaped bar of elastic metal (usually steel). It resonates at a specific constant pitch when set vibrating by striking it against ...
became a wave on an
oscilloscope
An oscilloscope (informally a scope) is a type of electronic test instrument that graphically displays varying electrical voltages as a two-dimensional plot of one or more signals as a function of time. The main purposes are to display repetiti ...
. He also witnessed the future media technology that would replace radio: television. Sagan wrote:
He also saw one of the Fair's most publicized events, the burial of a
time capsule
A time capsule is a historic cache of goods or information, usually intended as a deliberate method of communication with future people, and to help future archaeologists, anthropologists, or historians. The preservation of holy relics dates ba ...
at
Flushing Meadows
Flushing may refer to:
Places
* Flushing, Cornwall, a village in the United Kingdom
* Flushing, Queens, New York City
** Flushing Bay, a bay off the north shore of Queens
** Flushing Chinatown (法拉盛華埠), a community in Queens
** Flushin ...
, which contained mementos of the 1930s to be recovered by Earth's descendants in a future millennium. "The time capsule thrilled Carl", writes Davidson. As an adult, Sagan and his colleagues would create similar time capsules—capsules that would be sent out into the galaxy; these were the
Pioneer plaque
The Pioneer plaques are a pair of gold-anodized aluminum plaques that were placed on board the 1972 ''Pioneer 10'' and 1973 ''Pioneer 11'' spacecraft, featuring a pictorial message, in case either ''Pioneer 10'' or ''11'' is intercepted by inte ...
and the ''
Voyager Golden Record
The Voyager Golden Records are two phonograph records that were included aboard both Voyager spacecraft launched in 1977. The records contain sounds and images selected to portray the diversity of life and culture on Earth, and are intended for ...
'' précis, all of which were spinoffs of Sagan's memories of the World's Fair.
During
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...
Sagan's family worried about the fate of their European relatives. Sagan, however, was generally unaware of the details of the ongoing war. He wrote, "Sure, we had relatives who were caught up in the
Holocaust
The Holocaust, also known as the Shoah, was the genocide of European Jews during World War II. Between 1941 and 1945, Nazi Germany and its collaborators systematically murdered some six million Jews across German-occupied Europe; a ...
.
Hitler
Adolf Hitler (; 20 April 188930 April 1945) was an Austrian-born German politician who was dictator of Germany from 1933 until his death in 1945. He rose to power as the leader of the Nazi Party, becoming the chancellor in 1933 and then ...
was not a popular fellow in our household... But on the other hand, I was fairly insulated from the horrors of the war." His sister, Carol, said that their mother "above all wanted to protect Carl... She had an extraordinarily difficult time dealing with World War II and the Holocaust." Sagan's book ''
The Demon-Haunted World
''The Demon-Haunted World: Science as a Candle in the Dark'' is a 1995 book by the astrophysicist Carl Sagan and co-authored by Ann Druyan, in which the authors aim to explain the scientific method to laypeople and to encourage people to learn c ...
'' (1996) included his memories of this conflicted period, when his family dealt with the realities of the war in Europe but tried to prevent it from undermining his optimistic spirit.
Inquisitiveness about nature
Soon after entering elementary school he began to express a strong inquisitiveness about nature. Sagan recalled taking his first trips to the public library alone, at the age of five, when his mother got him a library card. He wanted to learn what stars were, since none of his friends or their parents could give him a clear answer:
At about age six or seven, he and a close friend took trips to the
American Museum of Natural History
The American Museum of Natural History (abbreviated as AMNH) is a natural history museum on the Upper West Side of Manhattan in New York City. In Theodore Roosevelt Park, across the street from Central Park, the museum complex comprises 26 inter ...
across the East River in
Manhattan
Manhattan (), known regionally as the City, is the most densely populated and geographically smallest of the five boroughs of New York City. The borough is also coextensive with New York County, one of the original counties of the U.S. state ...
. While there, they went to the
Hayden Planetarium
The Rose Center for Earth and Space is a part of the American Museum of Natural History in New York City. The Center's complete name is The Frederick Phineas and Sandra Priest Rose Center for Earth and Space. The main entrance is located on the n ...
and walked around the museum's exhibits of
space
Space is the boundless three-dimensional extent in which objects and events have relative position and direction. In classical physics, physical space is often conceived in three linear dimensions, although modern physicists usually consider ...
objects, such as
meteorite
A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or Natural satellite, moon. When the ...
s, and displays of dinosaurs and animals in natural settings. Sagan writes about those visits:
His parents helped nurture his growing interest in science by buying him chemistry sets and reading materials. His interest in space, however, was his primary focus, especially after reading science fiction stories by writers such as
Edgar Rice Burroughs
Edgar Rice Burroughs (September 1, 1875 – March 19, 1950) was an American author, best known for his prolific output in the adventure, science fiction, and fantasy genres. Best-known for creating the characters Tarzan and John Carter, he ...
, which stirred his imagination about life on other planets such as
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...
. According to biographer Ray Spangenburg, these early years as Sagan tried to understand the mysteries of the planets became a "driving force in his life, a continual spark to his intellect, and a quest that would never be forgotten".
In 1947 he discovered ''
Astounding Science Fiction
''Analog Science Fiction and Fact'' is an American science fiction magazine published under various titles since 1930. Originally titled ''Astounding Stories of Super-Science'', the first issue was dated January 1930, published by William C ...
'' magazine, which introduced him to more
hard science fiction
Hard science fiction is a category of science fiction characterized by concern for scientific accuracy and logic. The term was first used in print in 1957 by P. Schuyler Miller in a review of John W. Campbell's ''Islands of Space'' in the Novemb ...
speculations than those in Burroughs's novels. That same year inaugurated the "
flying saucer
A flying saucer (also referred to as "a flying disc") is a descriptive term for a type of flying craft having a disc or saucer-shaped body, commonly used generically to refer to an anomalous flying object. The term was coined in 1947 but has g ...
"
mass hysteria
Mass psychogenic illness (MPI), also called mass sociogenic illness, mass psychogenic disorder, epidemic hysteria, or mass hysteria, involves the spread of illness symptoms through a population where there is no infectious agent responsible for c ...
with the young Carl suspecting that the "discs" might be alien spaceships.
High-school years
Sagan had lived in Bensonhurst, where he went to David A. Boody Junior High School. He had his bar mitzvah in Bensonhurst when he turned 13. The following year, 1948, his family moved to the town of
Rahway, New Jersey
Rahway () is a city in southern Union County, in the U.S. state of New Jersey. A bedroom community of New York City, it is centrally located in the Rahway Valley region, in the New York metropolitan area. The city is southwest of Manhattan ...
, for his father's work, where Sagan then entered
Rahway High School
Rahway High School is a four-year public high school that serves students in ninth through twelfth grades from Rahway, in Union County, New Jersey, United States, operating as the lone secondary school of the Rahway Public Schools. The high s ...
. He graduated in 1951. Rahway was an older semi-industrial town.
Sagan was a straight-A student but was bored due to unchallenging classes and uninspiring teachers. His teachers realized this and tried to convince his parents to send him to a private school, the administrator telling them, "This kid ought to go to a school for gifted children, he has something really remarkable." However, his parents could not afford it.
Sagan was made president of the school's chemistry club, and at home he set up his own laboratory. He taught himself about molecules by making cardboard cutouts to help him visualize how molecules were formed: "I found that about as interesting as doing hemicalexperiments," he said. Sagan remained mostly interested in astronomy as a hobby and in his junior year made it a career goal after he learned that astronomers were paid for doing what he always enjoyed: "That was a splendid day—when I began to suspect that if I tried hard I could do astronomy full-time, not just part-time."
Before the end of high school, he entered an essay contest in which he posed the question of whether human contact with advanced life forms from another planet might be as disastrous for people on Earth as it was for Native Americans when they first had contact with Europeans.Poundstone 1999, p. 15. The subject was considered controversial, but his rhetorical skill won over the judges, and they awarded him first prize. By graduation, his classmates had voted him "most likely to succeed" and put him in line to be valedictorian.
University education
Sagan attended the
University of Chicago
The University of Chicago (UChicago, Chicago, U of C, or UChi) is a private research university in Chicago, Illinois. Its main campus is located in Chicago's Hyde Park neighborhood. The University of Chicago is consistently ranked among the b ...
, which was one of the few colleges he applied to that would, despite his excellent high-school grades, consider admitting a 16-year-old. Its chancellor,
Robert Maynard Hutchins
Robert Maynard Hutchins (January 17, 1899 – May 14, 1977) was an American educational philosopher. He was president (1929–1945) and chancellor (1945–1951) of the University of Chicago, and earlier dean of Yale Law School (1927–1929). His& ...
, had recently retooled the undergraduate
College of the University of Chicago
The College of the University of Chicago is the university's sole undergraduate institution and one of its oldest components, emerging contemporaneously with the university's Hyde Park campus in 1892. Instruction is provided by faculty from acros ...
into an "ideal meritocracy" built on
Great Books
A classic is a book accepted as being exemplary or particularly noteworthy. What makes a book "classic" is a concern that has occurred to various authors ranging from Italo Calvino to Mark Twain and the related questions of "Why Read the Cl ...
,
Socratic dialogue
Socratic dialogue ( grc, Σωκρατικὸς λόγος) is a genre of literary prose developed in Greece at the turn of the fourth century BC. The earliest ones are preserved in the works of Plato and Xenophon and all involve Socrates as the p ...
,
comprehensive examination
In higher education, a comprehensive examination (or comprehensive exam or exams), often abbreviated as "comps", is a specific type of examination that must be completed by graduate students in some disciplines and courses of study, and also by un ...
Enrico Fermi
Enrico Fermi (; 29 September 1901 – 28 November 1954) was an Italian (later naturalized American) physicist and the creator of the world's first nuclear reactor, the Chicago Pile-1. He has been called the "architect of the nuclear age" and ...
and
Edward Teller
Edward Teller ( hu, Teller Ede; January 15, 1908 – September 9, 2003) was a Hungarian-American theoretical physicist who is known colloquially as "the father of the hydrogen bomb" (see the Teller–Ulam design), although he did not care fo ...
, and operated the famous
Yerkes Observatory
Yerkes Observatory ( ) is an astronomical observatory located in Williams Bay, Wisconsin, United States. The observatory was operated by the University of Chicago Department of Astronomy and Astrophysics from its founding in 1897 to 2018. Owne ...
.
During his time as an honors program
undergraduate
Undergraduate education is education conducted after secondary education and before postgraduate education. It typically includes all postsecondary programs up to the level of a bachelor's degree. For example, in the United States, an entry-lev ...
, Sagan worked in the laboratory of the
geneticist
A geneticist is a biologist or physician who studies genetics, the science of genes, heredity, and variation of organisms. A geneticist can be employed as a scientist or a lecturer. Geneticists may perform general research on genetic processe ...
origins of life
In biology, abiogenesis (from a- 'not' + Greek bios 'life' + genesis 'origin') or the origin of life is the natural process by which life has arisen from non-living matter, such as simple organic compounds. The prevailing scientific hypothes ...
with
physical chemist
Physical chemistry is the study of macroscopic and microscopic phenomena in chemical systems in terms of the principles, practices, and concepts of physics such as motion, energy, force, time, thermodynamics, quantum chemistry, statistical me ...
Harold Urey
Harold Clayton Urey ( ; April 29, 1893 – January 5, 1981) was an American physical chemist whose pioneering work on isotopes earned him the Nobel Prize in Chemistry in 1934 for the discovery of deuterium. He played a significant role in the d ...
. Sagan joined the Ryerson Astronomical Society, received a
B.A.
Bachelor of arts (BA or AB; from the Latin ', ', or ') is a bachelor's degree awarded for an undergraduate program in the arts, or, in some cases, other disciplines. A Bachelor of Arts degree course is generally completed in three or four yea ...
degree in laughingly self-proclaimed "nothing" with general and special honors in 1954, and a
B.S.
A Bachelor of Science (BS, BSc, SB, or ScB; from the Latin ') is a bachelor's degree awarded for programs that generally last three to five years.
The first university to admit a student to the degree of Bachelor of Science was the University ...
degree in
physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...
in 1955. He went on to earn a
M.S.
A Master of Science ( la, Magisterii Scientiae; abbreviated MS, M.S., MSc, M.Sc., SM, S.M., ScM or Sc.M.) is a master's degree in the field of science awarded by universities in many countries or a person holding such a degree. In contrast to ...
degree in
physics
Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...
in 1956, before earning a PhD degree in 1960 with his thesis ''Physical Studies of the Planets'' submitted to the Department of Astronomy and Astrophysics.
He used the summer months of his
graduate studies
Postgraduate or graduate education refers to academic or professional degrees, certificates, diplomas, or other qualifications pursued by post-secondary students who have earned an undergraduate (bachelor's) degree.
The organization and stru ...
planetary scientist
Planetary science (or more rarely, planetology) is the scientific study of planets (including Earth), celestial bodies (such as moons, asteroids, comets) and planetary systems (in particular those of the Solar System) and the processes of their ...
Gerard Kuiper
Gerard Peter Kuiper (; ; born Gerrit Pieter Kuiper; 7 December 1905 – 23 December 1973) was a Dutch astronomer, planetary scientist, selenographer, author and professor. He is the eponymous namesake of the Kuiper belt.
Kuiper is ...
, as well as physicist
George Gamow
George Gamow (March 4, 1904 – August 19, 1968), born Georgiy Antonovich Gamov ( uk, Георгій Антонович Гамов, russian: Георгий Антонович Гамов), was a Russian-born Soviet and American polymath, theoret ...
and chemist
Melvin Calvin
Melvin Ellis Calvin (April 8, 1912 – January 8, 1997) was an American biochemist known for discovering the Calvin cycle along with Andrew Benson and James Bassham, for which he was awarded the 1961 Nobel Prize in Chemistry. He spent most of h ...
. The title of Sagan's dissertation reflects his shared interests with Kuiper, who throughout the 1950s had been president of the
International Astronomical Union
The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreac ...
's commission on "Physical Studies of Planets and Satellites". In 1958, the two worked on the classified military
Project A119
Project A119, also known as A Study of Lunar Research Flights, was a top-secret plan developed in 1958 by the United States Air Force. The aim of the project was to detonate a nuclear bomb on the Moon, which would help in answering some of th ...
, the secret Air Force plan to detonate a nuclear warhead on the Moon.
Sagan had a
Top Secret
Classified information is material that a government body deems to be sensitive information that must be protected. Access is restricted by law or regulation to particular groups of people with the necessary security clearance and need to know, ...
clearance at the
U.S. Air Force
The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Sign ...
and a
Secret
Secrecy is the practice of hiding information from certain individuals or groups who do not have the "need to know", perhaps while sharing it with other individuals. That which is kept hidden is known as the secret.
Secrecy is often controvers ...
clearance with NASA. While working on his doctoral dissertation, Sagan revealed US Government classified titles of two
Project A119
Project A119, also known as A Study of Lunar Research Flights, was a top-secret plan developed in 1958 by the United States Air Force. The aim of the project was to detonate a nuclear bomb on the Moon, which would help in answering some of th ...
papers when he applied for a University of California, Berkeley scholarship in 1959. The leak was not publicly revealed until 1999, when it was published in the journal ''
Nature
Nature, in the broadest sense, is the physics, physical world or universe. "Nature" can refer to the phenomenon, phenomena of the physical world, and also to life in general. The study of nature is a large, if not the only, part of science. ...
''. A follow-up letter to the journal by project leader Leonard Reiffel confirmed Sagan's security leak.
Career and research
From 1960 to 1962 Sagan was a Miller Research Fellows, Miller Fellow at the University of California, Berkeley. Meanwhile, he published an article in 1961 in the journal ''Science'' on the atmosphere of Venus, while also working with NASA's Mariner 2 team, and served as a "Planetary Sciences Consultant" to the RAND Corporation.
After the publication of Sagan's ''Science'' article, in 1961 Harvard University astronomers Fred Whipple and Donald Menzel offered Sagan the opportunity to give a colloquium at Harvard and subsequently offered him a Academic ranks in the United States, lecturer position at the institution. Sagan instead asked to be made an assistant professor, and eventually Whipple and Menzel were able to convince Harvard to offer Sagan the assistant professor position he requested. Sagan lectured, performed research, and advised graduate students at the institution from 1963 until 1968, as well as working at the Smithsonian Astrophysical Observatory, also located in Cambridge, Massachusetts.
In 1968, Sagan was denied Tenure (academic), tenure at Harvard. He later indicated that the decision was very much unexpected. The tenure denial has been blamed on several factors, including that he focused his interests too broadly across a number of areas (while the norm in academia is to become a renowned expert in a narrow specialty), and perhaps because of his well-publicized scientific advocacy, which some scientists perceived as borrowing the ideas of others for little more than self-promotion. An advisor from his years as an undergraduate student,
Harold Urey
Harold Clayton Urey ( ; April 29, 1893 – January 5, 1981) was an American physical chemist whose pioneering work on isotopes earned him the Nobel Prize in Chemistry in 1934 for the discovery of deuterium. He played a significant role in the d ...
, wrote a letter to the tenure committee recommending strongly against tenure for Sagan.
Long before the ill-fated tenure process, Cornell University astronomer Thomas Gold had courted Sagan to move to Ithaca, New York, and join the faculty at Cornell. Following the denial of tenure from Harvard, Sagan accepted Gold's offer and remained a faculty member at Cornell for nearly 30 years until his death in 1996. Unlike Harvard, the smaller and more laid-back astronomy department at Cornell welcomed Sagan's growing celebrity status. Following two years as an associate professor, Sagan became a Professor, full professor at Cornell in 1970 and directed the Laboratory for Planetary Studies there. From 1972 to 1981, he was associate director of the Center for Radiophysics and Space Research (CRSR) at Cornell. In 1976, he became the David Duncan Professor of Astronomy and Space Sciences, a position he held for the remainder of his life.
Sagan was associated with the U.S. space program from its inception. From the 1950s onward, he worked as an advisor to NASA, where one of his duties included briefing the Apollo program, Apollo astronauts before their flights to the Moon. Sagan contributed to many of the robotic spacecraft missions that explored the Solar System, arranging experiments on many of the expeditions. Sagan assembled the first physical message that was sent into space: a Gold plating, gold-plated Pioneer plaque, plaque, attached to the space probe ''Pioneer 10'', launched in 1972. ''Pioneer 11'', also carrying another copy of the plaque, was launched the following year. He continued to refine his designs; the most elaborate message he helped to develop and assemble was the
Voyager Golden Record
The Voyager Golden Records are two phonograph records that were included aboard both Voyager spacecraft launched in 1977. The records contain sounds and images selected to portray the diversity of life and culture on Earth, and are intended for ...
, which was sent out with the Voyager program, Voyager space probes in 1977. Sagan often challenged the decisions to fund the Space Shuttle and the International Space Station at the expense of further robotic missions.
Scientific achievements
Former student David Morrison (astrophysicist), David Morrison described Sagan as "an 'idea person' and a master of intuitive physical arguments and 'Back-of-the-envelope calculation, back of the envelope' calculations", and
Gerard Kuiper
Gerard Peter Kuiper (; ; born Gerrit Pieter Kuiper; 7 December 1905 – 23 December 1973) was a Dutch astronomer, planetary scientist, selenographer, author and professor. He is the eponymous namesake of the Kuiper belt.
Kuiper is ...
said that "Some persons work best in specializing on a major program in the laboratory; others are best in liaison between sciences. Dr. Sagan belongs in the latter group."
Sagan's contributions were central to the discovery of the high surface temperatures of the planet
Venus
Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never fa ...
. In the early 1960s no one knew for certain the basic conditions of Venus' surface, and Sagan listed the possibilities in a report later depicted for popularization in a Time Life book ''Planets''. His own view was that Venus was dry and very hot as opposed to the balmy paradise others had imagined. He had investigated radio waves from Venus and concluded that there was a surface temperature of . As a visiting scientist to NASA's Jet Propulsion Laboratory, he contributed to the first Mariner program, Mariner missions to Venus, working on the design and management of the project. Mariner 2 confirmed his conclusions on the surface conditions of Venus in 1962.
Sagan was among the first to hypothesize that Saturn's moon Titan (moon), Titan might possess oceans of liquid compounds on its surface and that Jupiter's moon Europa (moon), Europa might possess subsurface oceans of water. This would make Europa potentially habitable. Europa's subsurface ocean of water was later indirectly confirmed by the spacecraft ''Galileo (spacecraft), Galileo''. The mystery of Titan's reddish haze was also solved with Sagan's help. The reddish haze was revealed to be due to complex Organic compound, organic molecules constantly raining down onto Titan's surface.
Sagan further contributed insights regarding the atmospheres of Venus and Jupiter, as well as seasonal changes on
Mars
Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...
. He also perceived global warming as a growing, man-made danger and likened it to the natural development of Venus into a hot, life-hostile planet through a kind of runaway greenhouse effect. He testified to the US Congress in 1985 that the greenhouse effect would change the earth's climate system. Sagan and his Cornell colleague Edwin Ernest Salpeter speculated about Atmosphere of Jupiter#Possibility of life, life in Jupiter's clouds, given the planet's dense atmospheric composition rich in organic molecules. He studied the observed color variations on Mars' surface and concluded that they were not seasonal or vegetational changes as most believed, but shifts in surface dust caused by dust storm#Extraterrestrial dust storms, windstorms.
Sagan is also known for his research on the possibilities of Astrobiology, extraterrestrial life, including experimental demonstration of the production of
amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...
s from basic chemicals by
radiation
In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes:
* ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...
.
He is also the 1994 recipient of the
Public Welfare Medal The Public Welfare Medal is awarded by the U.S. National Academy of Sciences "in recognition of distinguished contributions in the application of science to the public welfare." It is the most prestigious honor conferred by the academy. First award ...
, the highest award of the
National Academy of Sciences
The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...
for "distinguished contributions in the application of science to the public welfare". He was denied membership in the academy, reportedly because his media activities made him unpopular with many other scientists.
, Sagan is the most cited SETI scientist and one of the most cited planetary scientists.
''Cosmos'': popularizing science on TV
In 1980 Sagan co-wrote and narrated the award-winning 13-part PBS television series '' Cosmos: A Personal Voyage'', which became the most widely watched series in the history of American public television until 1990. The show has been seen by at least 500 million people across 60 countries. The book, ''Cosmos'', written by Sagan, was published to accompany the series.
Because of his earlier popularity as a science writer from his best-selling books, including ''The Dragons of Eden'', which won him a Pulitzer Prize in 1977, he was asked to write and narrate the show. It was targeted to a general audience of viewers, whom Sagan felt had lost interest in science, partly due to a stifled educational system.Browne, Ray Broadus. ''The Guide to United States Popular Culture'', ''Popular Press'' (2001) p. 704.
Each of the 13 episodes was created to focus on a particular subject or person, thereby demonstrating the synergy of the universe. They covered a wide range of scientific subjects including the Abiogenesis, origin of life and a perspective of humans' place on Earth.
The show won an Emmy Award, Emmy, along with a
Peabody Award
The George Foster Peabody Awards (or simply Peabody Awards or the Peabodys) program, named for the American businessman and philanthropist George Peabody, honor the most powerful, enlightening, and invigorating stories in television, radio, and ...
, and transformed Sagan from an obscure astronomer into a pop-culture icon. ''Time (magazine), Time'' magazine ran a cover story about Sagan soon after the show broadcast, referring to him as "creator, chief writer and host-narrator of the show". In 2000, "Cosmos" was released on a remastered set of DVDs.
"Billions and billions"
After ''Cosmos'' aired, Sagan became associated with the catchphrase "billions and billions," although he never actually used the phrase in the ''Cosmos'' series.#Sagan & Druyan 1997, Sagan & Druyan 1997, pp. 3–4. He rather used the term "billions ''upon'' billions."
Richard Feynman, a precursor to Sagan, was observed to have used the phrase "billions and billions" many times in his "The Feynman Lectures on Physics, red books". However, Sagan's frequent use of the word ''billions'' and distinctive delivery emphasizing the "b" (which he did intentionally, in place of more cumbersome alternatives such as "billions with a 'b, in order to distinguish the word from "millions") made him a favorite target of comic performers, including Johnny Carson, Gary Kroeger, Mike Myers, Bronson Pinchot, Penn Jillette, Harry Shearer, and others. Frank Zappa satirized the line in the song "Be in My Video", noting as well "atomic light". Sagan took this all in good humor, and his final book was entitled ''Billions and Billions'', which opened with a tongue-in-cheek discussion of this catchphrase, observing that Carson was an amateur astronomer and that Carson's comic caricature often included real science.
Sagan unit
As a humorous tribute to Sagan and his association with the catchphrase "billions and billions", a ''wikt:Sagan#Noun, sagan'' has been defined as a List of humorous units of measurement, unit of measurement equivalent to a very large number – technically at least four billion (two billion plus two billion) – of anything.
Sagan's number
Sagan's number is the number of stars in the observable universe. This number is reasonably well defined, because it is known what stars are and what the observable universe is, but its value is highly uncertain.
* In 1980, Sagan estimated it to be 10 sextillion in short scale (1022).
* In 2003, it was estimated to be 70 sextillion (7 × 1022).
* In 2010, it was estimated to be 300 sextillion (3 × 1023).
Scientific and critical thinking advocacy
Sagan's ability to convey his ideas allowed many people to understand the cosmos better—simultaneously emphasizing the value and worthiness of the human race, and the relative insignificance of the Earth in comparison to the Universe. He delivered the 1977 series of Royal Institution Christmas Lectures in London.
Sagan was a proponent of the search for extraterrestrial life. He urged the scientific community to listen with radio telescopes for signals from potential intelligent Extraterrestrial life#Indirect search, extraterrestrial life-forms. Sagan was so persuasive that by 1982 he was able to get a petition advocating SETI published in the journal ''Science (journal), Science'', signed by 70 scientists, including seven Nobel Prize winners. This signaled a tremendous increase in the respectability of a then-controversial field. Sagan also helped Frank Drake write the Arecibo message, a radio message beamed into space from the Arecibo Observatory, Arecibo radio telescope on November 16, 1974, aimed at informing potential extraterrestrials about Earth.
Sagan was chief technology officer of the professional planetary research journal ''Icarus (journal), Icarus'' for 12 years. He co-founded The Planetary Society and was a member of the SETI Institute Board of Trustees. Sagan served as Chairman of the Division for Planetary Science of the American Astronomical Society, as President of the Planetology Section of the American Geophysical Union, and as Chairman of the Astronomy Section of the American Association for the Advancement of Science (AAAS).
At the height of the Cold War, Sagan became involved in nuclear disarmament efforts by promoting hypotheses on the effects of nuclear warfare, nuclear war, when Paul Crutzen's Nuclear winter#1982, "Twilight at Noon" concept suggested that a substantial nuclear exchange could trigger a Nuclear winter#1982, nuclear twilight and upset the delicate balance of life on Earth by cooling the surface. In 1983 he was one of five authors—the "S"—in the follow-up Nuclear winter#1983, "TTAPS" model (as the research article came to be known), which contained the first use of the term "nuclear winter", which his colleague Richard P. Turco had coined. In 1984 he co-authored the book ''The Cold and the Dark: The World after Nuclear War'' and in 1990 the book ''A Path Where No Man Thought: Nuclear Winter and the End of the Arms Race'', which explains the nuclear-winter hypothesis and advocates nuclear disarmament. Sagan received a great deal of skepticism and disdain for the use of media to disseminate a very uncertain hypothesis. A personal correspondence with nuclear physicist
Edward Teller
Edward Teller ( hu, Teller Ede; January 15, 1908 – September 9, 2003) was a Hungarian-American theoretical physicist who is known colloquially as "the father of the hydrogen bomb" (see the Teller–Ulam design), although he did not care fo ...
around 1983 began amicably, with Teller expressing support for continued research to ascertain the credibility of the winter hypothesis. However, Sagan and Teller's correspondence would ultimately result in Teller writing: "A propagandist is one who uses incomplete information to produce maximum persuasion. I can compliment you on being, indeed, an excellent propagandist, remembering that a propagandist is the better the less he appears to be one". Biographers of Sagan would also comment that from a scientific viewpoint, nuclear winter was a low point for Sagan, although, politically speaking, it popularized his image amongst the public.
The adult Sagan remained a fan of science fiction, although disliking stories that were not realistic (such as ignoring the inverse-square law) or, he said, did not include "thoughtful pursuit of alternative futures". He wrote books to popularize science, such as ''Cosmos'', which reflected and expanded upon some of the themes of ''A Personal Voyage'' and became the best-selling science book ever published in English; ''
The Dragons of Eden
''The Dragons of Eden: Speculations on the Evolution of Human Intelligence'' is a 1977 book by Carl Sagan, in which the author combines the fields of anthropology, evolutionary biology, psychology, and computer science to give a perspective on ho ...
: Speculations on the Evolution of Human Intelligence'', which won a Pulitzer Prize; and ''Broca's Brain (book), Broca's Brain: Reflections on the Romance of Science''. Sagan also wrote the best-selling science fiction novel ''Contact'' in 1985, based on a film treatment he wrote with his wife, Ann Druyan, in 1979, but he did not live to see the book's 1997 Contact (1997 American film), motion-picture adaptation, which starred Jodie Foster and won the 1998
Hugo Award
The Hugo Award is an annual literary award for the best science fiction or fantasy works and achievements of the previous year, given at the World Science Fiction Convention and chosen by its members. The Hugo is widely considered the premier a ...
for Best Dramatic Presentation.
Sagan wrote a sequel to ''Cosmos'', ''Pale Blue Dot (book), Pale Blue Dot: A Vision of the Human Future in Space'', which was selected as a notable book of 1995 by ''The New York Times''. He appeared on PBS's ''Charlie Rose (TV series), Charlie Rose'' program in January 1995. Sagan also wrote the introduction for Stephen Hawking's bestseller ''A Brief History of Time''. Sagan was also known for his popularization of science, his efforts to increase scientific understanding among the general public, and his positions in favor of scientific skepticism and against pseudoscience, such as his Debunker, debunking of the Betty and Barney Hill abduction. To mark the tenth anniversary of Sagan's death, David Morrison (astrophysicist), David Morrison, a former student of Sagan, recalled "Sagan's immense contributions to planetary research, the public understanding of science, and the skeptical movement" in ''Skeptical Inquirer''.
Following Saddam Hussein's threats to light Kuwait's oil wells on fire in response to any physical challenge to Iraqi control of the oil assets, Sagan together with his "TTAPS" colleagues and Paul Crutzen, warned in January 1991 in ''The Baltimore Sun'' and ''Wilmington Morning Star'' newspapers that if the fires were left to burn over a period of several months, enough smoke from the 600 or so 1991 Kuwaiti oil fires "might get so high as to disrupt agriculture in much of South Asia ..." and that this possibility should "affect the war plans"; these claims were also the subject of a televised debate between Sagan and physicist Fred Singer on January 22, aired on the ABC News program ''Nightline (US news program), Nightline''. In the televised debate, Sagan argued that the effects of the smoke would be similar to the effects of a nuclear winter, with Singer arguing to the contrary. After the debate, the fires burnt for many months before extinguishing efforts were complete. The results of the smoke did not produce continental-sized cooling. Sagan later conceded in ''The Demon-Haunted World'' that the prediction did not turn out to be correct: "it ''was'' pitch black at noon and temperatures dropped 4–6 °C over the Persian Gulf, but not much smoke reached stratospheric altitudes and Asia was spared".
In his later years Sagan advocated the creation of an organized search for asteroids/near-Earth objects (NEOs) that might impact the Earth but to forestall or postpone developing the technological methods that would be needed to defend against them. He argued that all of the numerous methods proposed to asteroid impact avoidance, alter the orbit of an asteroid, including the employment of nuclear weapon design, nuclear detonations, created a Asteroid impact avoidance#Deflection technology concerns, deflection dilemma: if the ability to deflect an asteroid away from the Earth exists, then one would also have the ability to divert a non-threatening object towards Earth, creating an immensely destructive weapon. In a 1994 paper he co-authored, he ridiculed a 3-day long "Asteroid impact avoidance#Nuclear explosive device, Near-Earth Object Interception Workshop" held by Los Alamos National Laboratory (LANL) in 1993 that did not, "even in passing" state that such interception and deflection technologies could have these "ancillary dangers".
Sagan remained hopeful that the natural NEO impact threat and the intrinsically double-edged essence of the methods to prevent these threats would serve as a "new and potent motivation to maturing international relations". Later acknowledging that, with sufficient international oversight, in the future a "work our way up" approach to implementing nuclear explosive deflection methods could be fielded, and when sufficient knowledge was gained, to use them to aid in mining asteroids. His interest in the use of nuclear detonations in space grew out of his work in 1958 for the Armour Research Foundation's
Project A119
Project A119, also known as A Study of Lunar Research Flights, was a top-secret plan developed in 1958 by the United States Air Force. The aim of the project was to detonate a nuclear bomb on the Moon, which would help in answering some of th ...
, concerning the possibility of detonating a nuclear device on the lunar surface.
Sagan was a critic of Plato, having said of the ancient Greek philosopher: "Science and mathematics were to be removed from the hands of the merchants and the artisans. This tendency found its most effective advocate in a follower of Pythagoras named Plato" and
In 1995 (as part of his book ''
The Demon-Haunted World
''The Demon-Haunted World: Science as a Candle in the Dark'' is a 1995 book by the astrophysicist Carl Sagan and co-authored by Ann Druyan, in which the authors aim to explain the scientific method to laypeople and to encourage people to learn c ...
'') Sagan popularized a set of tools for skeptical thinking called the The Demon-Haunted World#Baloney, "baloney detection kit", a phrase first coined by Arthur Felberbaum, a friend of his wife Ann Druyan.
Popularizing science
Speaking about his activities in popularizing science, Sagan said that there were at least two reasons for scientists to share the purposes of science and its contemporary state. Simple self-interest was one: much of the funding for science came from the public, and the public therefore had the right to know how the money was being spent. If scientists increased public admiration for science, there was a good chance of having more public supporters. The other reason was the excitement of communicating one's own excitement about science to others.
Following the success of ''Cosmos'', Sagan set up his own publishing firm, Cosmos Store, to publish science books for the general public. It was not successful.
Criticisms
While Sagan was widely adored by the general public, his reputation in the scientific community was more polarized. Critics sometimes characterized his work as fanciful, non-rigorous, and self-aggrandizing, and others complained in his later years that he neglected his role as a faculty member to foster his celebrity status.
One of Sagan's harshest critics,
Harold Urey
Harold Clayton Urey ( ; April 29, 1893 – January 5, 1981) was an American physical chemist whose pioneering work on isotopes earned him the Nobel Prize in Chemistry in 1934 for the discovery of deuterium. He played a significant role in the d ...
, felt that Sagan was getting too much publicity for a scientist and was treating some scientific theories too casually.Davidson, p. 203. Urey and Sagan were said to have different philosophies of science, according to Davidson. While Urey was an "old-time empiricist" who avoided theorizing about the unknown, Sagan was by contrast willing to speculate openly about such matters. Fred Whipple wanted Harvard to keep Sagan there, but learned that because Urey was a Nobel laureate, his opinion was an important factor in Harvard denying Sagan tenure.
Sagan's Harvard friend Lester Grinspoon also stated: "I know Harvard well enough to know there are people there who certainly do not like people who are outspoken." Grinspoon added:
Some, like Urey, later came to realize that Sagan's popular brand of scientific advocacy was beneficial to the science as a whole.Davidson, p. 297. Urey especially liked Sagan's 1977 book ''
The Dragons of Eden
''The Dragons of Eden: Speculations on the Evolution of Human Intelligence'' is a 1977 book by Carl Sagan, in which the author combines the fields of anthropology, evolutionary biology, psychology, and computer science to give a perspective on ho ...
'' and wrote Sagan with his opinion: "I like it very much and am amazed that someone like you has such an intimate knowledge of the various features of the problem... I congratulate you... You are a man of many talents."
Sagan was accused of borrowing some ideas of others for his own benefit and countered these claims by explaining that the misappropriation was an unfortunate side effect of his role as a science communicator and explainer, and that he attempted to give proper credit whenever possible.
Social concerns
Sagan believed that the Drake equation, on substitution of reasonable estimates, suggested that a large number of extraterrestrial civilizations would form, but that the lack of evidence of such civilizations highlighted by the Fermi paradox suggests Technology, technological civilizations tend to self-destruct. This stimulated his interest in identifying and publicizing ways that humanity could destroy itself, with the hope of avoiding such a Risks to civilization, humans, and planet Earth, cataclysm and eventually becoming a spacefaring species. Sagan's deep concern regarding the potential destruction of Risks to civilization, humans, and planet Earth, human civilization in a nuclear holocaust was conveyed in a memorable cinematic sequence in the final episode of ''Cosmos'', called "Who Speaks for Earth?" Sagan had already resigned from the United States Air Force Scientific Advisory Board, Air Force Scientific Advisory Board's UFO investigating Condon Committee and voluntarily surrendered his Security clearance#Top Secret, top-secret clearance in protest over the Vietnam War. Following his marriage to his third wife (novelist Ann Druyan) in June 1981, Sagan became more politically active—particularly in opposing escalation of the nuclear arms race under President Ronald Reagan.
In March 1983, Reagan announced the Strategic Defense Initiative—a multibillion-dollar project to develop a comprehensive missile defense, defense against attack by Nuclear weapons delivery#Ballistic missile, nuclear missiles, which was quickly dubbed the "Star Wars" program. Sagan spoke out against the project, arguing that it was technically impossible to develop a system with the level of perfection required, and far more expensive to build such a system than it would be for an enemy to defeat it through Decoy#Military decoy, decoys and other means—and that its construction would seriously destabilize the "nuclear balance" between the United States and the Soviet Union, making further progress toward nuclear disarmament impossible.
When Soviet leader Mikhail Gorbachev declared a unilateral moratorium on the Nuclear weapons testing, testing of nuclear weapons, which would begin on August 6, 1985—the 40th anniversary of the Nuclear weapon#Fission weapons, atomic bombing of Atomic bombings of Hiroshima and Nagasaki, Hiroshima—the Reagan administration dismissed the dramatic move as nothing more than propaganda and refused to follow suit. In response, US Anti-nuclear movement, anti-nuclear and peace activists staged a series of protest actions at the Nevada National Security Site, Nevada Test Site, beginning on Easter Sunday in 1986 and continuing through 1987. Hundreds of people in the "Nevada Desert Experience" group were arrested, including Sagan, who was arrested on two separate occasions as he climbed over a chain-link fence at the test site during the underground Operation Charioteer and Operation Musketeer (Nuclear test), United States's Musketeer nuclear test series of detonations.
Sagan was also a vocal advocate of the controversial notion of testosterone poisoning, arguing in 1992 that human males could become gripped by an "unusually severe [case of] testosterone poisoning" and this could compel them to become genocidal. In his review of Moondance magazine writer Daniela Gioseffi's 1990 book ''Women on War'', he argues that females are the only half of humanity "untainted by testosterone poisoning". One chapter of his 1993 book '' Shadows of Forgotten Ancestors'' is dedicated to testosterone and its alleged poisonous effects.
In 1989, Carl Sagan was interviewed by Ted Turner whether he believed in socialism and responded that: "I'm not sure what a socialist is. But I believe the government has a responsibility to care for the people... I'm talking about making the people self-reliant."
Personal life and beliefs
Sagan was married three times. In 1957, he married biologist Lynn Margulis. The couple had two children, Jeremy and Dorion Sagan; their marriage ended in 1964. Sagan married artist Linda Salzman Sagan, Linda Salzman in 1968 and they had a child together, Nick Sagan, and divorced in 1981. During these marriages, Carl Sagan focused heavily on his career, a factor which may have contributed to Sagan's first divorce. In 1981, Sagan married author Ann Druyan and they later had two children, Alexandra (known as Sasha Sagan, Sasha) and Samuel Sagan. Carl Sagan and Druyan remained married until his death in 1996.
While teaching at Cornell, he lived in an 900 Stewart Avenue (Ithaca, New York), Egyptian revival house in Ithaca perched on the edge of a cliff that had formerly been the headquarters of a Cornell secret society. While there he drove a red Porsche 911 (classic)#2.2-litre / C and D series (1969–1971), Porsche 911 Targa and an orange 1970 Porsche 914 with the license plate PHOBOS.
In 1994, engineers at Apple Inc., Apple Computer code-named the Power Macintosh 7100 "Carl Sagan" in the hope that Apple would make "billions and billions" with the sale of the PowerMac 7100. The name was only used internally, but Sagan was concerned that it would become a product endorsement and sent Apple a cease-and-desist letter. Apple complied, but engineers retaliated by changing the internal codename to "BHA" for "Notable litigation of Apple Computer#Libel dispute with Carl Sagan, Butt-Head Astronomer".Poundstone 1999, p. 364 Sagan then sued Apple for libel in federal court. The court granted Apple's motion to dismiss Sagan's claims and opined in Obiter dictum, dicta that a reader aware of the context would understand Apple was "clearly attempting to retaliate in a humorous and satirical way", and that "It strains reason to conclude that Defendant was attempting to criticize Plaintiff's reputation or competency as an astronomer. One does not seriously attack the expertise of a scientist using the undefined phrase 'butt-head'." Sagan then sued for Apple's original use of his name and likeness, but again lost.Poundstone 1999, p. 374 Sagan appealed the ruling. In November 1995, an out-of-court settlement was reached and Apple's office of trademarks and patents released a conciliatory statement that "Apple has always had great respect for Dr. Sagan. It was never Apple's intention to cause Dr. Sagan or his family any embarrassment or concern."Poundstone 1999, pp. 374–375 Apple's third and final code name for the project was "LAW", short for "Lawyers are Wimps".
In 2019, Carl Sagan's daughter Sasha Sagan released ''For Small Creatures Such as We: Rituals for Finding Meaning in our Unlikely World'', which depicts life with her parents and her father's death when she was fourteen. Building on a theme in her father's work, Sasha Sagan argues in ''For Small Creatures Such as We'' that skepticism does not imply pessimism.
Sagan was acquainted with the science fiction fandom through his friendship with Isaac Asimov, and he spoke at the Nebula Awards ceremony in 1969. Asimov described Sagan as one of only two people he ever met whose intellect surpassed his own, the other being computer scientist and artificial intelligence expert Marvin Minsky.
Naturalism
Sagan wrote frequently about religion and the relationship between religion and science, expressing his skepticism about the conventional conceptualization of God as a sapient being. For example:
In another description of his view on the concept of God, Sagan wrote:
On atheism, Sagan commented in 1981:
Sagan also commented on Christianity and the Jefferson Bible, stating "My long-time view about Christianity is that it represents an amalgam of two seemingly immiscible parts, the religion of Jesus and the religion of Paul the Apostle, Paul. Thomas Jefferson attempted to excise the Pauline parts of the New Testament. There wasn't much left when he was done, but it was an inspiring document."
Regarding spirituality and its relationship with science, Sagan stated:
An environmental appeal, "Preserving and Cherishing the Earth", primarily written and signed by Sagan, with other noted scientists and religious leaders in January 1990, stated that "The historical record makes clear that religious teaching, example, and leadership are powerfully able to influence personal conduct and commitment... Thus, there is a vital role for religion and science."
In reply to a question in 1996 about his religious beliefs, Sagan answered, "I'm agnostic." Sagan maintained that the idea of a creator God of the Universe was difficult to prove or disprove and that the only conceivable scientific discovery that could challenge it would be an infinitely old universe. Sagan's views on religion have been interpreted as a form of pantheism comparable to Einstein's belief in Spinozism, Spinoza's God. His son, Dorion Sagan said, "My father believed in the God of Spinoza and Einstein, God not behind nature but as nature, equivalent to it." His last wife, Ann Druyan, stated:
In 2006, Ann Druyan edited Sagan's 1985 Glasgow ''Gifford Lectures in Natural Theology'' into a book, ''The Varieties of Scientific Experience: A Personal View of the Search for God'', in which he elaborates on his views of divinity in the nature, natural world.
Sagan is also widely regarded as a freethought, freethinker or skepticism, skeptic; one of his most famous quotations, in ''Cosmos'', was, "Extraordinary claims require extraordinary evidence" (called the "Sagan standard" by some). This was based on a nearly identical statement by fellow founder of the Committee for Skeptical Inquiry, Committee for the Scientific Investigation of Claims of the Paranormal, Marcello Truzzi, "An extraordinary claim requires extraordinary proof." This idea had been earlier aphorized in Théodore Flournoy's work ''From India to the Planet Mars'' (1899) from a longer quote by Pierre-Simon Laplace (1749–1827), a French mathematician and astronomer, as the Principle of Laplace: "The weight of the evidence should be proportioned to the strangeness of the facts."
Late in his life, Sagan's books elaborated on his naturalism (philosophy), naturalistic view of the world. In ''The Demon-Haunted World'', he presented tools for testing arguments and detecting fallacious or fraudulent ones, essentially advocating wide use of critical thinking and the scientific method. The compilation ''Billions and Billions: Thoughts on Life and Death at the Brink of the Millennium'', published in 1997 after Sagan's death, contains essays written by Sagan, such as his views on abortion, as well as an account by his widow, Ann Druyan, of his death in relation to his having been an agnostic and freethinker.
Sagan warned against humans' tendency towards anthropocentrism. He was the faculty adviser for the Cornell Students for the Ethical Treatment of Animals. In the ''Cosmos'' chapter "Blues For a Red Planet", Sagan wrote, "If there is life on Mars, I believe we should do nothing with Mars. Mars then belongs to the Martians, even if the Martians are only microbes."
Marijuana advocacy
Sagan was a user and advocate of cannabis (drug), marijuana. Under the pseudonym "Mr. X", he contributed an essay about smoking cannabis to the 1971 book ''Marihuana Reconsidered''. The essay explained that marijuana use had helped to inspire some of Sagan's works and enhance sensual and intellectual experiences. After Sagan's death, his friend Lester Grinspoon disclosed this information to Sagan's biographer, Keay Davidson. The publishing of the biography, ''Carl Sagan: A Life'', in 1999 brought media attention to this aspect of Sagan's life. Not long after his death, his widow Ann Druyan went on to preside over the board of directors of the National Organization for the Reform of Marijuana Laws (NORML), a non-profit organization dedicated to reforming cannabis laws.
UFOs
In 1947, the year that inaugurated the "
flying saucer
A flying saucer (also referred to as "a flying disc") is a descriptive term for a type of flying craft having a disc or saucer-shaped body, commonly used generically to refer to an anomalous flying object. The term was coined in 1947 but has g ...
" fad, craze, the young Sagan suspected the "discs" might be alien spaceships.
Sagan's interest in Unidentified flying object, UFO reports prompted him on August 3, 1952, to write a letter to U.S. Secretary of State Dean Acheson to ask how the United States would respond if flying saucers turned out to be extraterrestrial. He later had several conversations on the subject in 1964 with Jacques Vallée. Though quite skeptical of any extraordinary answer to the UFO question, Sagan thought scientists should study the phenomenon, at least because there was widespread public interest in UFO reports.
Stuart Appelle notes that Sagan "wrote frequently on what he perceived as the logical and empiricism, empirical fallacy, fallacies regarding UFOs and the Alien abduction, abduction experience. Sagan rejected an extraterrestrial hypothesis, extraterrestrial explanation for the phenomenon but felt there were both empirical and pedagogy, pedagogical benefits for examining UFO reports and that the subject was, therefore, a legitimate topic of study."
In 1966 Sagan was a member of the Ad Hoc Committee to Review Project Blue Book, the United States Air Force, U.S. Air Force's UFO investigation project. The committee concluded Blue Book had been lacking as a scientific study, and recommended a university-based project to give the UFO phenomenon closer scientific scrutiny. The result was the Condon Committee (1966–68), led by physicist Edward Condon, and in their final report they formally concluded that UFOs, regardless of what any of them actually were, did not behave in a manner consistent with a threat to national security.
Sociologist Ron Westrum writes that "The high point of Sagan's treatment of the UFO question was the AAAS' symposium in 1969. A wide range of educated opinions on the subject were offered by participants, including not only proponents such as James E. McDonald, James McDonald and J. Allen Hynek but also skeptics like astronomers William Kenneth Hartmann, William Hartmann and Donald Howard Menzel, Donald Menzel. The roster of speakers was balanced, and it is to Sagan's credit that this event was presented in spite of pressure from Edward Condon." With physicist Thornton Page, Sagan edited the lectures and discussions given at the symposium; these were published in 1972 as ''UFO's: A Scientific Debate''. Some of Sagan's many books examine UFOs (as did one episode of ''Cosmos'') and he claimed a religious undercurrent to the phenomenon.
Sagan again revealed his views on interstellar travel in his 1980 ''Cosmos'' series. In one of his last written works, Sagan argued that the chances of extraterrestrial spacecraft visiting Earth are vanishingly small. However, Sagan did think it plausible that Cold War concerns contributed to governments misleading their citizens about UFOs, and wrote that "some UFO reports and analyses, and perhaps voluminous files, have been made inaccessible to the public which pays the bills ... It's time for the files to be declassified and made generally available." He cautioned against jumping to conclusions about suppressed UFO data and stressed that there was no strong evidence that aliens were visiting the Earth either in the past or present.
Sagan briefly served as an adviser on Stanley Kubrick's film ''2001: A Space Odyssey (film), 2001: A Space Odyssey''. Sagan proposed that the film suggest, rather than depict, extraterrestrial superintelligence.
"Sagan's paradox"
Sagan's contribution to the 1969 AAAS symposium was an attack on the belief that UFOs are piloted by extraterrestrial beings. Applying several logical assumptions (see Drake equation), Sagan calculated the possible number of advanced civilizations capable of interstellar travel to be about one million. He projected that any civilization wishing to check on all the others on a regular basis of, say, once a year would have to launch 10,000 spacecraft annually. Not only does that seem like an unreasonable number of launchings, but it would take all the material in one percent of the universe's stars to produce all the spaceships needed for all the civilizations to seek each other out.
To argue that the Earth was being chosen for regular visitations, Sagan said, one would have to assume that the planet is somehow unique, and that assumption "goes exactly against the idea that there are lots of civilizations around. Because if there are then our sort of civilization must be pretty common. And if we're not pretty common then there aren't going to be many civilizations advanced enough to send visitors".
This argument, which some called Sagan's paradox, helped to establish a new school of thought, namely the belief that extraterrestrial life exists, but it has nothing to do with UFOs. The new belief had a salutary effect on UFO studies. It helped separate researchers who wanted to distinguish UFOs from those who wanted to identify their pilots and it gave scientists opportunities to search the universe for intelligent life unencumbered by the stigma associated with UFOs.
Death
After having Myelodysplastic syndrome, myelodysplasia for two years and receiving three Hematopoietic stem cell transplantation, bone marrow transplants from his sister, Sagan died from
pneumonia
Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity ...
at the age of 62 at the Fred Hutchinson Cancer Research Center in Seattle, Washington, on December 20, 1996. His burial took place at Lake View Cemetery (Ithaca, New York), Lake View Cemetery in Ithaca, New York, Ithaca, New York.
Awards and honors
* Annual Award for Television Excellence—1981—Ohio State University—PBS series '' Cosmos: A Personal Voyage''
* Apollo Achievement Award—NASA, National Aeronautics and Space Administration
*
NASA Distinguished Public Service Medal
The NASA Distinguished Public Service Medal is an award similar to the NASA Distinguished Service Medal, but awarded to non-government personnel. This is the highest honor NASA awards to anyone who was not a government employee when the service ...
—National Aeronautics and Space Administration (1977)
* Emmy—Outstanding Individual Achievement—1981—PBS series ''Cosmos: A Personal Voyage''
* Emmy—Primetime Emmy Award, Outstanding Informational Series—1981—PBS series ''Cosmos: A Personal Voyage''
* Fellow of the American Physical Society–1989
* NASA Exceptional Achievement Medal, Exceptional Scientific Achievement Medal—National Aeronautics and Space Administration
* Helen Caldicott Leadership Award – Awarded by Women's Action for New Directions, Women's Action for Nuclear Disarmament
*
Hugo Award
The Hugo Award is an annual literary award for the best science fiction or fantasy works and achievements of the previous year, given at the World Science Fiction Convention and chosen by its members. The Hugo is widely considered the premier a ...
—1981—Hugo Award for Best Dramatic Presentation, Best Dramatic Presentation—''Cosmos: A Personal Voyage''
* Hugo Award—1981—Hugo Award for Best Related Work, Best Related Non-Fiction Book—''Cosmos''
* Hugo Award—1998—Best Dramatic Presentation—''Contact''
* American Humanist Association#AHA's Humanists of the Year, Humanist of the Year—1981—Awarded by the American Humanist Association
* American Philosophical Society—1995—Elected to membership.
* In Praise of Reason Award—1987—Committee for Skeptical Inquiry
* Isaac Asimov Awards, Isaac Asimov Award—1994—Committee for Skeptical Inquiry
* John F. Kennedy Astronautics Award—1982—American Astronautical Society
* Special non-fiction John W. Campbell Memorial Award for Best Science Fiction Novel, Campbell Memorial Award—1974—''The Cosmic Connection: An Extraterrestrial Perspective''
* Joseph Priestley Award—"For distinguished contributions to the welfare of mankind"
* Klumpke-Roberts Award of the Astronomical Society of the Pacific—1974
* Golden Plate Award of the Academy of Achievement, American Academy of Achievement—1975
* Konstantin Tsiolkovsky Medal—Awarded by the Soviet Cosmonauts Federation
* Locus Award 1986—''Contact''
* Lowell Thomas Award—The Explorers Club—75th Anniversary
* Masursky Award—American Astronomical Society
* Miller Research Fellowship—Miller Institute (1960–1962)
* Oersted Medal—1990—American Association of Physics Teachers
*
Peabody Award
The George Foster Peabody Awards (or simply Peabody Awards or the Peabodys) program, named for the American businessman and philanthropist George Peabody, honor the most powerful, enlightening, and invigorating stories in television, radio, and ...
—1980—PBS series ''Cosmos: A Personal Voyage''
* Le Prix Galabert d'astronautique—International Astronautical Federation (IAF)
*
Public Welfare Medal The Public Welfare Medal is awarded by the U.S. National Academy of Sciences "in recognition of distinguished contributions in the application of science to the public welfare." It is the most prestigious honor conferred by the academy. First award ...
—1994—
National Academy of Sciences
The National Academy of Sciences (NAS) is a United States nonprofit, non-governmental organization. NAS is part of the National Academies of Sciences, Engineering, and Medicine, along with the National Academy of Engineering (NAE) and the Nati ...
*
Pulitzer Prize for General Non-Fiction
The Pulitzer Prize for General Nonfiction is one of the seven American Pulitzer Prizes that are awarded annually for the "Letters, Drama, and Music" category. The award is given to a nonfiction book written by an American author and published duri ...
—1978—''
The Dragons of Eden
''The Dragons of Eden: Speculations on the Evolution of Human Intelligence'' is a 1977 book by Carl Sagan, in which the author combines the fields of anthropology, evolutionary biology, psychology, and computer science to give a perspective on ho ...
''
* Science Fiction Chronicle Award—1998—Dramatic Presentation—''Contact''
* UCLA Medal–1991
* Inductee to International Space Hall of Fame in 2004
* Named the "The Greatest American, 99th Greatest American" on June 5, 2005, ''Greatest American'' Television program#Seasons/series, television series on the Discovery Channel
* Named an honorary member of the Demosthenian Literary Society on November 10, 2011
* New Jersey Hall of Fame—2009—Inductee.
*Committee for Skeptical Inquiry (CSI) Pantheon of Skeptics—April 2011—Inductee
* Grand-Cross of the Order of Saint James of the Sword, Portugal (November 23, 1998)
*Honorary Doctor of Science (Sc.D.) degree from Whittier College in 1978.
Posthumous recognition
The 1997 film ''Contact (1997 American film), Contact'', based on Sagan's only novel of the same name and finished after his death, ends with the dedication "For Carl". His photo can also be seen in the film.
In 1997, the Sagan Planet Walk was opened in Ithaca, New York. It is a walking-scale model of the Solar System, extending 1.2 km from the center of The Commons in downtown Ithaca to the Sciencenter, a hands-on museum. The exhibition was created in memory of Carl Sagan, who was an Ithaca resident and Cornell Professor. Professor Sagan had been a founding member of the museum's advisory board.
The landing site of the unmanned ''Mars Pathfinder'' spacecraft was renamed the Mars Pathfinder#End of mission, Carl Sagan Memorial Station on July 5, 1997.
Asteroid 2709 Sagan is named in his honor, as is the Carl Sagan Institute for the search of habitable planets.
Sagan's son, Nick Sagan, wrote several episodes in the ''Star Trek'' franchise. In an episode of ''Star Trek: Enterprise'' entitled "Terra Prime", a quick shot is shown of the relic Rover (space exploration), rover ''Mars Pathfinder#Sojourner rover, Sojourner'', part of the ''Mars Pathfinder'' mission, placed by a historical marker at Mars Pathfinder, Carl Sagan Memorial Station on the Martian surface. The marker displays a quote from Sagan: "Whatever the reason you're on Mars, I'm glad you're there, and I wish I was with you." Sagan's student Steve Squyres led the team that landed the rovers ''Spirit (rover), Spirit'' and ''Opportunity (rover), Opportunity'' successfully on Mars in 2004.
On November 9, 2001, on what would have been Sagan's 67th birthday, the Ames Research Center dedicated the site for the Carl Sagan Center for the Study of Life in the Cosmos. "Carl was an incredible visionary, and now his legacy can be preserved and advanced by a 21st century research and education laboratory committed to enhancing our understanding of life in the universe and furthering the cause of space exploration for all time", said NASA Administrator Daniel Goldin. Ann Druyan was at the center as it opened its doors on October 22, 2006.
Sagan has at least three awards named in his honor:
* The Carl Sagan Memorial Award presented jointly since 1997 by the American Astronomical Society and The Planetary Society,
* The Carl Sagan Medal for Excellence in Public Communication in Planetary Science presented since 1998 by the American Astronomical Society's Division for Planetary Sciences (AAS/DPS) for outstanding communication by an active planetary scientist to the general public—Carl Sagan was one of the original organizing committee members of the DPS, and
* The Carl Sagan Award for Public Understanding of Science presented by the Council of Scientific Society presidents (CSSP)—Sagan was the first recipient of the CSSP award in 1993.
August 2007 the Independent Investigations Group (IIG) awarded Sagan posthumously a Lifetime Achievement Award. This honor has also been awarded to Harry Houdini and James Randi.
In September 2008, a musical compositor Benn Jordan released his album Benn Jordan#As Benn Jordan, ''Pale Blue Dot'' as a tribute to Carl Sagan's life.
Beginning in 2009, a musical project known as Symphony of Science sampled several excerpts of Sagan from his series ''Cosmos'' and remixed them to electronic music. To date, the videos have received over 21 million views worldwide on YouTube.
The 2014 Swedish science fiction short film ''Wanderers (short film), Wanderers'' uses excerpts of Sagan's narration of his book ''Pale Blue Dot'', played over digitally-created visuals of humanity's possible future expansion into outer space.
In February 2015, the Finnish-based symphonic metal band Nightwish released the song "Sagan" as a non-album bonus track for their single "Élan (song), Élan". The song, written by the band's songwriter/composer/keyboardist Tuomas Holopainen, is an homage to the life and work of the late Carl Sagan.
In August 2015, it was announced that a biopic of Sagan's life was being planned by Warner Bros.
On October 21, 2019, the Carl Sagan and Ann Druyan Theater was opened at the Center for Inquiry West in Los Angeles.
In 2022, Sagan was posthumously awarded the Future of Life Award "for reducing the risk of nuclear war by developing and popularizing the science of nuclear winter." The honor, shared by seven other recipients involved in nuclear winter research, was accepted by his widow, Ann Druyan.
"A man whose time has come" Interview with Carl Sagan by Ian Ridpath, ''New Scientist'', July 4, 1974
*
*
"Carl Sagan's Life and Legacy as Scientist, Teacher, and Skeptic" by David Morrison, Committee for Skeptical Inquiry
FBI Records: The Vault – Carl Sagan at fbi.gov
"NASA Technical Reports Server (NTRS) 19630011050: Direct Contact Among Galactic Civilizations by Relativistic Interstellar Spaceflight" Carl Sagan, when he was at Stanford University, in 1962, produced a controversial paper funded by a NASA research grant that concludes ancient alien intervention may have sparked human civilization.
Scientist of the Day-Carl Sagan at Linda Hall Library
* Carl Saga demonstrates how Eratosthenes determined that the Earth was round and the approximate circumference of the earth
{{DEFAULTSORT:Sagan, Carl
Carl Sagan,
1934 births
1996 deaths
20th-century American astronomers
20th-century American male writers
20th-century American novelists
20th-century naturalists
American agnostics
American anti–nuclear weapons activists
American anti–Vietnam War activists
American astrophysicists
American cannabis activists
American cosmologists
American humanists
American male non-fiction writers
American male novelists
American naturalists
American nature writers
American pacifists
American people of Russian-Jewish descent
American people of Ukrainian-Jewish descent
American science fiction writers
American science writers
American skeptics
American social commentators
American UFO writers
Articles containing video clips
Astrobiologists
Astrochemists
Burials in New York (state)
Cornell University faculty
Critics of alternative medicine
Critics of creationism
Critics of parapsychology
Critics of religions
Cultural critics
Deaths from myelodysplastic syndrome
Deaths from pneumonia in Washington (state)
Fellows of the American Physical Society
Grand Crosses of the Order of Saint James of the Sword
Harvard University faculty
Hugo Award-winning writers
Interstellar messages
Jewish activists
Jewish agnostics
Jewish American scientists
Jewish astronomers
Jewish skeptics
Members of the American Philosophical Society
Novelists from New York (state)
Pantheists
People associated with the American Museum of Natural History
People from Bensonhurst, Brooklyn
Planetary scientists
Presidents of The Planetary Society
Pulitzer Prize for General Non-Fiction winners
Rahway High School alumni
Sagan family
Science communicators
Scientists from New York (state)
Search for extraterrestrial intelligence
Secular humanists
Social critics
Space advocates
Spinozists
University of California, Berkeley fellows
University of Chicago alumni
Writers about religion and science
Writers from Brooklyn