Carl Sagan – A Life In The Cosmos

It’s incredible to think that it's more than fourteen years since the world lost a most remarkable astronomer, pioneer exobiologist and populariser of science - Carl Sagan.

A son of Jewish immigrants to the United States, Sagan was born in Brooklyn, New York, where he spent his childhood developing an interest in astronomy. A high achiever, he studied physics at the University of Chicago, gaining a master’s degree in 1956, before being awarded a doctorate there in 1960 in astronomy and astrophysics. He then lectured at Harvard University until 1968, when a move to Cornell University in Ithaca, New York beckoned. In 1971 this became a full-time professorship that included the directorship of the Laboratory for Planetary Studies. He also took an increasing interest in pioneering exo-biology and publicising the Search for Extraterrestrial Intelligence (SETI). During this period, he also became an Associate Director of the Centre for Radio Physics and Space Research at Cornell, and later was instrumental in lecturing at Cornell in scepticism and critical thinking.

Such an academic career would have been amazing in itself, but Sagan had been heavily involved in the US space program since the 1950s -- including his celebrated briefings of the Apollo astronauts before their flights to the Moon. However, of utmost interest to this most talented of scientists was planetary science and the increasing number of NASA robotic missions to neighbouring planets in the solar system. Indeed, he was responsible for many of the biology and chemistry laboratory packs placed on these unmanned probes. He also gained worldwide attention for his idea of placing gold-anodised unalterable universal messages, onto unmanned spacecraft destined to leave our solar system. These included Pioneer 10 and 11, launched in 1972 and 1973 respectively. In the albeit slim hope of these emissaries of mankind one day millions of years from now being located by extraterrestrial intelligence, the plaques were developed further, and along with the Golden Record of sounds of the earth, were again attached to the Voyager unmanned probes launched to investigate the outer solar system in 1977.

Sagan’s scientific research achievements and discoveries about other planets in our solar system, and their applicability to the Earth were immense. He was, for example pivotal to the discovery of Venus’s high surface temperature of 500 degrees Celsius and its crushing atmospheric pressure, this data being gained from the planet’s radio emissions. Whilst working for NASA at the Jet Propulsion Laboratory at Pasadena he was involved in the design and management of the first Mariner missions to Mars. Mariner 2 would later confirm Sagan’s analysis that Venus was indeed the Earth’s Evil Twin, and not the balmy paradise which was the conjecture of many scientists in the early 1960s. Through his studies of Venus and its runaway greenhouse effect, he identified man-made carbon dioxide emissions on the Earth as a possible cause of climate change. He was also a staunch opponent of the Cold War arms race, justifying his views by research into the effects of nuclear winter – one of the after effects of a full superpower nuclear exchange.

Sagan was the first scientist to hypothesise that Saturn’s moon Titan may possess lakes and oceans of liquid methane or ethane, and that the reddish haze of this moon’s atmosphere was a result of complex organic molecules. This would be confirmed after Sagan’s death by the Cassini probe and associated Huygens Titan lander. He also hypothesised that Jupiter’s moon Europa had a subsurface ocean of liquid water. This he thought possible, under an ice sheet in such low temperatures, because of the heat from Europa’s volcanism, resulting from the massive tidal stresses on the moon due to its close proximity to the gas giant.

His other achievements included work on the seasonal changes on the surface of Mars, including what he correctly identified as windstorms, at a time when many other scientists regarded them as vegetation. His interest in the possibility of extraterrestrial life led him into demonstrating how amino acids, the building blocks of life, can be produced by irradiating basic organic chemical compounds found in abundance in our solar system’s gas giant planets and their many moons. In conjunction with this he also assisted Dr Frank Drake (who formulated the now famous Drake Equation complete with its now decreasing number of variables for calculating the total number of intelligent extra-terrestrials capable of interstellar radio communication in the Milky Way) in writing the Arecibo Message, beamed to interstellar space in 1974, with the aim of informing extraterrestrials about Earth. Sagan was also a founder member of the Planetary Society, an organisation that promotes the active involvement of the worldwide public in planetary exploration and new forms of propulsion such as the Solar Sail.

However, above all, it is Sagan’s immense legacy of science advocacy, and in particular his many ground-breaking public science education publications and documentaries that earned him worldwide public acclaim, in particular Cosmos: A Personal Voyage. Heavily influenced by the success of the Jacob Bronowski’s BBC series The Ascent of Man (1974), PBS commissioned Sagan to produce (along with collaborators Steven Soter and Ann Druyan) this epic documentary series.

As one of the true popularisers of astronomy and science, Sagan relished the opportunity. The result was an inspiring, lavish and totally exquisite thirteen-part series, first broadcast in 1980 and viewed (according to the NASA Office of Space Science) by over 600 million people in over 60 countries worldwide – still the most-watched science documentary series ever. It thus comes as little surprise that the series was immediately awarded an Emmy and Peabody Award. As Druyan notes it is a fitting tribute to the foresight of her late husband, that even the recent digital re-mastering of the entire series required little updating regarding factual content.

The power of Cosmos lies in Sagan’s inspirational delivery of its main contention -- our oneness with the Cosmos. To view Cosmos is one of the most spiritually uplifting experiences, made all the more remarkable because it is a science series. For example, it explains how we, and all the creatures with which we share the Earth are all made of star stuff, from the elements in our own bodies including the calcium in our bones, the iron in our blood, to the carbon in each and every cell. Whilst the first light elements such as hydrogen and helium were formed at the time of the Big Bang nucleosynthesis, the heavier elements, such as nickel, copper, iron and oxygen were synthesised in the nuclear furnaces of long-dead stars, many of which became supernovae. The heavy chemical elements, were a product, once this first generation of stars had used all of their hydrogen nuclear fuel.

Sagan movingly sums up the whole process in the introduction to both the series and the book that in effect, the Cosmos, is all that is, all that has been, and all that ever will be. Through a process of nearly fourteen billion years of cosmic evolution, and later Darwinian Natural Selection, humans evolved and became a very special part of this cosmos. In effect, through mankind, the cosmos has evolved its very own intelligence and consciousness – star stuff harvesting star light and enquiring about its own existence.

In taking complex scientific theories and concepts such as Special Relativity, Darwinian Selection and Atomic Theory and presenting them in a correct, yet readily understandable form, without the need for complex mathematics, Sagan realised the importance for mankind’s future wellbeing of the public’s understanding of science and involvement in what both he and Druyan termed the Scientific Enterprise. Despite making scientific knowledge easily accessible to a the general public he received many criticisms from the scientific elite, many no doubt jealous of his deserved celebrity status, or annoyed at his attacks on vested interests. His explanation in Cosmos of Special Relativity, “Journeys in Space and Time”, remains one of the most eloquent and understandable introductions to the subject, enticing the reader or viewer to delve deeper.

The issue of scientific advocacy repeatedly appears throughout Sagan’s many books including Pale Blue Dot: A Vision of the Human Future in Space and The Demon Haunted World: Science as a Candle in the Dark. He uses the example of the destruction of Ptolemy II’s Great Royal Library in Alexandria in 415AD, and the murder of Hypatia, its last librarian and the world’s first female mathematician by the mob, as an example of what can happen when knowledge is kept secret by a ruling elite. The result of the destruction of the Great Library, and the Ionian civilisation centuries before was the loss of knowledge of incalculable value amassed over a thousand years, and the start of a dark epoch in human history. This epoch was characterised by mysticism, bigotry, racial and religious extremism and hatred and witchcraft, ending only with Copernicus, Johannes Kepler, Tyco Brahe and Galileo Galilei and Giordano Bruno (many of whom even in the seventeenth century were being persecuted by the Roman Catholic Church, and indeed in the case of Bruno murdered for the heretic act of speculating about a galaxy brimming with exo-planets and extraterrestrials).

Neither has the threat to our present civilisation from ignorance evaporated. In Pale Blue Dot, Sagan notes how we (in western civilisation) have contrived to produce advanced societies based primarily on high technology and science where only a small fraction of the population has any scientific knowledge. This, according to Sagan, coupled with the growth in religious extremism, racial hatred, superstition, the supernatural and seudoscience is a recipe for disaster, and one, given our advanced weaponry will sooner, or later, explode in our faces.

Sagan appeals to scientists and science enthusiasts alike to become advocates for the subject. Instrumental in both the Viking landings on Mars in the summer of 1976 and the Voyager missions to the outer planets in the 1980s, he uses the Voyager 1 “Pale Blue Dot” photograph of the Earth as an example. Senior administrators at NASA did not want to waste resources re-configuring the spacecraft to take a photograph of the Earth from six billion kilometres. Sagan appealed above their heads citing the immense public interest of the photograph. After all, he stated the US public was funding NASA and as paymasters they had a right to witness what would become one of the most famous photographs of all time – the Earth as a pale blue mote of dust suspended in a sunbeam. It is by no means certain that humanity will avoid self-destruction either through environmental degradation or through weapons of mass destruction (and there are more than adequate quantities still available).

In both Cosmos and Pale Blue Dot, Sagan speculates that simultaneously to gaining interstellar communications ability, civilisations also gain atomic physics, and perhaps more-or-less immediately use nuclear weapons to engage in self destruction. Perhaps this is why we have not been visited by ET. Or, as Sagan says, perhaps ET is constantly dealing with its self-generated environmental degradation. But above all else, Sagan, in all his science advocacy is an optimist and believes that humanity can and will rise above the challenges posed by our very nature, the juxtaposition of our technology with beliefs, and the disasters that nature can throw at the Earth, such as asteroid impacts. It will be achieved, he says, by the same scientific enterprise with its proven successful method of critically independently verified facts and theories, not by superstitions, ufology or mysticism.

Scientists have made astonishing leaps forward in the past 400 years, for example in technology and medical sciences -- infact in virtually every area of modern advanced industrial society. Compare that, Sagan says, with what other areas of human thought and belief have provided in improving the lives of the populace. Instead of wanting to believe in something amazing -- do something amazing. Add to the body of human knowledge about the cosmos, or show a child the Andromeda Galaxy. Show them how the light, the fastest thing we know has taken a staggering 2.5 million years to reach our eyes! Inspire them to naturally develop that innate human curiosity about science and the universe in which we live.

Sagan powerfully states in Cosmos that it is the birth rite of every child, of every generation to gain knowledge about their place in the universe, and to critically evaluate such knowledge and facts. To do less would risk being taken in by the first charlatan character, perhaps even on a societal scale – and there are plenty of examples of that in human history. Extraordinary claims do indeed require extraordinary evidence. As Sagan says, there are no authorities in science, it’s a totally democratic subject, relying on verified facts, and theories that are readily falsifiable. Yet it’s also a very human and creative subject. No one knows from which ranks the next Einstein, or Newton will come.

No article on Carl Sagan would be complete without mentioning Contact. The book, upon which the movie that followed it is largely based, was written by Carl Sagan and published in 1985. Some of Sagan's character traits are evident in the main character, Ellie Arroway, and the novel serves as an enthralling platform in which he encapsulates ideas surrounding many of his life's interests, especially the first contact with extraterrestrials. A film adaptation of Contact, starring Jodie Foster, was released in 1997. Without spoiling the film, for those yet to view it, Dr. Ellie Arroway (Jodie Foster), after years of searching for "the truth" in radio astronomy, finds conclusive radio astronomical proof of intelligent aliens, who have been receiving our first radio and television broadcasts since the early twentieth century. The aliens send plans of how the human race can construct a machine of immense technology using wormholes (the scientific theory behind this was confirmed as correct by Sagan's fellow scientist and colleague, Kip Thorne). Ellie's role in the movie is juxtaposed with that of Palmer Joss (Matthew McConaughey). He has spent his life searching for "the truth" through faith in God. This first radio "contact", means that both Ellie and Palmer, and indeed, everyone on Earth, are forced to challenge their own assumptions. In the inevitable first contact, will humankind be able to find a compromise between science and belief? If any movie is worth watching – this is it!

Tragically, Sagan died in December, 1996, after a long fight with myelodysplasia, a rare form of bone cancer at the comparatively young age of 62. A voice of reason and science in a world where superstition and mysticism are once again in the ascendancy, he was one of those talented individuals humanity, at a critical juncture in its history, could least afford to lose. The challenge is for his readers, viewers and students to pick up the gauntlet.

If you ever endeavour to rationalise why you are so avidly interested in astronomy and cosmology, re-visit Carl Sagan’s vast astronomical bequest to the public. He succinctly explains why we tingle at the thought of the cosmos and long to leave the Earth -- it’s in our genes to return to the stars. More importantly you realise the immense importance of science, and of inspiring your children, or the young generation generally with the subject. Yet you are probably depressed at the degradation and sensationalisation of science documentaries on television. If this is the case, and you get the chance, buy the Cosmos DVD set, or buy the book or any of Sagan’s other publications. All of his books are readily available from public libraries. Allow this potent master of the Cosmos into your homes and let him inspire your families, friends and importantly youngsters in taking an interest in science.

The proof of Sagan’s potent teaching and inspiration lies in many of his students and colleagues who have gained leading roles in space exploration. These include Carolyn Porco, a leading US planetary scientist,  Director of the Hayden Planetarium, New York and PBS-Nova presenter Neil deGrasse Tyson, and Steve Squyres, principal investigator of the NASA Mars Exploration Rovers, Spirit and Opportunity. On a personal level, had it not been for a chance viewing of the PBS Cosmos series a five years ago, you would not be reading this now, and neither would you see myself or my son, thoroughly relishing our visits to our local planetarium, or our nights out under the stars with our trusty old telescope!

Bibliography
Communication with Extraterrestrial Intelligence (MIT Press, 1973)
Mars and the Mind of Man (Harper &  Row, 1973)
Broca's Brain: Reflections on the Romance of Science (Ballantine Books,1974)
Other Worlds (Bantam Books, 1975)
Murmurs of Earth: The Voyager Interstellar Record (Random House, 1977)
The Dragons of Eden: Speculations on the Evolution of Human Intelligence (Ballantine Books, 1980)
Ann Druyan, co-author, Shadows of Forgotten Ancestors: A Search for Who We Are (Ballantine Books, 1993)
Pale Blue Dot: A Vision of the Human Future in Space. Random House, (November 1994
The Demon-Haunted World: Science as a Candle in the Dark (Ballantine Books, 1996)
Ann Druyan co-author, Billions and Billions: Thoughts on Life and Death at the Brink of the Millennium (Ballantine Books, 1997)
The Varieties of Scientific Experience: A Personal View of the Search for God, 1985 (Gifford lectures, Penguin Press, 2006).

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