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The Darkened Cosmos: A Tribute to Carl Sagan

Special Tribute

The Editors

Skeptical Inquirer Volume 21.2, March / April 1997

One of the world’s strongest and most eloquent voices for science and reason has been silenced forever. Carl Sagan died December 20 in a Seattle hospital at the age of sixty-two after a two-year battle with the bone marrow disease myelodisplasia. One of the world’s great popularizers of science, Sagan was a preeminent scientist, educator, author, skeptic, and humanist. He was also a founding member and fellow of the Committee for the Scientific Investigation of Claims of the Paranormal (CSICOP).

Sagan’s award-winning 1980 TV series Cosmos and best-selling book by the same name turned the ebullient planetary astronomer into an international celebrity. The thirteen-part TV series explored scientific understanding of fifteen billion years of cosmic evolution from the Big Bang to the origin of life and human consciousness.

Sagan’s presentation of his subject was so fascinating and comprehensible that Cosmos attracted an audience of over half a billion people in sixty countries. The book from the series spent seventy weeks on the New York Times best-seller list, including fifteen weeks at number one.

Sagan’s career as a popularizer began in the early 1970s when he started publishing science books aimed at a lay audience and made his first of twenty-five appearances on NBC’s The Tonight Show. His book The Dragons of Eden: Speculations on the Evolution of Human Intelligence won the Pulitzer Prize for Literature in 1978.

He continued his work as a popularizer of science and critical thinking right up until the end of his life. In his article in the March 10, 1996, Parade magazine, titled “In the Valley of the Shadow,” he spoke movingly of his illness and his attitude toward death as a nontheist and skeptic: “I would love to believe that when I die I will live again, that some thinking, feeling, remembering part of me will continue. But much as I want to believe that, and despite the ancient and worldwide cultural traditions that assert an afterlife, I know of nothing to suggest that it is more than wishful thinking.

“The world is so exquisite with so much love and moral depth, that there is no reason to deceive ourselves with pretty stories for which there’s little good evidence. Far better it seems to me, in our vulnerability, is to look death in the eye and to be grateful every day for the brief but magnificent opportunity that life provides.”

Despite Sagan’s fame as popular writer and TV personality, his main career was in science and academia. From 1971 until his death, Sagan was professor of astronomy and space science and director of the Laboratory for Planetary Studies at Cornell University. His main research interests, resulting in hundreds of journal articles, were in planetary atmospheres, the greenhouse effect on Venus, the origin of life on Earth, and the possibilities of extraterrestrial life and intelligence.

Five years ago the American Astronomical Society presented Sagan its Masursky Award for “his extraordinary contributions to the development of planetary science. . . . As a scientist trained in both astronomy and biology, Dr. Sagan has made seminal contributions to the study of planetary atmospheres, planetary surfaces, the history of the Earth, and exobiology. Many of the most productive planetary scientists working today are his present and former students and associates.”

He contributed to the Mariner, Viking, Voyager, and Galileo planetary exploration missions that opened new planetary worlds to our view and helped devise the interstellar messages carried aboard the Pioneer 10 and 11 and Voyager 1 and 2 spacecraft. NASA twice awarded him medals, one for Exceptional Scientific Achievement and one for Distinguished Public Service.

Said NASA administrator Dan Goldin at Sagan’s death: “As much as any scientific figure of our time, Carl described for an entire generation—the generation of the space age—the true wonders of the universe around us.”

“Sagan understood the need to bring science into American living rooms, to show its relevance to our everyday lives, and to share the excitement and discovery,” said Neal Lane, director of the National Science Foundation.

In 1994, the National Academy of Sciences, the nation’s most august group of scientists, presented Sagan its Public Welfare Medal, given to “honor extraordinary use of science for the public good.” Said Academy president Bruce Alberts: “In the public view, Carl Sagan’s name may be associated more with science than that of any other living U.S. scientist. This award clearly honors a very distinguished individual who has played a critical role in promoting the understanding of science worldwide.” One of Sagan’s colleagues at Cornell University, Yervant Terzian, said Sagan was “the best teacher of science in the world.”

Sagan actively supported the work of CSICOP and was a great fan of Skeptical Inquirer. In 1987 at CSICOP s conference in Pasadena, he was given CSICOP s In Praise of Reason Award. In 1994 CSICOP created the Isaac Asimov Award in honor of Asimov’s extraordinary contributions to science and humanity. The first recipient of this award was Carl Sagan. It was presented at the 1994 CSICOP Conference in Seattle. The award is in recognition of an individual who throughout his or her life has shown outstanding commitment and ability in communicating the achievements, methods, and issues of science to the public.

When told that the first Asimov award would be presented to Carl Sagan, Janet Asimov said, “There is no one better qualified for the CSICOP Isaac Asimov Award than his good friend and colleague Carl Sagan. Isaac was particularly fond of Carl. He was also in awe of Carl’s genius, and proud that he was so adept at communicating science to the public through speaking, writing, and the visual media.”

In his keynote address at the Seattle conference, Sagan spoke to an audience of more than a thousand. He spoke about his love of science and the importance of the popularization of science: “Science is still one of my chief joys. The popularization of science that Isaac Asimov did so well—the communication not just of the findings but of the methods of science—seems to me as natural as breathing. After all, when you’re in love, you want to tell the world. The idea that scientists shouldn’t talk about their science to the public seems to me bizarre.”

Paul Kurtz, chairman of CSICOP, said, “Carl Sagan was one of the leading scientific skeptics in the world and a critic of antiscientific and irrational attitudes, and perhaps the leading proponent of the scientific outlook and the methods of science. His untimely loss is deeply felt by the scientific and academic community.”

In his last book, The Demon-Haunted World: Science as a Candle in the Dark, Sagan wrote:

I worry that, especially as the Millennium edges nearer, pseudoscience and superstition will seem year by year more tempting, the siren song of unreason more sonorous and attractive. Where have we heard it before? Whenever our ethnic or national prejudices are aroused, in times of scarcity, during challenges to national self-esteem or nerve, when we agonize about our diminished cosmic place and purpose, or when fanaticism is bubbling up around us—then, habits of thought familiar from ages past reach for the controls.

The candle flame gutters. Its little pool of light trembles. Darkness gathers. The demons begin to stir.

Said Kurtz: “I am afraid the world has just become a bit darker.”

Carl Sagan is survived by his wife Ann Druyan; two former wives; his sister, Carl Sagan Greene; five children; and a grandson. He will be fondly remembered and sorely missed. Donations in Carl Sagan’s name can be made to: The Children’s Health Fund of New York (317 East 64th St., New York, NY 10021) or The Carl Sagan Memorial Fund (The Planetary Society, 65 N. Catalina Avenue, Pasadena, CA 91106).

Skeptical Inquirer invited friends and colleagues of Carl Sagan and others whose lives he touched to share their thoughts about his life and work with our readers. Here are some of those tributes. More will appear in our next issue.

Richard Dawkins

In my review for The Times of London of The Demon-Haunted World, I mentioned a chapter heading of Carl Sagan’s Cosmos. “Who Speaks for Earth?” I went on that it was “a rhetorical question that expects no particular answer, but I presume to give it one. My candidate for planetary ambassador, my own nominee to present our credentials in galactic chancelleries, can be none other than Carl Sagan himself. He is wise, humane, polymathic, gentle, witty, well-read, and incapable of composing a dull sentence.”

In the Financial Times this year, I described him as “a beacon of dear light in a dark world of alien abductions and ‘real-life X-files,’ of psychic charlatans and New Age airheads, of fatcat astrologers giggling all the way to the millennium.” I met him only once, so my feeling of desolation and loss at his death is based entirely on his writings. Carl Sagan was one of the great literary stylists of our age, and he did it by giving proper weight to the poetry of science. It is hard to think of anyone whom our planet can so ill afford to lose.

Richard Dawkins is the Charles Simonyi Professor of the Public Understanding of Science at Oxford University. His latest book is Climbing Mount Improbable (W. W. Norton, New York).

Arthur C. Clarke

I was very sad to hear of Carl’s untimely death. Though I was aware of his medical problems, recent reports had indicated that he was making a steady recovery.

My friendship with Carl, who in Japan would be regarded as a national treasure, began more than thirty years ago: for my account of our adventure at the 1964 New York Worlds Fair, see Roddy McDowall’s Double Exposure, Take Three: A Gallery of the Celebrated with Commentary by the Equally Celebrated (William Morrow, 1992).

Carl was a superstar in that difficult art where many otherwise capable and brilliant scientists are miserable failures: popular science communication. The book and TV series Cosmos still remain one of the most widely distributed and admired efforts to interpret the momentous findings and achievements of the space age.

In his later books, such as Pale Blue Dot and The Demon-Haunted World, he took on—ably and daringly—the pseudoscience and nonscience that rots the American mind, ranging from creationism and alien abductions to beliefs in astrology. At a time when The X-Files and its clones dominate the airwaves, Carl’s loss is doubly tragic.

I ended my tribute to Carl in Double Exposure by recalling a more recent encounter I had via satellite with him and Stephen Hawking: “After a quarter of a century, Carl hasn’t mellowed much. I’m sure he’d still be happy to give God a little helpful advice on how the universe ought to be designed.”

I only wish I could believe that he’s doing this right now.

Arthur C. Clarke’s science fiction novels and stories and his nonfiction writing on space technology and the future have been influencing audiences and policymakers worldwide for half a century.

Martin Gardner

Carl Sagan was one of those rare working scientists who was also a superb science writer and who believed it was his duty to enlighten the general public about the wonders of the universe and of life on one of its smallest planets. I recall a time when he delivered a paper at a meeting of the American Association for the Advancement of Science denouncing Velikovsky as an ignoramus. He was roundly criticized by his colleagues. They said he had demeaned his reputation as a serious astronomer by wasting time on so frivolous a matter.

Now that irrational beliefs are more prevalent than ever, scientists are finally beginning to understand what Sagan tried to tell them. They have a responsibility to combat the increasing flood of bogus science in bookstores and on magazine stands, on movie and television screens, and even in courses offered by top universities. Carl’s last book, The Demon-Haunted World, is a brave and powerful indictment of America’s dumbing down, a vigorous plea for better science education. Carl, R.I.P. You fought a great fight and left the world healthier and wiser than it would have been without you.

Martin Gardner’s latest books are The Night Is Large: Collected Essays 1938-1995, and Weird Water and Fuzzy Logic: More Notes of a Fringe-Watcher.

David Morrison

Carl Sagan did more than any other individual in this century to bring science to the public in a way that was consistently honest, thoughtful, and humane. Carl was a natural teacher, always ready to explain and defend his ideas. I never saw him asked a question that he was not willing to answer in a serious, thoughtful way, and I never saw him face a question that he had not already considered. He believed that everyone could understand science and should be interested in it. His faith in the power of human thought did not falter, even in the face of massive misinformation and unreason.

Carl was immensely influential in guiding public opinion on science, especially on planetary exploration. He participated in and chronicled the history of the space age, thoughtfully considering the issues of why we explore and how we can use our knowledge of the planets, and of the balance between robotic and human exploration strategies. Carl often pointed out that ours is the only generation to experience the transformation of the planets from mere specks of light into real worlds, each with its own unique geology, atmosphere, and even potential for life. When he was a young assistant professor his popular public lectures at Harvard College Observatory were entitled “Planets are Places,” a commonplace idea now, but a step of imagination then. His final book on space science, The Pale Blue Dot, summarized the exploration of eight planets and more than fifty moons, placing our own blue Earth in its cosmic perspective. He will be remembered best as the person who interpreted this generation of exploration for the public, and who helped create a new way to think about our own planet.

Carl’s final book, The Demon-Haunted World, was a passionate defense of scientific skepticism and an attack on pseudoscience. The fact that this book was considered controversial and received less acclaim than many of his expository writings about science demonstrates how badly such works are needed. Understanding the nature of science and the way scientists view the world is more difficult for most people than absorbing and appreciating the facts of science. I fear that we will miss Carl’s presence in this area more than any other. His uncompromising integrity and the respect with which the public viewed him were bulwarks against the tides of unreason. Let us use Carl’s memory as a weapon in the struggle against pseudoscience, recalling the way he worked out problems as well as the eloquence with which he articulated the discoveries of science.

David Morrison, Director of Space at NASA Ames Research Center, was one of Sagan’s first graduate students.

James Randi

Another of my giants has fallen. When Dick Feynman died in 1988, it was a terrible blow. In 1992, Isaac Asimov left us, and I was devastated. Now that Carl Sagan is gone, I feel even more deserted by my very limited spectrum of heroes. I feel anger and sorrow equally. Every four years, it seems I lose a valuable part of my existence.

My first meeting with Carl was when we lunched in New York City and he gave me his candid opinion of my first book, The Magic of Uri Geller. He found it, he said, rather poorly organized and lacking in documentation. I had to agree that he spoke sooth, and explained that I’d bashed it together within six weeks as a rush job for the publisher. It was felt that Gellers career was pretty well over, only two years after he first appeared on the scene, because the public would soon tire of the novelty. Therefore, my book was expected to have a very short life. Carl and I had many opportunities after that to recall just how wrong we’d been, in both those respects. But he provided me with a powerful comment on the book.

Carl was one hell of a speaker. Audiences always reacted positively to his message, and he handled questions—even very belligerent ones—with calm and incisiveness. I always envied his control in the face of idiocy and his patience with the uninformed.

As a teacher, he constantly instructed his students to “look into it” and “find out,” rather than merely telling them solutions. I observed him with awe as he worked at Cornell when I was privileged to be consulted about the design of his Critical Thinking course. His constant good humor, sincere smile, and very expressive hands and face, all made him a fine teacher and public speaker, a convincing explainer of the beauty and importance of science.

Carl was a trifle annoyed that he had been credited with saying, “Billllyuns and billllyuns of stars!” He claimed that he’d never uttered the words, and that Johnny Carson had first used them in a parody of him. Carl’s extensive exposure on the Carson show and his electric presence made him into one of the highest-paid lecturers on the circuit, and literally a household word. In my extensive travels, I’ve always earned jealous admiration from my association with Carl and with Martin Gardner. One Swiss scientist told me, “I’d kill just to meet either of them!” He hyperbolized only a bit, I’m sure.

I once discussed the Cosmos series with Carl, and with a mighty sigh he told me he’d had no idea of what the director and editors of the material intended to do with the many shots of him staring off at far horizons while shielding his eyes with his hand to his brow. “One more shot of me standing in a cardboard spaceship and musing over the future,” he growled, “and I’d have had a minor fit of artistic revolt!” Even with the several minor failings of the series—all of editing and direction—Cosmos was by far one of the most effective vehicles of the time for bringing science to public. I know of many persons who were first made aware of the true nature of science by watching and enjoying Cosmos.

In The Demon-Haunted World Carl expresses, in one of the most moving and compelling selections from his work, his deep concern over the increasing temptation of pseudoscience, superstition, and unreason, especially as the new millennium approaches: “Whenever our ethnic or national prejudices are aroused, in times of scarcity, during challenges to national self-esteem or nerve, when we agonize about our diminished cosmic place and purpose, or when fanaticism is bubbling up around us—then, habits of thought familiar from ages past reach for the controls.” When these take over, “The candle flame gutters. Its little pool of light trembles. Darkness gathers. The demons begin to stir.”

Well, dammit, one of those candles has gone out. The burden now falls on us to provide as much light as we can generate, to banish the darkness and make sure it docs not triumph over us. If you ever doubt that your voice is needed to bring a little rationalism or truth to others who may need it, re-read these words of Carl Sagan. The demons must not be permitted to rise. We owe that much to the memory of this fine man.

James Randi, conjuror and investigator of psychic claimants, is author of Flim-Flam! and An Encyclopedia of Claims, Frauds, and Hoaxes of the Occult and Supernatural.

Jill Tarter

All of us working on the search for extraterrestrial intelligence (SETI) owe a special debt of gratitude to Carl Sagan; sadly, we can no longer look forward to repaying that debt in person. The best possible form of repayment would have been to present the extraordinary evidence required to support the extraordinary claim that we share our universe with other intelligent creatures from worlds beyond Earth. Such evidence still eludes us. Its discovery (we hope) lies in the future, and Carl Sagan, the man, now lies in the past. But Carl Sagan, the ultimate skeptic, will go forward into the future. Each student he taught, each colleague he worked with and challenged, each person who has read his final book, The Demon-Haunted World, will have experienced firsthand the best possible example of what it means to embrace the scientific method. To the extent that they follow this example and pass it along to their students and colleagues, they insure that Carl’s passion for science and his message about the difference between evidence and belief will go forward into the future, to the benefit of all.

Jill Tarter is director of the SET/ Institutes privately funded Project Phoenix in Mountain View, California, and a CSICOP fellow.

Paul Kurtz

Carl Sagan was not only a good friend, but one of the strongest proponents of CSICOP on the national and international scene. A charter fellow of CSICOP, Carl was ever willing to criticize claims of the paranormal.

I can attest to his personal courage and independence. In 1975, I organized a protest among scientists—the first of its kind—to the widespread growth of astrology and issued a statement, “Objections to Astrology,” co-authored by Harvard astronomer Bart Bok and science writer Lawrence Jerome, and endorsed by 186 leading scientists from the National Academy of Sciences, including 19 Nobel Prize winners. Carl declined to sign it, because of its tone. Although a strong critic of astrology, he thought the statement would be ineffective. The next year, however, when we founded CSICOP, he accepted my invitation to become a fellow and joined with enthusiasm.

The following year I invited him to respond to an article by Immanuel Velikovsky in a special issue of The Humanist I was editing on the topic, “Controversies on the Borderline of Science.” His article, tided “Analysis of Worlds in Collision,” sharply criticized Velikovsky. I remember how angry Velikovsky became with me for giving space to Sagan. For years Carl had been receiving vituperative attacks from the cult of Velikovsky; they had never forgiven him for his criticism of Velikovsky at an AAAS meeting in 1974. But Carl never wavered in his readiness to attack junk science and paranormal claims.

Carl volunteered his services to CSICOP time and again. He was the keynote speaker at two of our national conferences—in Pasadena in 1987 and Seattle in 1994—and we bestowed our In Praise of Reason and Isaac Asimov awards on him. And he took every occasion that arose to defend skepticism as essential to the process of scientific inquiry. One article he wrote for Parade magazine that extolled CSICOP brought in thousands of new subscribers. In his personal correspondence and meetings with me, he was effusive in his praise, but he was also ready and able to offer constructive criticism of us and make suggestions about topics that we should investigate. He always insisted that we be fair and impartial in our analyses.

At his sixtieth birthday celebration in 1994, of which Barry Karr, executive director of CSICOP, and I attended, Carl again criticized pseudoscience and defended constructive skepticism. Although Carl Sagan was a resolute proponent of the scientific outlook and scientific methodology throughout his life, he was open to creative new theories on the frontiers of science; but he insisted that these be corroborated by the evidence. For example, although he argued that the search for extraterrestrial life is a great adventure for the human spirit, he was skeptical of those who proclaimed that UFOs were from outer space.

In the last months and weeks before his death, he hoped that the latest therapies of medical science might stem his illness and save his life. Alas, he did not survive. His death is a profound loss to CSICOP and the entire skeptical movement.

Paul Kurtz is founder and chairman of the Committee for the Scientific Investigation of Claims of the Paranormal.

Alan Hale

I first met Carl Sagan at a DPS (Division of Planetary Sciences/American Astronomical Society) meeting during the late 1980s, when I stopped him after he’d given a paper and asked if he could stand to meet one more graduate student “who had always wanted to meet Carl Sagan.” Despite the fact that he was on his way to an impending engagement, he took a few moments of his time to discuss some details of his paper with me. Since that time I had the privilege of meeting and chatting with Dr. Sagan at other conferences, and while the moments I had with him were usually quite brief, they are moments I treasure.

Carl Sagan’s tireless and dedicated work toward answering some of the most basic questions as to who and what we are served as a significant inspiration to me to take up the search myself and make my own contributions toward understanding these questions. Through his work on the Viking and Voyager missions, and his efforts to understand the formation of solar systems and the very origins of life itself, he has helped enormously in unraveling the mysteries of the universe around us. We have all benefited from the humbling, yet awe-inspiring, view of the universe his work has helped reveal to us.

All his scientific achievements notwithstanding, I believe Dr. Sagan’s most important contribution lies in his dedication to sharing that view of the universe with the lay public of our society. In a world awash in scientific illiteracy and pseudoscientific nonsense, his was a solid and unmistakable voice of science and reason. As we enter the twenty-first century facing a host of scientific and technological challenges that we are only now beginning to fathom, his was a voice that we could ill-afford to lose. It is incumbent upon those of us who remain to carry on the torch of reason, and to bring about the vision of the future that Carl Sagan instilled in the minds of those who so admired him.

Alan Hale is co-discoverer of Comet Hale-Bopp and is director of the Southwest Institute for Space Research in Cloudcroft, New Mexico.

Christopher Chyba

Everywhere in the universe Carl Sagan looked, he saw possibilities for life. But consider several of Carl’s most important contributions to planetary science. At the outset of his career, he demonstrated that a runaway greenhouse effect would raise Venus’ temperatures to hundreds of degrees above the boiling point of water—making life (as we know it) nearly impossible there. He later went on to show that the seasonal color changes on Mars that had been observed from Earth were probably due to global dust storms, rather than (as had been previously proposed) an expanding and receding seasonal wave of vegetation. Finally, in later research, he discovered the “early faint-Sun paradox,” demonstrating that, assuming our own Sun had evolved like a typical G-class star, it would have been substantially fainter at the time of the origin of life on Earth, so the early Earth would have been much colder. Without a higher greenhouse effect on early Earth, or some other mechanism, surface temperatures would have been too cold for liquid water to exist, and therefore inhospitable for life. A similar problem would have existed for early Mars.

Each of these discoveries shares one characteristic: It makes life or the origin of life in our own solar system seem significantly less likely than would otherwise have been the case. These results obviously flew in the face of Carl’s well-known enthusiasm for the possibility of extraterrestrial life. But they were the conclusions to which the data and his research led him. Again and again as a scientist, he followed his own admonition to be especially skeptical when one’s deepest hopes or fondest wishes were at stake.

Christopher F. Chyba received his Ph.D. under Carl Sagan at Cornell University. He is now an assistant professor of planetary science at the University of Arizona.

Leon M. Lederman

I can think of no major problem influencing humanity, in personal lives, in communities, the nation, and the planet, that is not, in some deep way, influenced by our scientific age and which cannot be illuminated by a grasp of science—science as a way of thinking, science as a clarifier of issues. Carl Sagan understood this and used his great talents as an erudite and vibrant communicator. He set an awesome example for all of us. Scientists must embed communication as an essential part of their métier. The greater the scientist, the more important is this ethic.

By his own passion for planetary science, by his active concerns in national science policy, and by his unique and heroic efforts in public understanding, Carl Sagan has set new standards for the conduct of scientists.

We need a Carl Sagan Award for Public Understanding of Science. Friends of Carl, industry, and concerned citizenry should be able to assemble the endowment for a substantial annual award to call attention to and fan the flame that Carl Sagan kindled.

Leon M. Lederman is director emeritus of the Fermi National Accelerator Laboratory and a 1988 Nobel laureate in physics.

Clifford A. Pickover

I mourn the passing of Carl Sagan with great sadness. Sagan helped us understand the universe both through his television series Cosmos and his many publications describing worlds beyond our own as well as the worlds within ourselves. As I grew up, Carl Sagan was an inspiration, and now that my own popular science books are taking off, I feel an emptiness that I can’t share new projects with him. Strangely, just today I received galley proofs of my book The Alien IQ Test in which I had a humorous chapter devoted to the abduction of Carl Sagan by aliens. Sadly, the humor now seems misplaced, and I’ve asked Basic Books to remove the reference to Dr. Sagan before the book’s publication this spring.

These days perhaps one measure of a science-popularizer’s greatness is the number of wonderful web pages devoted to him or her on the World Wide Web. There are thousands of sites mentioning Carl Sagan or discussing his ideas. These sites, along with his books, will continue to reverberate long after his death. (I have gathered together links to some these thought-provoking Sagan sites on my home page at

We are all molded and remolded by those who have inspired us, and though their lives may pass, we remain, nonetheless, the products of their influence. No one as fascinating as Sagan can ever cross the path of our destiny without leaving some mark upon it forever.

Clifford A. Pickover, of the IBM Watson Research Center, is the author of a dozen popular science books including Black Holes: A Traveler’s Guide and Keys to Infinity.

John Allen Paulos

Carl Sagan and I corresponded a few times in recent years, and his death prompted me to reread his letters. In one written just after a Washington Post article had discussed the snideness sometimes directed toward scientific popularizers, he asked about my experiences with the phenomenon. With characteristic simplicity he wondered, “I’m interested in understanding this very peculiar sense that these subjects (science and mathematics) are to be kept for an elite.” Sagan reached expansively beyond the elite. Through his pioneering and exuberant efforts, a whole generation has glimpsed some of the power and beauty of scientific ideas and become wary of the ubiquitous quackery that too many scientists leave uncontested for fear of being labeled a popularizer. This fear is based on a confusion. The opposite of a popularizer is not an eminent researcher (which, of course, Sagan also was) but an unpopularizer (a common breed of scientist, unfortunately). Carl Sagan will be missed by many of us, and retroactively perhaps, if there are sentient beings elsewhere, by many others as well.

John Allen Paulos is a CSICOP fellow and the author of Innumeracy and A Mathematician Reads the Newspaper.

Chip Denman

I was an undergraduate at Cornell, where Sagan taught. Even in the mid ’70s, Sagan was widely known to the public as an eloquent advocate of science and reason. Even before Cosmos, he was recognized from his appearances on The Tonight Show with Johnny Carson, an avid amateur astronomer. And Sagan was also regarded as one of the best teachers on campus. I regret that I did not take his ASTRO 101; my friends who did enjoyed it and him a great deal.

At one time I considered pursuing astronomy as a field of study. Our undergraduate astronomy club held a meeting in which Sagan came to talk about how best to prepare for a career in astronomy. There were no more than twenty of us in a generic classroom. Sagan draped himself across the desk at the front of the room and just chatted casually. His advice: don’t take undergraduate astronomy courses—those were mainly meant for dabblers, to please the masses. Instead, he urged, study math and physics, the essential tools for serious astronomy. So I did, as a double major. I eventually realized that I was enjoying the math more than the physics, and so, one course short of the physics requirement, I dropped physics and doubled up on the math. I filled the hole in my schedule with courses in probability and statistics—and almost at once I found that this was the focus I had been searching for.

So, I did not become an astronomer. But Sagan’s friendly advice to this young undergraduate indirectly brought me to my chosen field of mathematical statistics. I owe him much for that.

Others sometimes criticized Sagan for being a “popularizer”—as if that were a bad thing! I wish science had more who were even half as effective. As I became publicly active in the promotion of science and skeptical thinking, Sagan continued to inspire. Shortly after the founding of the National Capital Area Skeptics in 1987, I attended my first national conference sponsored by CSICOP. Sagan was the keynote speaker; his words were full of urgency, tempered with humor. I have found myself reaching back and quoting him when I’ve needed a nugget of skeptical thought that would make sense to a reporter or an audience. Few had his ability to make skepticism sound so sensible, natural, and necessary.

The public no longer has him to reach out to them from their Sunday papers, where few scientists dare to tread, and to thrill them with the excitement of good science and good thinking. I am sad for that.

Chip Denman is manager of the Statistics Laboratory at the University of Maryland, where he also teaches “Science and Pseudoscience” for the University Honors Program. He is past-president of the National Capital Area Skeptics.

Shawn Carlson

I didn’t know Carl Sagan personally, but like many of his admirers, I sullenly followed the progress of his terrible illness. After seeing his last appearance on the news show Nightline, when he was physically weak and displaying the devastating effects of chemotherapy, I guessed that the end would come soon. And yet when the sad news of his death did arrive a few weeks later, it moved me far more than I ever thought it would.

We all know of Sagan’s accomplishments as a researcher and of his unparalleled stature as the “showman of science” (to quote Time magazine). But if historians mark only these, they will be selling his legacy far short. The ultimate measure of a great life lived is the impact one has had on other lives. And by this accounting, Carl Sagan was a great man indeed. His life and works will ultimately contribute to far more good in the world than even he could have known.

I was still an undergraduate when Cosmos, perhaps Sagan’s greatest masterpiece, first aired. It was quite unlike any documentary I had ever seen. Sagan’s passion for science shined through. And his eloquence at translating scientifically obtuse concepts for the masses was, for me, inspirational. I loved it! Indeed, Cosmos helped inspire me to become a science writer. As I see it, every column I write for Scientific American propagates a little more of Sagan’s influence.

I’m confident that dozens of other science writers were equally inspired, and for all of their work Sagan deserves a little credit. Further, there must be hundreds of working scientists whose passion for science was sparked, or at least helped along, by Sagan’s zeal. And with hundreds of millions of viewers worldwide, Sagan’s Cosmos advanced science literacy tremendously. Indeed, if Clarence (the sprightly angel from It’s a Wonderful Life) could show us what the world would have been like had Carl Sagan never been born, I’m quite sure we would find it a markedly poorer place; less literate with far fewer eyes turned skyward.

Shawn Carlson writes “The Amateur Scientist” department for Scientific American magazine and is the founder and executive director of the Society for Amateur Scientists.

Nicholas Humphrey

I think of Carl Sagan in the summer of 1987 at the Moscow conference of the International Physicians for the Prevention of Nuclear War. He spoke out with his matchless combination of authority and passion against the self-perpetuating absurdities of the Cold War, the folly of the arms race, and the irrationality of the policy of nuclear deterrence. He had been doing some sums: by his calculation, the total defense expenditure by the United States since the end of World War II would by now be enough to buy up every saleable object on the North American continent—every building, every work of art, every TV set, every automobile, every silk stocking, and every stand of timber. Meanwhile half the world was starving. Sagan’s quiet anger at the situation he described, and his own determination to use all his powers to change it, spread to everyone in his large audience—and perhaps it also spread beyond. Gorbachev received a delegation from the conference that same day and listened thoughtfully as they pressed for the Soviet Union to take the initiative toward disarmament. Within a few months the process had begun. Sagan was a model of the socially responsible scientist. He loved truth, beauty, and life, whether at the level of science or public policy, and hated superstition, narrow-mindedness, and false prophecy. He was one of those rare people capable not only of interpreting the world but of changing it: and he did both.

Nicholas Humphrey, author of Consciousness Regained: A History of the Mind and Soul Searching, is a professor of psychology at the New School for Social Research, New York.

Daniel R. Alonso

I am a federal prosecutor. I also was a student of Carl Sagan’s at Cornell in the fall of 1986. Just last week, a friend and I were discussing which living American we admired most. Without hesitation, I named Carl Sagan, which might have struck my friend as odd. After all, it’s not often that a lawyer reserves his greatest admiration for a scientist.

To me, it made perfect sense. As a federal prosecutor, I am very much in the business of skepticism. It’s my job not to take things at face value, but instead to investigate in a logical and thorough manner, hoping to arrive finally at the truth. It also made sense because I was fortunate to have known briefly the man I admired so much, as I was his student. The skills Carl Sagan taught me—both personally and through his writings—have served me well in my chosen profession.

In the fall of 1986, I told Professor Sagan that I wanted to be a prosecutor and asked him to recommend me for law school. He graciously agreed, but not before dissecting my intended career choice in ten different ways and ruminating about it for a while. As those who knew him much better than I did surely know, this was his usual way, and it had its intended effect in this case of really making me think about where I was headed.

In my work today, I do quite a bit of dissecting and ruminating of my own. Thinking about Professor Sagan ten years later, I’m pleased that he was there to share my career choice with me and impart me with skills I needed to succeed. Now, as I continue down my own path, I think fondly of my Cornell professor, who was taken from us all—lawyers, scientists, and many others—long before his time.

Daniel R. Alonso is an assistant United States attorney in New York City

Javier E. Armentia

I remember, in 1980, that man on the screen, waving his hands, explaining astronomy as no one before had done on TV. I was studying physics, and he convinced me to become an astronomer. So he did for many of my colleagues and many of my students. Later I discovered the writer, the skeptic, the scientist . . . and he again convinced me of many things. No doubt we will miss Carl Sagan. But I know that his work and his life have been of great influence to many people: we, those who must continue working to popularize science, skepticism, and critical thinking.

Javier E. Armentia is president of Alternativa Rational a las Pseuaociencias (ARP) and director of Planetario de Pamplona, Pamplona, Spain.

Barry Williams

Australian Skeptics

I am sure that all Australian skeptics and all who experienced the feelings of wonder and love of science that he inspired will feel deeply the loss of Carl Sagan. He was truly a frontline warrior in the battle against ignorance, superstition, and the “armies of the night.” He was far too young to have left the scene and, although I never had the pleasure of meeting him, I will miss him.

Swedish Skeptics

Carl Sagan’s books have had a major impact in Sweden, both through translations and in the original English. There are few other writers of popular science who have reached as many enthusiastic readers in our country. To us in the Swedish Skeptics, his writings have been a constant source of inspiration. And they will continue to be so, for Carl Sagan was a man whose influence will last much longer than his own life.

For the board of the Swedish Skeptics. Per-Olof Hulth (chairman) and Sven Ove Hansson.

Michael D. Sofka

I had the great pleasure of hearing Carl Sagan speak in 1994 at the State University of New York at Albany. This was just before the publication of Pale Blue Dot, and his talk included a short reading from that book about the Voyager photograph of Earth. In this photograph, taken at Sagan’s insistence, Earth was a single pixel—a pale blue dot. “On [that dot] everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. . . . The Earth is a very small stage in a vast cosmic arena. Think of the rivers of blood spilled by all those generals and emperors so that, in glory and triumph, they could become the momentary masters of a fraction of a dot.” Carl Sagan saw the big picture.

More important, Carl Sagan was passionate about bringing the big picture to others. He was above all else a teacher, and I think an extraordinary one. After his talk, he sat down and for nearly an hour took questions from the audience. People lined up at the microphone to ask him about life on other planets, UFOs, the nature of science, and his views on religion. I sat there in awe.

Sagan looked perfectly at ease, in his natural environment, while answering those questions. And what questions they were! Many of them would have left me, and I suspect most readers, exasperated.

In The Demon-Haunted World Sagan said there is no such thing as a dumb question. He really believed this. Never did he show a lack of patience. Never once did he answer in a way that would make the questioner feel silly. He used each question to teach something. He might say that he didn’t know the answer, “but, let me tell you a related story,” and he would proceed to use the question as a jumping point for something better. The questioner always seemed satisfied. We skeptics lost a friend. But more, we lost a teacher.

Mike Sofka is president and co-founder of the Inquiring Skeptics of Upper New York.

Mark Boslough

One week before Carl Sagan’s death I visited a friend who is a professor at a large Southwestern university. We stayed up late that night talking about our research and sharing our gripes about the lack of support for science and the decay of education standards. My friend pointed out that his university prioritizes athletics above all else. Unfortunately, he said, that’s the sensible thing to do because such a large fraction of the applicants say that they are interested in the school because of its basketball team. He went on to tell me that when he was a post-doc at Cornell, many students there said they chose to apply because of Carl Sagan’s presence. We laughed at the irrelevance of both of these reasons, but later I remembered that Cornell was one of the few graduate schools to which I applied twenty years ago, shortly after the Viking mission landed robots on Mars. Science may never surpass basketball in the hearts of most school administrators, but the fact that a scientist can serve as a university recruiting device should give us all hope.

Mark Boslough is a physicist at Sandia National Laboratories, specializing in large-scale impacts.

Colin Groves

Carl Sagan was a leading scientist and one of the world’s foremost science communicators. His books and television programs were required fare for everyone interested in whatever branch of science. His successes in swaying doubters and waverers may relate both to his scientific rigor and to his deeply humane personality, which shone through his presentations and his writings. Scientists, educators, and skeptics everywhere will miss him greatly.

Colin Groves is in the Department of Archeology and Anthropology at Australian National University, Canberra, Australia.