A Religious cosmology (also mythological cosmology) is a way of explaining the origin, the history and the evolution of the cosmos or universe based on the religious mythology of a specific tradition. Religious cosmologies usually include an act or process of creation by a creator deity or a larger pantheon.

Buddhism[link]

In Buddhism, the universe comes into existence dependent upon the actions (karma) of its inhabitants. Buddhists posit neither an ultimate beginning or final end to the universe, but see the universe as something in flux, passing in and out of existence, parallel to an infinite number of other universes doing the same thing.

The Buddhist universe consists of a large number of worlds which correspond to different mental states, including passive states of trance, passionless states of purity, and lower states of desire, anger, and fear. The beings in these worlds are all coming into existence or being born, and passing out of existence into other states, or dying. A world comes into existence when the first being in it is born, and ceases to exist, as such, when the last being in it dies. The universe of these worlds also is born and dies, with the death of the last being preceding a universal conflagration that destroys the physical structure of the worlds; then, after an interval, beings begin to be born again and the universe is once again built up. Other universes, however, also exist, and there are higher planes of existence which are never destroyed, though beings that live in them also come into and pass out of existence.

As well as a model of universal origins and destruction, Buddhist cosmology also functions as a model of the mind, with its thoughts coming into existence based on preceding thoughts, and being transformed into other thoughts and other states.

Hebrew Bible[link]

The main Judeo-Christian religious text, the Bible, opens with a story of creation. The first two chapters of the Book of Genesis describe the creation of heaven and earth by God (called both Elohim and Yhvh) in six successive days.

• First day: God creates light ("Let there be light!")^[Gen 1:3]—the first divine command. The light is divided from the darkness, and "day" and "night" are named.
• Second day: God creates a firmament ("Let a firmament be...!")^{[Gen 1:6–7]}—the second command—to divide the waters above from the waters below. The firmament is named "heaven" (shamayim).
• Third day: God commands the waters below to be gathered together in one place, and dry land to appear (the third command).^{[Gen 1:9–10]} "earth" and "sea" are named. God commands the earth to bring forth grass, plants, and fruit-bearing trees (the fourth command).
• Fourth day: God creates lights in the firmament (the fifth command)^{[Gen 1:14–15]} to separate light from darkness and to mark days, seasons and years. Two great lights are made and the stars.
• Fifth day: God commands the sea to "teem with living creatures", and birds to fly across the heavens (sixth command)^{[Gen 1:20–21]} He creates birds and sea creatures, and commands them to be fruitful and multiply.
• Sixth day: God commands the land to bring forth living creatures (seventh command); He makes wild beasts, livestock and "every thing that creepeth upon the earth".^{[Gen 1:24–25]} He then creates humanity in His "image" and "likeness" (eighth command).^{[Gen 1:26–28]} They are told to "be fruitful, and multiply, and fill the earth, and subdue it." The totality of creation is described by God as "very good."
• Seventh day: God, having completed the heavens and the earth, rests from His work, and blesses and sanctifies the seventh day.^[Gen 2:2]

Christianity[link]

It is a tenet of Christian faith (Roman Catholic, Orthodox and Protestant) that God is the creator of all things from nothing, and has made human beings in the Image of God, who by direct inference is also the source of the human soul. In Chalcedonian Christology, Jesus is the Word of God, which was in the beginning and, thus, is uncreated, and hence is God, and consequently identical with the Creator of the world ex nihilo.

The New Testament claims that God created everything by the eternal Word, Jesus Christ his beloved Son. In him:

"all things were created, in heaven and on earth.. . all things were created through him and for him. He is before all things, and in him all things hold together.^[1]

Mormon[link]

Mormon cosmology draws from Biblical cosmology, but has many unique elements provided by Latter Day Saint movement founder Joseph Smith, Jr.

According to Mormon cosmology, there was a pre-existence, better described as a pre-mortal life, in which human spirits were literal children of heavenly parents.^[2] Though their spirits were created, the essential "intelligence" of these spirits is considered eternal, and without beginning. During this pre-existence, two plans were said to have been presented, one championed by Lucifer (Satan) that would have involved loss of moral agency, and another championed by God the Father. When his plan was not accepted, Lucifer is said to have rebelled and taken a third of the hosts of heaven with him to the earth to serve as tempters. According to a plan of salvation as described by God the Father, Jesus would create the earth, under the direction of God the Father, as a place where humanity would be tested. After the resurrection all men and women except spirits that followed Lucifer and the sons of perdition would be assigned one of three degrees of glory. Within the highest degree, the Celestial Kingdom, there are three divisions, and those in the highest of these divisions would become gods and goddesses through a process called exaltation or "eternal progression". This would involve having spirit children and populating new worlds.

The Earth's creation, according to Mormon scripture, was not ex nihilo, but organized from existing matter. The faith teaches that this earth is just one of many inhabited worlds, and that there are many governing heavenly bodies, including a planet or star Kolob which is said to be nearest the throne of God. According to some Mormon sources, God the Father himself was once like a human, and lived on a planet with his own higher god.

Hinduism[link]

The Hindu cosmology and timeline is the closest to modern scientific timelines and even more which might indicate that the Big Bang is not the beginning of everything but just the start of the present cycle preceded by an infinite number of universes and to be followed by another infinite number of universes. It also includes an infinite number of universes at one given time.

The Rig Veda questions the origin of the cosmos in: "Neither being (sat) nor non-being was as yet. What was concealed? And where? And in whose protection?…Who really knows? Who can declare it? Whence was it born, and whence came this creation? The devas (demigods) were born later than this world's creation, so who knows from where it came into existence? None can know from where creation has arisen, and whether he has or has not produced it. He who surveys it in the highest heavens, he alone knows-or perhaps does not know." (Rig Veda 10. 129)

Large scale structure of the Universe according to one Hindu cosmology.

Map 2: Intermediate neighbourhood of the Earth according to one Hindu cosmology.

Map 3: Local neighbourhood of the Earth according to one Hindu cosmology.

The Rig Veda's view of the cosmos also sees one true divine principle self-projecting as the divine word, Vaak, 'birthing' the cosmos that we know, from the monistic Hiranyagarbha or Golden Womb. The Hiranyagarbha is alternatively viewed as Brahma, the creator who was in turn created by God, or as God (Brahman) himself. The universe is considered to constantly expand since creation and disappear into a thin haze after billions of years.^{[citation needed]} An alternate view is that the universe begins to contract after reaching its maximum expansion limits until it disappears into a fraction of a millimeter.^{[citation needed]} The creation begins anew after billions of years (Solar years) of non-existence.

The puranic view asserts that the universe is created, destroyed, and re-created in an eternally repetitive series of cycles. In Hindu cosmology, a universe endures for about 4,320,000,000 years (one day of Brahma, the creator or kalpa) and is then destroyed by fire or water elements. At this point, Brahma rests for one night, just as long as the day. This process, named pralaya (Cataclysm), repeats for 100 Brahma years (311 Trillion, 40 Billion Human Years) that represents Brahma's lifespan. Similarly at a given time there are an infinite number of Brahma's performing the creation of each of these universes that are infinite in number. It must be noted that Brahma is the creator but not necessarily regarded as God in Hinduism. He is mostly regarded as a creation of God / Brahman.

We are currently^[when?] believed to be in the 51st year of the present Brahma and so about 156 trillion years have elapsed since He was born as Brahma. After Brahma's "death", it is necessary that another 100 Brahma years (311 Trillion, 40 Billion Years) pass until a new Brahma is born and the whole creation begins anew. This process is repeated again and again, forever.

Brahma's day is divided in one thousand cycles (Maha Yuga, or the Great Year). Maha Yuga, during which life, including the human race appears and then disappears, has 71 divisions, each made of 14 Manvantara (1000) years. Each Maha Yuga lasts for 4,320,000 years. Manvantara is Manu's cycle, the one who gives birth and governs the human race.

Each Maha Yuga consists of a series of four shorter yugas, or ages. The yugas get progressively worse from a moral point of view as one proceeds from one yuga to another. As a result, each yuga is of shorter duration than the age that preceded it. The current Kali Yuga (Iron Age) began at midnight 17 February / 18 February in 3102 BC in the proleptic Julian calendar.

Space and time are considered to be maya (illusion). What looks like 100 years in the cosmos of Brahma could be thousands of years in other worlds, millions of years in some other worlds and 311 trillion and 40 billion years for our solar system and earth.

Islam[link]

Islam preaches that God, or Allah, created the universe, including Earth's physical environment and human beings. The highest goal is to visualize the cosmos as a book of symbols for meditation and contemplation for spiritual upliftment or as a prison from which the human soul must escape to attain true freedom in the spiritual journey to God. Islam elaborates on cosmology in many instances. A modern English translation of the Quran describes the creation of the universe as follows:"We have built the heaven with might, and We are Steadily Expanding it."51:47 ^[3] Earlier English translations like for example Ahmed Ali, The Noble Qur'an, Pickthal, Shakir and Yusuf Ali never specify the expansion as a process that is still going on so it seems to be an addition after the expansion of the universe became a generally accepted scientific fact.

Below here there are some other citations from the Quran on cosmology.

"Do not the Unbelievers see that the heavens and the earth were joined together (as one unit of creation), before we clove them asunder? We made from water every living thing. Will they not then believe?" 21:30 Yusuf Ali translation

"The Day that We roll up the heavens like a scroll rolled up for books (completed),- even as We produced the first creation, so shall We produce a new one: a promise We have undertaken: truly shall We fulfil it." 21:104 Yusuf Ali translation

Jainism[link]

Jain cosmology considers the loka, or universe, as an uncreated entity, existing since infinity, having no beginning or an end.^[4] Jain texts describe the shape of the universe as similar to a man standing with legs apart and arm resting on his waist. This Universe, according to Jainism, is narrow at the top, broad at the middle and once again becomes broad at the bottom.^[5]

Mahāpurāṇa of Ācārya Jinasena is famous for this quote: "Some foolish men declare that a creator made the world. The doctrine that the world was created is ill advised and should be rejected. If God created the world, where was he before the creation? If you say he was transcendent then and needed no support, where is he now? How could God have made this world without any raw material? If you say that he made this first, and then the world, you are faced with an endless regression."

Taoism[link]

The cosmology of Taoist philosophy is a complex mixture of different beliefs. There is a "primordial universe" Wuji (philosophy), and Hongjun Laozu, water or qi.^[6][7] It transformed into Taiji and multiplied into everything.^[8][9] The Pangu legend tells a formless chaos coalesced into a cosmic egg. Pangu emerged (or woke up) and separated Yin from Yang with a swing of his giant axe, creating the Earth (murky Yin) and the Sky (clear Yang). To keep them separated, Pangu stood between them and pushed up the Sky. After Pangu died, he became everything.

Yoonir, symbol of the Universe in Serer religion.^[10][11]

Serer religion[link]

Serer religion posits that, Rog, the creator deity, is the point of departure and conclusion.^[11] As farming people, trees play an important role in Serer religious cosmology and creation mythology. The Serer high priests and priestesses (the Saltigues) chart the Star of Sirius known as Yoonir in the Serer language and some of the Cangin languages. This star enables them to give accurate information as to when Serer farmers should start planting seeds among other things relevant to Serer lives and Serer country. The Star of Yoonir is the symbol of the universe in Serer cosmology.^[10][11]

See also[link]

• Bahá'í cosmology
• Raelian cosmology
• Zoroastrian cosmology

References[link]

This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (September 2010)

Carl Sagan
Sagan in 1980
Born	(1934-11-09)November 9, 1934 Brooklyn, New York, U.S.
Died	December 20, 1996(1996-12-20) (aged 62) Seattle, Washington, U.S.
Residence	United States[1]
Nationality	United States
Fields	Astronomy, astrophysics, cosmology, astrobiology, space science, planetary science
Institutions	Cornell University Harvard University Smithsonian Astrophysical Observatory University of California, Berkeley
Alma mater	University of Chicago (B.A.), (B.Sc.), (M.Sc.), (PhD)
Known for	Search for Extra-Terrestrial Intelligence (SETI) Cosmos: A Personal Voyage Cosmos Voyager Golden Record Pioneer plaque Contact Pale Blue Dot
Notable awards	NASA Distinguished Public Service Medal (1977) Pulitzer Prize for General Non-Fiction (1978) Oersted Medal (1990) National Academy of Sciences Public Welfare Medal (1994)

Carl Edward Sagan ( /ˈseɪɡɪn/; November 9, 1934 – December 20, 1996) was an American astronomer, astrophysicist, cosmologist, author, science popularizer, and science communicator in astronomy and natural sciences. He published more than 600 scientific papers^[2] and articles and was author, co-author or editor of more than 20 books. He advocated scientifically skeptical inquiry and the scientific method, pioneered exobiology and promoted the Search for Extra-Terrestrial Intelligence (SETI).

Sagan is known for his popular science books and for the award-winning 1980 television series Cosmos: A Personal Voyage, which he narrated and co-wrote.^[3] The book Cosmos was published to accompany the series. Sagan wrote the novel Contact, the basis for a 1997 film of the same name.

Early life[link]

Carl Sagan was born in Brooklyn, New York,^[4] to a Ukrainian Jewish family. His father, Sam Sagan, was an immigrant garment worker from Kamenets-Podolsk, Ukraine;^[5] his mother, Rachel Molly Gruber, a housewife. Carl was named in honor of Rachel's biological mother, Chaiya Clara, in Sagan's words, "the mother she never knew." Sagan graduated from Rahway High School in Rahway, New Jersey, in 1951.^[6]

He had a sister, Carol, and the family lived in a modest apartment near the Atlantic Ocean, in Bensonhurst, a Brooklyn neighborhood. According to Sagan, they were Reform Jews, the most liberal of the three main Jewish groups. Both Sagan and his sister agree 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 meat."^[6]:12 During the height of the Depression, his father had to accept a job as a theater usher.

According to biographer Keay Davidson, Sagan's "inner war" was a result of his close relations with both his parents, who were in many ways "opposites." Sagan traced his later analytical urges to his mother, a woman who had known "extreme poverty as a child," and had grown up almost homeless in New York City during World War I and the 1920s.^[6]:2 She had her own intellectual ambitions as a young woman, but they were blocked by social restrictions, because of her poverty, her being a woman and wife, and her Jewish ethnicity. Davidson notes that she therefore "worshiped her only son, Carl. He would fulfill her unfulfilled dreams."^[6]:2

However, his "sense of wonder" came from his father, who was a "quiet and soft-hearted escapee from the Czar." In his free time, he gave apples to the poor, or helped soothe labor-management tensions within New York's "tumultuous" garment industry.^[6]:2 Although he was "awed" by Carl's "brilliance, his boyish chatter about stars and dinosaurs," he took his son's inquisitiveness in stride, as part of his growing up.^[6]:2 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.^[6]:9 Sagan describes his parents' influence on his later thinking:

My parents were not scientists. They knew almost nothing about science. But in introducing me simultaneously to skepticism and to wonder, they taught me the two uneasily cohabiting modes of thought that are central to the scientific method.^[7]

1939 World's Fair[link]

Sagan recalls that one of his best experiences was when he was four or five years old, his parents took him to the 1939 New York World's Fair. 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!"^[6]:14 At other exhibits, he remembered how a flashlight that shined on a photoelectric cell created a cracking sound, and how the sound from a tuning fork became a wave on an oscilloscope. He also witnessed the future media technology that would replace radio: television. Sagan wrote:

Plainly, the world held wonders of a kind I had never guessed. How could a tone become a picture and light become a noise?^[6]:14

He also saw one of the Fair's most publicized events, the burial of a time capsule at Flushing Meadows, 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 created similar time capsules, but ones that would be sent out into the galaxy. These were the Pioneer plaque and the Voyager Golden Record records, all of which were spinoffs of Sagan's memories of the World Fair.^[6]:15

World War II[link]

During World War II, Sagan's family worried about the fate of their European relatives. Sagan, however, was generally unaware of the details of the ongoing war. He writes, "Sure, we had relatives who were caught up in the Holocaust. Hitler 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."^[6]:15 Sagan's book, The Demon-Haunted World (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.^[7]

Inquisitiveness about nature[link]

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:

I went to the librarian and asked for a book about stars ... And the answer was stunning. It was that the Sun was a star but really close. The stars were suns, but so far away they were just little points of light ... The scale of the universe suddenly opened up to me. It was a kind of religious experience. There was a magnificence to it, a grandeur, a scale which has never left me. Never ever left me.^[6]:18

About the time he was six or seven, he and a close friend took trips to the American Museum of Natural History in New York City. While there, they went to the Hayden Planetarium and walked around the museum's exhibits of space objects, such as meteorites, and displays of dinosaurs and animals in natural settings. Sagan writes about those visits:

I was transfixed by the dioramas—lifelike representations of animals and their habitats all over the world. Penguins on the dimly lit Antarctic ice; ... a family of gorillas, the male beating his chest, ... an American grizzly bear standing on his hind legs, ten or twelve feet tall, and staring me right in the eye.^[6]:18

His parents helped nurture his growing interest in science by buying him chemistry sets and reading materials.^[8] His interest in space, however, was his primary focus, especially after reading science fiction stories by writers such as Edgar Rice Burroughs, which stirred his imagination about life on other planets, such as Mars. 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."^[7]

Education and scientific career[link]

He attended the University of Chicago, where he participated in the Ryerson Astronomical Society,^[9] received a bachelor of arts in self-proclaimed "nothing" with general and special honors in 1954, a bachelor of science in physics in 1955, and a master of science in physics in 1956 before earning a PhD in astronomy and astrophysics in 1960.^[10][11][12] During his time as an honors program undergraduate, Sagan worked in the laboratory of the geneticist H. J. Muller and wrote a thesis on the origins of life with physical chemist H.C. Urey. From 1960 to 1962 Sagan was a Miller Fellow at the University of California, Berkeley. From 1962 to 1968, he worked at the Smithsonian Astrophysical Observatory in Cambridge, Massachusetts.

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

Sagan was associated with the US 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 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. He conceived the idea of adding an unalterable and universal message on spacecraft destined to leave the solar system that could potentially be understood by any extraterrestrial intelligence that might find it. Sagan assembled the first physical message that was sent into space: a gold- anodized plaque, attached to the space probe Pioneer 10, launched in 1972. Pioneer 11, also carrying another copy of the plaque, was launched the following year. He continued to refine his designs; the most elaborate message he helped to develop and assemble was the Voyager Golden Record that was sent out with the Voyager space probes in 1977. Sagan often challenged the decisions to fund the Space Shuttle and Space Station at the expense of further robotic missions.^[13]

Sagan taught a course on critical thinking at Cornell University until he died in 1996 from pneumonia, a few months after finding that he was in remission of myelodysplastic syndrome.

Scientific achievements[link]

Sagan's contributions were central to the discovery of the high surface temperatures of the planet Venus. In the early 1960s no one knew for certain the basic conditions of that planet's surface, and Sagan listed the possibilities in a report later depicted for popularization in a Time-Life book, Planets. His own view was that Venus was dry and very hot as opposed to the balmy paradise others had imagined. He had investigated radio emissions from Venus and concluded that there was a surface temperature of 500 °C (900 °F). As a visiting scientist to NASA's Jet Propulsion Laboratory, he contributed to the first Mariner missions to Venus, working on the design and management of the project. Mariner 2 confirmed his conclusions on the surface conditions of Venus in 1962.

Sagan was among the first to hypothesize that Saturn's moon Titan might possess oceans of liquid compounds on its surface and that Jupiter's moon Europa might possess subsurface oceans of water. This would make Europa potentially habitable.^[14] Europa's subsurface ocean of water was later indirectly confirmed by the 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 molecules constantly raining down onto Titan's surface.^[15]

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

Sagan is best known, however, for his research on the possibilities of extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by radiation.^[16]

He is also the 1994 recipient of the Public Welfare Medal, the highest award of the National Academy of Sciences for "distinguished contributions in the application of science to the public welfare."^[17] He was denied membership in the Academy, reportedly because his media activities made him unpopular with many other scientists.^[18]

Scientific advocacy[link]

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

Sagan's ability to convey his ideas allowed many people to better understand the cosmos—simultaneously emphasizing the value and worthiness of the human race, and the relative insignificance of the Earth in comparison to the universe. He delivered the 1977 series of Royal Institution Christmas Lectures in London.^[19] He hosted and, with Ann Druyan, co-wrote and co-produced the highly popular thirteen-part PBS television series Cosmos: A Personal Voyage modeled on Jacob Bronowski's The Ascent of Man.

Cosmos covered a wide range of scientific subjects including the origin of life and a perspective of our place in the universe. The series was first broadcast by the Public Broadcasting Service in 1980, winning an Emmy and a Peabody Award. It has been broadcast in more than 60 countries and seen by over 500 million people,^[3][20] making it the most widely watched PBS program in history.^[21] In addition, 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 new public television series Cosmos, [and] takes the controls of his fantasy spaceship."^[22]

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-forms. Sagan was so persuasive that by 1982 he was able to get a petition advocating SETI published in the journal Science and signed by 70 scientists including seven Nobel Prize winners. This was a tremendous increase in the respectability of this controversial field. Sagan also helped Dr. Frank Drake write the Arecibo message, a radio message beamed into space from the Arecibo radio telescope on November 16, 1974, aimed at informing potential extraterrestrials about Earth.

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

At the height of the Cold War, Sagan became involved in public awareness efforts for the effects of nuclear war when a mathematical climate model suggested that a substantial nuclear exchange could upset the delicate balance of life on Earth. He was one of five authors—the "S" of the "TTAPS" report as the research paper came to be known. He eventually co-authored the scientific paper hypothesizing a global nuclear winter following nuclear war.^[23] He also co-authored the book A Path Where No Man Thought: Nuclear Winter and the End of the Arms Race, a comprehensive examination of the phenomenon of nuclear winter.

Sagan also wrote books to popularize science which reflected and expanded upon some of the themes of A Personal Voyage, and became the best-selling science book ever published in English;^[24] The Dragons of Eden: Speculations on the Evolution of Human Intelligence, which won a Pulitzer Prize; and Broca's Brain: Reflections on the Romance of Science. Sagan also wrote the best-selling science fiction novel Contact in 1985, based on a film treatment he wrote with his wife in 1979, but he did not live to see the book's 1997 motion picture adaptation, which starred Jodie Foster and won the 1998 Hugo Award for Best Dramatic Adaption.

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

He wrote a sequel to Cosmos, Pale Blue Dot: A Vision of the Human Future in Space, which was selected as a notable book of 1995 by The New York Times. He appeared on PBS' Charlie Rose program in January 1995.^[25] Sagan also wrote an introduction for the bestselling book by Stephen Hawking, A Brief History of Time. Sagan was also known for his popularization of science, his efforts to increase scientific understanding among the general public, and his positions in favor of scientific skepticism and against pseudoscience, such as his debunking of the Betty and Barney Hill abduction. To mark the tenth anniversary of Sagan's death, 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.^[26]

Sagan hypothesized in January 1991 that enough smoke from the 1991 Kuwaiti oil fires "might get so high as to disrupt agriculture in much of South Asia ..." He later conceded in The Demon-Haunted World that this prediction did not turn out to be correct: "it was pitch black at noon and temperatures dropped 4°–6 °C over the Persian Gulf, but not much smoke reached stratospheric altitudes and Asia was spared."^[27] A 2007 study noted that modern computer models have been applied to the Kuwait oil fires, finding that individual smoke plumes are not able to loft smoke into the stratosphere, but that smoke from fires covering a large area, like some forest fires or the burning of cities that would be expected to follow a nuclear strike, would loft significant amounts of smoke into the stratosphere.^{[28][29][30][31]}

In his later years Sagan advocated the creation of an organized search for near Earth objects that might impact the Earth.^[32] When others suggested creating large nuclear bombs that could be used to alter the orbit of a NEO that was predicted to hit the Earth, Sagan proposed the Deflection Dilemma: If we create the ability to deflect an asteroid away from the Earth, then we also create the ability to deflect an asteroid towards the Earth—providing an evil power with a true doomsday bomb.^[33][34]

Billions and billions[link]

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

From Cosmos and his frequent appearances on The Tonight Show Starring Johnny Carson, Sagan became associated with the catchphrase "billions and billions". Sagan stated that he never actually used the phrase in the Cosmos series.^[35] The closest that he ever came was in the book Cosmos, where he talked of "billions upon billions":^[36]

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

—Carl Sagan, Cosmos, chapter 1, page 3^[37]

However, his frequent use of the word billions, and distinctive delivery emphasizing the "b" (which he did intentionally, in place of more cumbersome alternatives such as "billions with a 'b'", in order to distinguish the word from "millions" in viewers' minds),^[35] made him a favorite target of comic performers, including Johnny Carson,^[38] 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.^[35]

Similarly he is also known for expressing wonderment at the vastness of space and time, as in his phrase "The total number of stars in the Universe is larger than all the grains of sand on all the beaches of the planet Earth."

Sagan units[link]

As a humorous tribute to him, a sagan has been defined as a unit of measurement equal to at least four billion, since the smallest number that may be described as billions and billions must be two billion plus two billion.^[39][40]

Social concerns[link]

Sagan believed that the Drake equation, on substitution of reasonable estimates, suggested that a large number of extraterrestrial civilizations would form, but that the lack of evidence of such civilizations highlighted by the Fermi paradox suggests technological civilizations tend to self-destruct. This stimulated his interest in identifying and publicizing ways that humanity could destroy itself, with the hope of avoiding such a cataclysm and eventually becoming a spacefaring species. Sagan's deep concern regarding the potential destruction of human civilization in a nuclear holocaust was conveyed in a memorable cinematic sequence in the final episode of Cosmos, called "Who Speaks for Earth?" Sagan had already resigned from the Air Force Scientific Advisory Board and voluntarily surrendered his top secret clearance in protest over the Vietnam War.^[41] Following his marriage to his third wife (novelist Ann Druyan) in June 1981, Sagan became more politically active—particularly in opposing escalation of the nuclear arms race under President Ronald Reagan.

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

When Soviet leader Mikhail Gorbachev declared a unilateral moratorium on the testing of nuclear weapons, which would begin on August 6, 1985—the 40th anniversary of the atomic bombing of Hiroshima—the Reagan administration dismissed the dramatic move as nothing more than propaganda, and refused to follow suit. In response, US anti-nuclear and peace activists staged a series of protest actions at the Nevada Test Site, beginning on Easter Sunday in 1986 and continuing through 1987. Hundreds of people were arrested, including Sagan, who was arrested on two separate occasions as he climbed over a chain-link fence at the test site.^[42]

Personal life and beliefs[link]

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

Isaac Asimov described Sagan as one of only two people he ever met whose intellect surpassed his own. The other, he claimed, was the computer scientist and artificial intelligence expert Marvin Minsky.^[43]

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

"Some people think God is an outsized, light-skinned male with a long white beard, sitting on a throne somewhere up there in the sky, busily tallying the fall of every sparrow. Others—for example Baruch Spinoza and Albert Einstein—considered God to be essentially the sum total of the physical laws which describe the universe. I do not know of any compelling evidence for anthropomorphic patriarchs controlling human destiny from some hidden celestial vantage point, but it would be madness to deny the existence of physical laws."^[44]

In another description of his view of God, Sagan emphatically writes:

"The idea that God is an oversized white male with a flowing beard who sits in the sky and tallies the fall of every sparrow is ludicrous. But if by God one means the set of physical laws that govern the universe, then clearly there is such a God. This God is emotionally unsatisfying... it does not make much sense to pray to the law of gravity."^[45]

On atheism, Sagan commented in 1981:

"An atheist is someone who is certain that God does not exist, someone who has compelling evidence against the existence of God. I know of no such compelling evidence. Because God can be relegated to remote times and places and to ultimate causes, we would have to know a great deal more about the universe than we do now to be sure that no such God exists. To be certain of the existence of God and to be certain of the nonexistence of God seem to me to be the confident extremes in a subject so riddled with doubt and uncertainty as to inspire very little confidence indeed".^[46]

In reply to a question in 1996 about his religious beliefs, Sagan answered, "I'm agnostic."^[47] Sagan's views on religion have been interpreted as a form of pantheism comparable to Einstein's belief in Spinoza's God.^[48] Sagan maintained that the idea of a creator of the universe was difficult to prove or disprove and that the only conceivable scientific discovery that could challenge it would be an infinitely old universe.^[49] According to his last wife, Ann Druyan, he was not a believer:

When my husband died, because he was so famous and known for not being a believer, many people would come up to me—it still sometimes happens—and ask me if Carl changed at the end and converted to a belief in an afterlife. They also frequently ask me if I think I will see him again. Carl faced his death with unflagging courage and never sought refuge in illusions. The tragedy was that we knew we would never see each other again. I don't ever expect to be reunited with Carl.^[50]

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

Carl Sagan (center) speaks with CDC employees in 1988.

Sagan is also widely regarded as a freethinker or skeptic; one of his most famous quotations, in Cosmos, was, "Extraordinary claims require extraordinary evidence"^[51] (called the "Sagan Standard" by some^[52]). This was based on a nearly identical statement by fellow founder of the Committee for the Scientific Investigation of Claims of the Paranormal, Marcello Truzzi, "An extraordinary claim requires extraordinary proof."^[53][54] This idea originated with Pierre-Simon Laplace (1749–1827), a French mathematician and astronomer who said, "The weight of evidence for an extraordinary claim must be proportioned to its strangeness."^[55]

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

Sagan warned against humans' tendency 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."^[56]

Sagan was a user and advocate of marijuana. Under the pseudonym "Mr. X", he contributed an essay about smoking cannabis to the 1971 book Marihuana Reconsidered.^[57][58] 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.^[59][60][61] Not long after his death, widow Ann Druyan had gone on to preside over the board of directors of NORML, a foundation dedicated to reforming cannabis laws.^[62]

In 1994, engineers at 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.^[4] 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 "Butt-Head Astronomer".^[63][64] Sagan then sued Apple for libel, a form of defamation, in federal court. The court granted Apple's motion to dismiss Sagan's claims and opined in 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'."^[63][65] Sagan then sued for Apple's original use of his name and likeness, but again lost.^[66] Sagan appealed the ruling.^[66] 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."^[67]

Sagan briefly served as an adviser on Stanley Kubrick's film 2001: A Space Odyssey.^[6] Sagan proposed that the film would suggest, rather than depict, extraterrestrial superintelligence.^[68]

Sagan and UFOs[link]

Sagan had some interest in UFO reports from at least August 3, 1952 when he wrote a letter to U.S. Secretary of State Dean Acheson to ask how the U.S. would respond if flying saucers turned out to be extraterrestrial.^[69] He later had several conversations on the subject in 1964 with Jacques Vallee.^[70] Though quite skeptical of any extraordinary answer to the UFO question, Sagan thought scientists should study the phenomenon, at least because there was widespread public interest in UFO reports.

Stuart Appelle notes that Sagan "wrote frequently on what he perceived as the logical and empirical fallacies regarding UFOs and the abduction experience. Sagan rejected an extraterrestrial explanation for the phenomenon but felt there were both empirical and pedagogical benefits for examining UFO reports and that the subject was, therefore, a legitimate topic of study."^[71]

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

Ron Westrum writes that "The high point of Sagan's treatment of the UFO question was the AAAS's symposium in 1969. A wide range of educated opinions on the subject were offered by participants, including not only proponents such as James McDonald and J. Allen Hynek but also skeptics like astronomers William Hartmann and Donald Menzel. The roster of speakers was balanced, and it is to Sagan's credit that this event was presented in spite of pressure from Edward Condon".^[70] With physicist Thornton Page, Sagan edited the lectures and discussions given at the symposium; these were published in 1972 as UFOs: A Scientific Debate. Some of Sagan's many books examine UFOs (as did one episode of Cosmos) and he claimed a religious undercurrent to the phenomenon.

Sagan again revealed his views on interstellar travel in his 1980 Cosmos series. In one of his last written works, Sagan argued that the chances of extraterrestrial spacecraft visiting Earth are vanishingly small. However, Sagan did think it plausible that Cold War concerns contributed to governments misleading their citizens about UFOs, and that "some UFO reports and analyses, and perhaps voluminous files, have been made inaccessible to the public which pays the bills ... It's time for the files to be declassified and made generally available." He cautioned against jumping to conclusions about suppressed UFO data and stressed that there was no strong evidence that aliens were visiting the Earth either in the past or present.^[72]

Death[link]

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

After a long and difficult fight with myelodysplasia, which included three bone marrow transplants, Sagan died of pneumonia at the age of 62 at the Fred Hutchinson Cancer Research Center in Seattle, Washington, on December 20, 1996.^[73] He was buried at Lakeview Cemetery in Ithaca, New York.^[74]

Posthumous recognition[link]

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

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.^[75]

The landing site of the unmanned Mars Pathfinder spacecraft was renamed the Carl Sagan Memorial Station on July 5, 1997. Asteroid 2709 Sagan is named in his honor.

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

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

Sagan has at least three awards named in his honor:

• The Carl Sagan Memorial Award presented jointly since 1997 by the American Astronomical Society (AAS) 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.^[76]

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

On December 20, 2006, the tenth anniversary of Sagan's death, a blogger, Joel Schlosberg, organized a Carl Sagan "blog-a-thon" to commemorate Sagan's death, and the idea was supported by Nick Sagan.^[77] Many members of the blogging community participated.

August 2007 the Independent Investigative Group IIG awarded Sagan posthumously a Lifetime Achievement Award. This honor has also been awarded to Harry Houdini and James Randi.^[78]

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 twenty-million views worldwide on the popular user generated website Youtube, and have exposed a new generation to the interconnected grandeur of the universe as Sagan described them in his documentary series.^[79]

Awards and honors[link]

NASA Distinguished Public Service Medal

• Annual Award for Television Excellence—1981—Ohio State University—PBS series Cosmos
• Apollo Achievement Award—National Aeronautics and Space Administration
• NASA Distinguished Public Service Medal—National Aeronautics and Space Administration (twice)
• Emmy—Outstanding Individual Achievement—1981—PBS series Cosmos
• Emmy—Outstanding Informational Series—1981—PBS series Cosmos
• Exceptional Scientific Achievement Medal—National Aeronautics and Space Administration
• Helen Caldicott Leadership Award – Awarded by Women's Action for Nuclear Disarmament
• Hugo Award—1981—Cosmos
• Humanist of the Year—1981—Awarded by the American Humanist Association
• In Praise of Reason Award—1987—Committee for the Scientific Investigation of Claims of the Paranormal
• Isaac Asimov Award—1994—Committee for the Scientific Investigation of Claims of the Paranormal
• John F. Kennedy Astronautics Award—American Astronautical Society
• John W. 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
• Konstantin Tsiolkovsky Medal—Awarded by the Soviet Cosmonauts Federation
• Locus Award 1986—Contact
• Lowell Thomas Award—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—1980—PBS series Cosmos
• Prix Galbert—The international prize of Astronautics
• Public Welfare Medal—1994—National Academy of Sciences^[80]
• Pulitzer Prize for General Non-Fiction—1978—The Dragons of Eden
• SF Chronicle Award—1998—Contact
• Named the "99th Greatest American" on the June 5, 2005, Greatest American show on the Discovery Channel
• Named an honorary member of the Demosthenian Literary Society on November 10, 2011
• 2009 New Jersey Hall of Fame inductee.^[81]

Publications[link]

• Planets (LIFE Science Library), Sagan, Carl, Jonathan Norton Leonard and editors of Life, Time, Inc., 1966
• Intelligent Life in the Universe, I.S. Shklovskii coauthor, Random House, 1966, ISBN 1-892803-02-X, 509 pgs (note: republished in 1998 by Emerson-Adams Press)
• UFOs: A Scientific Debate, Thornton Page coauthor, Cornell University Press, 1972, 310 pgs
• Communication with Extraterrestrial Intelligence. MIT Press, 1973, 428 pgs
• Mars and the Mind of Man, Sagan, Carl, et al., Harper & Row, 1973, 143 pgs
• The Cosmic Connection: An Extraterrestrial Perspective, Jerome Agel coauthor, Anchor Press, 1973, ISBN 0-521-78303-8, 301 pgs
• Other Worlds. Bantam Books, 1975
• Murmurs of Earth: The Voyager Interstellar Record, Sagan, Carl, et al., Random House, ISBN 0-394-41047-5, 1978
• The Dragons of Eden: Speculations on the Evolution of Human Intelligence. Ballantine Books, 1978, ISBN 0-345-34629-7, 288 pgs
• Broca's Brain: Reflections on the Romance of Science. Ballantine Books, 1979, ISBN 0-345-33689-5, 416 pgs
• Cosmos. Random House, 1980. Random House New Edition, May 7, 2002, ISBN 0-375-50832-5, 384 pgs
• The Cold and the Dark: The World after Nuclear War, Sagan, Carl et al., Sidgwick & Jackson, 1985
• Comet, Ann Druyan coauthor, Ballantine Books, 1985, ISBN 0-345-41222-2, 496 pgs
• Contact. Simon and Schuster, 1985; Reissued August 1997 by Doubleday Books, ISBN 1-56865-424-3, 352 pgs
• A Path Where No Man Thought: Nuclear Winter and the End of the Arms Race, Richard Turco coauthor, Random House, 1990, ISBN 0-394-58307-8, 499 pgs
• Shadows of Forgotten Ancestors: A Search for Who We Are, Ann Druyan coauthor, Ballantine Books, October 1993, ISBN 0-345-38472-5, 528 pgs
• Pale Blue Dot: A Vision of the Human Future in Space. Random House, November 1994, ISBN 0-679-43841-6, 429 pgs
• The Demon-Haunted World: Science as a Candle in the Dark. Ballantine Books, March 1996, ISBN 0-345-40946-9, 480 pgs (note: the book was first published and copyrighted in 1995 with an errata slip inserted)
• Billions and Billions: Thoughts on Life and Death at the Brink of the Millennium, Ann Druyan coauthor, Ballantine Books, June 1997, ISBN 0-345-37918-7, 320 pgs
• The Varieties of Scientific Experience: A Personal View of the Search for God, Carl Sagan (writer) & Ann Druyan (editor), 1985 Gifford lectures, Penguin Press HC, November 2006, ISBN 1-59420-107-2, 304 pgs

References[link]

Further reading[link]

• Davidson, Keay (1999). Carl Sagan: A Life. New York: John Wiley & Sons. pp. 33–41. ISBN 0-471-25286-7. 
• Head, Tom (ed.) (2005). Conversations with Carl Sagan. Jackson, Mississippi: University Press of Mississippi. ISBN 1-57806-736-7. 
• Poundstone, William (1999). Carl Sagan: A Life in the Cosmos. New York: Henry Holt & Company. ISBN 0-8050-5766-8. 
• Morrison, David (2006). "Carl Sagan: The People's Astronomer" (PDF). AmeriQuests 3 (2). http://ejournals.library.vanderbilt.edu/ameriquests/include/getdoc.php?id=402&article=93&mode=pdf. 
• Achenbach, Joel (1999). Captured by Aliens: the search for life and truth in a very large universe. New York: Simon & Schuster. ISBN 0-684-84856-2. [Includes detailed account of Sagan's role in the search for extraterrestrial life. Lay summary]. 

External links[link]

Find more about Carl Sagan on Wikipedia's sister projects:
	Images and media from Commons
	Quotations from Wikiquote
	Source texts from Wikisource

• The Carl Sagan Portal
• Video of skit from The Tonight Show Starring Johnny Carson mentioning "billions and billions"
• BBC Radio program "Great Lives" on Carl Sagan's life
• A Man whose time Has come—Interview with Carl Sagan by Ian Ridpath, New Scientist 1974 July 4
• Carl Sagan at the Internet Movie Database
• Works by or about Carl Sagan in libraries (WorldCat catalog)
• Carl Sagan Prize for Science Popularization
• Sagan Medal for Excellence in Public Communication in Planetary Science, presented by the American Astronomical Society's Division for Planetary Sciences (AAS/DPS)
• Carl Sagan Center for the Study of Life in the Universe, SETI Institute
• Carl Sagan's Life and Legacy as Scientist, Teacher, and Skeptic, Committee for Skeptical Inquiry
• A Tribute to Carl Sagan: Our Place in the Universe, The Skeptics Society

v t e Carl Sagan Books Mars and the Mind of Man The Dragons of Eden: Speculations on the Evolution of Human Intelligence Broca's Brain: Reflections on the Romance of Science Cosmos The Nuclear Winter: The World After Nuclear War Contact Comet A Path Where No Man Thought: Nuclear Winter and the End of the Arms Race Shadows of Forgotten Ancestors: A Search for Who We Are Pale Blue Dot: A Vision of the Human Future in Space The Demon-Haunted World: Science as a Candle in the Dark Billions and Billions: Thoughts on Life and Death at the Brink of the Millennium The Varieties of Scientific Experience: A Personal View of the Search for God Media Cosmos: A Personal Voyage Contact See also SETI Pioneer plaque Voyager Golden Record Pale Blue Dot Linda Salzman Sagan Nick Sagan Ann Druyan

Richard Dawkins
Dawkins in 2010 at Cooper Union in New York City
Born	Clinton Richard Dawkins (1941-03-26) 26 March 1941 (age 71) Nairobi, Kenya Colony
Nationality	British
Education	MA, DPhil (Oxon)
Alma mater	Balliol College, Oxford
Occupation	Ethologist
Years active	1967–present
Employer	University of California, Berkeley University of Oxford
Organization	Fellow of the Royal Society Fellow of the Royal Society of Literature
Known for	Gene-centered view of evolution, concept of the meme, as well as advocacy of atheism and science.
Notable work(s)	The Selfish Gene (1976) The Extended Phenotype (1982) The Blind Watchmaker (1986) The God Delusion (2006)
Influenced by	Charles Darwin, Ronald Fisher, George C. Williams, W. D. Hamilton, Daniel Dennett, Bertrand Russell, Nikolaas Tinbergen, John Maynard Smith, Robert Trivers
Spouse	Marian Stamp Dawkins (m. 1967–1984) Eve Barham (m. 1984–?) Lalla Ward (m. 1992–present)
Children	Juliet Emma Dawkins (born 1984)
Parents	Clinton John Dawkins Jean Mary Vyvyan (née Ladner)
Awards	ZSL Silver Medal (1989) Faraday Award (1990) Kistler Prize (2001)
Website
The Richard Dawkins Foundation

Clinton Richard Dawkins, FRS, FRSL (born 26 March 1941), known as Richard Dawkins, is a British ethologist, evolutionary biologist and author. He is an emeritus fellow of New College, Oxford,^[1] and was the University of Oxford's Professor for Public Understanding of Science from 1995 until 2008.^[2]

Dawkins came to prominence with his 1976 book The Selfish Gene, which popularised the gene-centered view of evolution and introduced the term meme. In 1982 he introduced an influential concept into evolutionary biology, presented in his book The Extended Phenotype, that the phenotypic effects of a gene are not necessarily limited to an organism's body, but can stretch far into the environment, including the bodies of other organisms.^[3]

Dawkins is an atheist, a vice president of the British Humanist Association, and a supporter of the Brights movement.^[4] He is well known for his criticism of creationism and intelligent design. In his 1986 book The Blind Watchmaker, he argued against the watchmaker analogy, an argument for the existence of a supernatural creator based upon the complexity of living organisms. Instead, he described evolutionary processes as analogous to a blind watchmaker. He has since written several popular science books, and makes regular television and radio appearances, predominantly discussing these topics. In his 2006 book The God Delusion, Dawkins contends that a supernatural creator almost certainly does not exist and that religious faith is a delusion—"a fixed false belief."^[5] As of January 2010 the English-language version has sold more than two million copies and had been translated into 31 languages.^[6]

Biography[link]

Dawkins was born in Nairobi, Kenya.^[7] His father, Clinton John Dawkins (1915–2010),^[8] was an agricultural civil servant in the British colonial service, in Nyasaland (now Malawi). Dawkins has a younger sister.^[9] His father was called up into the King's African Rifles during World War II,^[10][11] returning to England in 1949, when Dawkins was eight. His father had inherited a country estate, Over Norton Park, which he turned into a commercial farm.^[8] Both his parents were interested in natural sciences; they answered Dawkins' questions in scientific terms.^[12]

Dawkins describes his childhood as "a normal Anglican upbringing".^[13] He was confirmed, and embraced Christianity until his mid-teens, at which point he concluded that the theory of evolution was a better explanation for life's complexity, and ceased believing in a god.^[9] Dawkins states: "the main residual reason why I was religious was from being so impressed with the complexity of life and feeling that it had to have a designer, and I think it was when I realised that Darwinism was a far superior explanation that pulled the rug out from under the argument of design. And that left me with nothing."^[9]

He attended Oundle, a Church of England school,^[9] from 1954 to 1959. He studied zoology at Balliol College, Oxford, where he was tutored by Nobel Prize–winning ethologist Nikolaas Tinbergen, graduating in 1962. He continued as a research student under Tinbergen's supervision, receiving his M.A. and D.Phil. degrees by 1966, and remained a research assistant for another year.^[7] Tinbergen was a pioneer in the study of animal behaviour, particularly in the areas of instinct, learning and choice.^[14] Dawkins' research in this period concerned models of animal decision-making.^[15]

From 1967 to 1969, he was an assistant professor of zoology at the University of California, Berkeley. During this period, the students and faculty at UC Berkeley were largely opposed to the ongoing Vietnam War, and Dawkins became heavily involved in the anti-war demonstrations and activities.^[16] He returned to the University of Oxford in 1970 taking a position as a lecturer, and in 1990, as a reader in zoology. In 1995 he was appointed Simonyi Professor for the Public Understanding of Science at Oxford, a position that had been endowed by Charles Simonyi with the express intention that the holder "be expected to make important contributions to the public understanding of some scientific field",^[17] and that its first holder should be Richard Dawkins.^[18]

Since 1970 he has been a fellow of New College.^[19] He has delivered a number of inaugural and other lectures, including the Henry Sidgwick Memorial Lecture (1989), first Erasmus Darwin Memorial Lecture (1990), Michael Faraday Lecture (1991), T. H. Huxley Memorial Lecture (1992), Irvine Memorial Lecture (1997), Sheldon Doyle Lecture (1999), Tinbergen Lecture (2004) and Tanner Lectures (2003).^[7] In 1991 he gave the Royal Institution Christmas Lectures for Children. He has also served as editor of a number of journals, and has acted as editorial advisor to the Encarta Encyclopedia and the Encyclopedia of Evolution. He is a senior editor of the Council for Secular Humanism's Free Inquiry magazine, for which he also writes a column. He has been a member of the editorial board of Skeptic magazine since its foundation.^[20]

He has sat on judging panels for awards as diverse as the Royal Society's Faraday Award and the British Academy Television Awards,^[7] and has been president of the Biological Sciences section of the British Association for the Advancement of Science. In 2004 Balliol College, Oxford instituted the Dawkins Prize, awarded for "outstanding research into the ecology and behaviour of animals whose welfare and survival may be endangered by human activities".^[21] In September 2008, he retired from his professorship, announcing plans to "write a book aimed at youngsters in which he will warn them against believing in 'anti-scientific' fairytales."^[22]

Personal life[link]

On 19 August 1967, Dawkins married fellow ethologist Marian Stamp in Annestown, County Waterford, Ireland;^[23] they divorced in 1984. Later that same year, on 1 June, he married Eve Barham (19 August 1951^[24]–28 February 1999) in Oxford. They had a daughter, Juliet Emma Dawkins (born 1984, Oxford).^[24] Dawkins and Barham also divorced^[25] and she later died of cancer.^[26][27] In 1992 he married actress Lalla Ward^[25] in Kensington and Chelsea, London.^[24] Dawkins met her through their mutual friend Douglas Adams,^[28] who had worked with her on the BBC's Doctor Who.

Work[link]

Evolutionary biology[link]

Dawkins at the University of Texas at Austin, March 2008

In his scientific works, Dawkins is best known for his popularisation of the gene-centred view of evolution. This view is most clearly set out in his books The Selfish Gene (1976), where he notes that "all life evolves by the differential survival of replicating entities", and The Extended Phenotype (1982), in which he describes natural selection as "the process whereby replicators out-propagate each other".^[29] In his role as an ethologist, interested in animal behaviour and its relation to natural selection, he advocates the idea that the gene is the principal unit of selection in evolution.

Dawkins has consistently been sceptical about non-adaptive processes in evolution (such as spandrels, described by Gould and Lewontin)^[30] and about selection at levels "above" that of the gene.^[31] He is particularly sceptical about the practical possibility or importance of group selection as a basis for understanding altruism.^[32] This behaviour appears at first to be an evolutionary paradox, since helping others costs precious resources and decreases one's own fitness. Previously, many had interpreted this as an aspect of group selection: individuals were doing what was best for the survival of the population or species as a whole, and not specifically for themselves. British evolutionary biologist W. D. Hamilton had used the gene-centred view to explain altruism in terms of inclusive fitness and kin selection − that individuals behave altruistically toward their close relatives, who share many of their own genes.^[33][a] Similarly, Robert Trivers, thinking in terms of the gene-centred model, developed the theory of reciprocal altruism, whereby one organism provides a benefit to another in the expectation of future reciprocation.^[34] Dawkins popularised these ideas in The Selfish Gene, and developed them in his own work.^[35]

He has also been strongly critical of the Gaia philosophy theory of the independent scientist James Lovelock.^[36][37][38]

Critics of Dawkins' approach suggest that taking the gene as the unit of selection − of a single event in which an individual either succeeds or fails to reproduce − is misleading, but that the gene could be better described as a unit of evolution − of the long-term changes in allele frequencies in a population.^[39] In The Selfish Gene, Dawkins explains that he is using George C. Williams' definition of the gene as "that which segregates and recombines with appreciable frequency."^[40] Another common objection is that genes cannot survive alone, but must cooperate to build an individual, and therefore cannot be an independent "unit".^[41] In The Extended Phenotype, Dawkins suggests that because of genetic recombination and sexual reproduction, from an individual gene's viewpoint all other genes are part of the environment to which it is adapted.

Advocates for higher levels of selection such as Richard Lewontin, David Sloan Wilson, and Elliot Sober suggest that there are many phenomena (including altruism) that gene-based selection cannot satisfactorily explain. The philosopher Mary Midgley, with whom Dawkins clashed in print concerning The Selfish Gene,^[42][43] has criticised gene selection, memetics and sociobiology as being excessively reductionist^[44] and suggests that the popularity of Dawkins' work is due to factors in the Zeitgeist such as the increased individualism of the Thatcher/Reagan decades.^[45]

In a set of controversies over the mechanisms and interpretation of evolution (the so-called 'Darwin Wars'),^[46][47] one faction was often named after Dawkins and its rival after the American palaeontologist Stephen Jay Gould, reflecting the pre-eminence of each as a populariser of pertinent ideas.^[48][49] In particular, Dawkins and Gould have been prominent commentators in the controversy over sociobiology and evolutionary psychology, with Dawkins generally approving and Gould generally being critical.^[50] A typical example of Dawkins' position was his scathing review of Not in Our Genes by Steven Rose, Leon J. Kamin and Richard C. Lewontin.^[51] Two other thinkers on the subject often considered to be allied to Dawkins are Steven Pinker and Daniel Dennett; Dennett has promoted a gene-centred view of evolution and defended reductionism in biology.^[52] Despite their academic disagreements, Dawkins and Gould did not have a hostile personal relationship, and Dawkins dedicated a large portion of his 2003 book A Devil's Chaplain posthumously to Gould, who had died the previous year.

Dawkins' book The Greatest Show on Earth: The Evidence for Evolution expounds the evidence for biological evolution.^[53] All of his previous works dealing with evolution had assumed its truth, and not explicitly provided the evidence to this effect. Dawkins felt that this represented a gap in his oeuvre, and decided to write the book to coincide with Darwin's bicentennial year.^[54]

Meme[link]

Dawkins coined the word meme (the behavioural equivalent of a gene) as a way to encourage readers to think about how Darwinian principles might be extended beyond the realm of genes.^[55] Indeed, it was intended as an extension of his "replicators" argument, but it took on a life of its own in the hands of other authors such as Daniel Dennett and Susan Blackmore. These popularisations then led to the emergence of the field of memetics, from which he has distanced himself.^[56]

Dawkins' memes refer to any cultural entity that an observer might consider a replicator of a certain idea or a complex of ideas. He hypothesised that people could view many cultural entities as capable of such replication, generally through exposure to humans, who have evolved as efficient (although not perfect) copiers of information and behaviour. Memes are not always copied perfectly, and might indeed become refined, combined or otherwise modified with other ideas, resulting in new memes, which may themselves prove more, or less, efficient replicators than their predecessors, thus providing a framework for a hypothesis of cultural evolution, analogous to the theory of biological evolution based on genes.^[57]

Although Dawkins invented the specific term meme independently, he has not claimed that the idea itself was entirely novel,^[58] and there have been other expressions for similar ideas in the past. For instance, John Laurent has suggested that the term may have derived from the work of the little-known German biologist Richard Semon.^[59] In 1904 Semon published Die Mneme (which appeared in English in 1924 as The Mneme). This book discussed the cultural transmission of experiences, with insights parallel to those of Dawkins. Laurent also found the term mneme used in Maurice Maeterlinck's The Life of the White Ant (1926), and has highlighted the similarities to Dawkins' concept.^[59] Author James Gleick describes Dawkins’ concept of the meme as "his most famous memorable invention, far more influential than his selfish genes or his later proselytizing against religiosity".^[60]

Criticism of creationism[link]

Dawkins is a prominent critic of creationism (the religious belief that humanity, life and the universe were created by a deity,^[61] without recourse to evolution^[62]). He has described the Young Earth creationist view that the Earth is only a few thousand years old as "a preposterous, mind-shrinking falsehood",^[63] and his 1986 book, The Blind Watchmaker, contains a sustained critique of the argument from design, an important creationist argument. In the book, Dawkins argued against the watchmaker analogy made famous by the 18th-century English theologian William Paley in his book Natural Theology. Paley argued that, just as a watch is too complicated and too functional to have sprung into existence merely by accident, so too must all living things, with their far greater complexity, be purposefully designed. Dawkins shares the view generally held by scientists that natural selection is sufficient to explain the apparent functionality and non-random complexity of the biological world, and can be said to play the role of watchmaker in nature, albeit as an automatic, nonintelligent, blind watchmaker.^[64]

Dawkins at the 34th annual conference of American Atheists, 2008

In 1986 Dawkins participated in an Oxford Union debate, in which he and English biologist John Maynard Smith debated Young Earth creationist A. E. Wilder-Smith and Edgar Andrews, president of the Biblical Creation Society.^[b] In general, however, Dawkins has followed the advice of his late colleague Stephen Jay Gould and refused to participate in formal debates with creationists because "what they seek is the oxygen of respectability", and doing so would "give them this oxygen by the mere act of engaging with them at all". He suggests that creationists "don't mind being beaten in an argument. What matters is that we give them recognition by bothering to argue with them in public."^[65]

In a December 2004 interview with American journalist Bill Moyers, Dawkins said that "among the things that science does know, evolution is about as certain as anything we know." When Moyers questioned him on the use of the word theory, Dawkins stated that "evolution has been observed. It's just that it hasn't been observed while it's happening." He added that "it is rather like a detective coming on a murder after the scene... the detective hasn't actually seen the murder take place, of course. But what you do see is a massive clue... Huge quantities of circumstantial evidence. It might as well be spelled out in words of English."^[66]

Dawkins has ardently opposed the inclusion of intelligent design in science education, describing it as "not a scientific argument at all, but a religious one".^[67] He has been referred to in the media as "Darwin's Rottweiler",^[68] a reference to English biologist T. H. Huxley, who was known as "Darwin's Bulldog" for his advocacy of Charles Darwin's evolutionary ideas. He has been a strong critic of the British organisation Truth in Science, which promotes the teaching of creationism in state schools, and he plans—through the Richard Dawkins Foundation for Reason and Science—to subsidise the delivery of books, DVDs and pamphlets to schools, in order to counteract what he has described as an "educational scandal".^[69]

Advocacy of atheism[link]

Dawkins lecturing on his book The God Delusion, 24 June 2006.

Dawkins is an outspoken atheist and a prominent critic of religion. In an interview with Thomas Bass for a book published in 1994 he described himself as a "fairly militant atheist".^[70] In 1996, when asked if he would prefer to be known as a scientist or a militant atheist, he replied "Bertrand Russell called himself the Passionate Sceptic. It's aiming high, but I'll shoot for that."^[71] Dawkins is an Honorary Associate of the National Secular Society,^[72] a vice-president of the British Humanist Association (since 1996),^[7] a Distinguished Supporter of the Humanist Society of Scotland,^[73] a member of the Secular Coalition for America advisory board,^[74] a Humanist Laureate of the International Academy of Humanism,^[75] and a fellow of the Committee for Skeptical Inquiry.^[76] In 2003 he became a signatory of the humanist manifesto Humanism and Its Aspirations, published by the American Humanist Association.^[77] As a result of his advocacy of atheism, Dawkins has sometimes been described as a vocal, militant rationalist,^[78][79] and as "the UK's Chief Atheist".^[80]

Dawkins believes that his own atheism is the logical extension of his understanding of evolution^[81] and that religion is largely incompatible with science.^[82] In his 1986 book The Blind Watchmaker, Dawkins wrote:

An atheist before Darwin could have said, following Hume: "I have no explanation for complex biological design. All I know is that God isn't a good explanation, so we must wait and hope that somebody comes up with a better one." I can't help feeling that such a position, though logically sound, would have left one feeling pretty unsatisfied, and that although atheism might have been logically tenable before Darwin, Darwin made it possible to be an intellectually fulfilled atheist.^[83]

In his 1991 essay "Viruses of the Mind" (from which the term faith-sufferer originated), he suggested that memetic theory might analyse and explain the phenomenon of religious belief and some of the common characteristics of religions, such as the belief that punishment awaits non-believers. According to Dawkins, faith − belief that is not based on evidence − is one of the world's great evils. He claims it to be analogous to the smallpox virus, though more difficult to eradicate.^[84] Dawkins is well known for his contempt for religious extremism, from Islamist terrorism^[85] to Christian fundamentalism; but he has also argued with liberal believers and religious scientists, from biologists Kenneth Miller^[86] and Francis Collins^[87] to theologians Alister McGrath and Richard Harries.^[88] Dawkins has stated that his opposition to religion is twofold, claiming it to be both a source of conflict and a justification for belief without evidence.^[89] However, he describes himself as a "cultural Christian",^[90] and proposed the slogan "Atheists for Jesus".^[91]

Following the 11 September 2001 attacks, when asked how the world might have changed, Dawkins responded:

Many of us saw religion as harmless nonsense. Beliefs might lack all supporting evidence but, we thought, if people needed a crutch for consolation, where's the harm? September 11th changed all that. Revealed faith is not harmless nonsense, it can be lethally dangerous nonsense. Dangerous because it gives people unshakeable confidence in their own righteousness. Dangerous because it gives them false courage to kill themselves, which automatically removes normal barriers to killing others. Dangerous because it teaches enmity to others labelled only by a difference of inherited tradition. And dangerous because we have all bought into a weird respect, which uniquely protects religion from normal criticism. Let's now stop being so damned respectful!^[92]

Dawkins has especially risen to prominence in contemporary public debates relating science and religion since the publication of his 2006 book The God Delusion, which has achieved greater sales figures worldwide than any of his other works to date. Its success has been seen by many as indicative of a change in the contemporary cultural zeitgeist, central to a recent rise in the popularity of atheistic literature.^[93][94] The God Delusion was praised by among others the Nobel laureates Sir Harold Kroto and James D. Watson and by psychologist Steven Pinker.^[95] In the book, Dawkins suggested that atheists should be proud, not apologetic, because atheism is evidence of a healthy, independent mind.^[96] He sees education and consciousness-raising as the primary tools in opposing what he considers to be religious dogma and indoctrination.^[16][97][98] These tools include the fight against certain stereotypes, and he has adopted the term Bright as a way of associating positive public connotations with those who possess a naturalistic worldview.^[98] Dawkins notes that feminists have succeeded in arousing widespread embarrassment at the routine use of "he" instead of "she". Similarly, he suggests, a phrase such as "Catholic child" or "Muslim child" should be considered just as socially absurd as, for instance, "Marxist child": children should not be classified based on their parents' ideological beliefs.^[98] According to Dawkins, there is no such thing as a Christian child or a Muslim child, as children have about as much capacity to make the decision to become Christians or Muslims as they do to become Marxists.^[96]

In January 2006 Dawkins presented a two-part television documentary The Root of All Evil?, addressing what he sees as the malignant influence of religion on society. The title itself is one that Dawkins disliked, noting that religion shouldn't be regarded as the root of all evil.^[99] Critics have said that the programme gave too much time to marginal figures and extremists, and that Dawkins' confrontational style did not help his cause and exhibited similarities with the approaches of religious fundamentalists more than with the approaches of the dispassionate, analytic approach of 'hard' science;^[100][101] Dawkins rejected these claims, citing the number of moderate religious broadcasts in everyday media as providing a suitable balance to the extremists in the programmes. He further remarked that someone who is deemed an "extremist" in a religiously moderate country may well be considered "mainstream" in a religiously conservative one.^[102] The unedited recordings of Dawkins' conversations with Alister McGrath and Richard Harries, including material unused in the broadcast version, have been made available online by the Richard Dawkins Foundation for Reason and Science.^[103]

Dawkins' work has been controversial, and a number of Christian thinkers have responded to it. For example, Oxford theologian Alister McGrath (author of The Dawkins Delusion and Dawkins' God) maintains that Dawkins is ignorant of Christian theology and therefore unable to engage religion and faith intelligently.^[104] In reply, Dawkins asks "do you have to read up on leprechology before disbelieving in leprechauns?",^[105] and − in the paperback edition of The God Delusion − he refers to the American biologist PZ Myers, who has satirised this line of argument as "The Courtier's Reply".^[106] Dawkins had an extended debate with McGrath at the 2007 Sunday Times Literary Festival.^[107]