EDITED BY YERVANT TERZIAN AND ELIZABETH BILSON
A helpful guide to the accomplishments of Carl Sagan in research, science education, the space program, and public policy
4 stars out of 5 stars
In the summer of 1966, just before I graduated with a PhD degree, I spent two months as a graduate student participating in a summer program at the National Radio Astronomy Observatory in Charlottesville, Virginia. The main part of this program was a series of invited lectures by renowned astronomers, mostly from external institutions but also several from in-house, to lecture on topics of their specialties. A young professor from Harvard named Carl Sagan was among the external speakers. Other than the phrase “Venus is hell”, I did not remember what else he said, but his lively and flamboyant lecturing style did leave an impression on me to this day.
It turned out that Harvard did not grant him tenure, and his nomination to the National Academy of Science was also rejected. These elite institution/Academy apparently believed that a science populariser cannot be a serious scientist. A phrase “The Sagan Effect” was coined for this misguided hypothesis – misguided since analyses of Sagan’s publications (there were several hundred) suggest that his research accomplishments were comparable to Academy members and colleagues who were less involved in public outreach.
Sagan joined Cornell University in 1968. By then I already graduated and missed the opportunity to attend his classes. He had not, however, vanished from my life. I was one of the 500 million people in 60 countries who watched his 1980 television series Cosmos: A Personal Voyage. I own the book Cosmos, which was on New York Times Best Seller List for 72 weeks. I was aware that he and Frank Drake designed the Pioneer Plagues and that he was instrumental in conceiving and implementing the Golden Record, a phonograph record containing a broad sample of Earth’s sounds, languages, and music. The Golden Record was carried by both Voyager I and Voyager II into outer space in 1977, with the hope that they would someday be intercepted by intelligent extraterrestrial beings. I was aware that Sagan won the Pulitzer Prize for “Dragons of Eden“, and I watched the movie CONTACT based on his novel of the same title. The movie, unfortunately, was not completed before he died.
And who would not be in awe watching Carl Sagan’s speech about the Pale Blue Dot, the photo of Earth taken by Voyager I on February 14,1990 before it left the solar system and sailed onto interplanetary space.
In October 1994, Cornell University hosted a symposium to celebrate Carl Sagan’s sixtieth birthday. The lectures were organized around Sagan’s work, in four areas. They are: Planetary Exploration; Life in the Cosmos; Science Education; and Science, Environment, and Public Policy. There were 26 Speakers, from academia, NASA, as well as other organizations. To my surprise, there was also a stage magician turned scientific skeptic who extensively challenged paranormal and pseudoscientific claims. Another surprise was that, Thomas Gold, who recruited Carl Sagan to Cornell, was not among the speakers. Frank Press, who was President of the National Academy of Sciences, spoke at the end with a “Speech in Honor of Carl Sagan”. It was ironic that the Academy rejected Sagan’s membership nomination, which presumably occurred before Press’ presidency.
The book “Carl Sagan’s Universe”, edited by Yervant Terzian and Elizabeth Bilson, contained all the lectures, including a public lecture by Carl Sagan, entitled “The Age of Exploration”. I offer below brief comments on several of the speeches. I should point out that, in my opinion, among the long list of distinguished speakers, the jewel goes to Carl Sagan, whose remarks about the "pale blue dot" were for the ages.
Ann Druyan - Does Science Need to Be Popularized?
Ann Druyan was Secretary, Federation of American Scientists. She co-wrote the 1980 PBS documentary series Cosmos, hosted by Carl Sagan, whom she married in 1981. In her speech, she stated that we can have science without democracy, but she wondered if we can hope to have democracy without science. She equated asking the question “should science need to be popularized” to asking the question “should we have a democracy”. In her opinion, no one did better to popularize science than Carl Sagan. Among the interesting stories she told was the porter at Union Station in Washington, D. C., who had watched Cosmos, stopped Carl from trying to give him a tip by saying “Put away your money, Dr. Sagan. You gave me the universe. Now let me do something for you.”
There were also these perceptive statements in her speech: “Science is the great baloney-detection kit that we desperately need because our greatest strength as a species is also our greatest weakness. We are imaginative, but we are also terrible liars. We lie to keep power, We lie to keep other people from getting power. We lie to make ourselves feel special…..”
Hats off to Ann Druyan!
James Hansen - Public Understanding of Global Climate Change
James Hansen was Director, NASA Goddard Institute for Space Studies. He was among the first scientists who brought attention to Climate Change, with data showing Global Warming trend and its relation to human activities. He told the story that, after he testified to a Senate Committee on 1988 on this subject, the first time the public heard about his message about Global Warming was through the TV program Jeopardy, in which the message was incorrectly stated. Subsequent media coverage focused on repeating what was said on Jeopardy. His experience illustrated the importance and the difficulty of communicating with the public about scientific topics, and the need for more folks like Carl Sagan who were doing it so effectively.
James Randi - Science and Pseudosciences
The affiliation of James Randi was listed as Plantation, Florida. I have not heard of him before. When I found out he was a stage magician, I was surprised that he was included among the speakers. When I learnt that he extensively challenged paranormal and pseudoscientific claims, his inclusion began to makes some sense. I further learned that he was the author of books and won numerous awards, including the 2012 Lifetime Achievement Award of the American Humanist Association. This certainly revealed my ignorance and opened my eyes. I wonder whether he and Carl Sagan were friends. I hope the James Randi Educational Foundation would debunk the misinformation about Covid which are flooding social media nowadays.
Kip S. Thorne - Do the Laws of Physics Permit Wormholes for Interstellar Travel and Machines for Time Travel?
Kip Thorne was Richard Feynman Professor of Theoretical Physics at California Institute of Technology. Earlier in his career, he was Andrew D. White Professor at Large at Cornell from 1986-1992. He shared the 2017 Nobel Prize in Physics with Rainer Weiss and Barry C. Barish "for decisive contributions to the LIGO detector and the observation of gravitational waves".
In his lecture, Thorne told the story that Carl Sagan asked his help to make sure that what he wrote about interstellar travel in the novel “Contact” was all correct with Einstein’s theory of general relativity. This led Thorne’s research group to direct its efforts to answer the question: “What constraints do the laws of physics place on an infinitely advanced civilization?” This research led to the conclusion that interstellar travel was not possible through black holes but may be possible through worm holes, provided that exotic matters are available to keep the worm holes open. An exotic matter is “a material that violates the averaged null energy condition” (does this phrase makes more sense to you?). Travel backward in time appears to be not possible. Sagan had to revise the original manuscript accordingly.
Thorne explained all this general relativity/quantum field theory stuff with words and diagrams. He did not include a single equation, which could give the impression that the theory is understandable to a lay person. In fact, it is highly incomprehensible, but it is an extraordinary experience reading it through nonetheless.
Roald Sagdeev - Highlights of the Russian Planetary Program
I was familiar with the name, as Sagdeev was a plasma physicist. Plasma physics was my research area from 1965 to about 1980. He was a former director of the Space Research Institute of the USSR Academy of Sciences and a science advisor to Soviet President Mikhail Gorbachev. In 1989, he was appointed Professor of Physics at the University of Maryland. He married Susan Eisenhower, granddaughter of President Eisenhower, in 1990. The coupled divorced in 2007. Sagdeev was the recipient of the 2003 Carl Sagan Memorial Award, and the James Clerk Maxwell Prize for Plasma Physics (2001) of the American Physical Society.
In the speech, Prof. Sagdeev recounted the efforts of the Russian Planetary Program and attempts for Russia-US co-operation. He opened his speech with the historic fact that the Orbital Station Mir was launched during Soviet time. While orbiting the earth, the cosmonauts on board discovered that it was already the Russian epoch. Prof. Sagdeev pointed out, amusingly, that it was probably the first experiment with living Einsteinian observers who discovered that the clocks in the orbit were moving in a different way.
Frank Drake - Extraterrestrial Intelligence: The Significance of the Search
Frank Drake was listed as Professor of Astronomy, University of California, Santa Cruz. For 20 years, from 1964-1984, he was Professor of Astronomy at Cornell University. He was a founding member of the Search for Extraterrestrial Intelligence (SETI) Institute. He conceived the Drake Equation, a probabilistic argument used to estimate the number of active, communicative extraterrestrial civilizations in the Milky Way Galaxy. One learns from the lecture that speculating about extraterrestrial intelligence started as early as the 1920s, but it was only in the 1950s and early 1960s when people started to approach the matter in a proper scientific way. The first such paper in print was by Philip Morrison and Guiseppe Cocconi at Cornell, entitled "Searching for Interstellar Communications" on the 21 cm Hydrogen line, which turned out to be of vital importance in the SETI program. The paper was published in the Journal Nature in 1959. Drake also mentioned that one of the first books on this subject was by S. Shklovskii and Carl Sagan, entitled “Intelligent Life in the University”, published in 1966. Drake described in detail the sophisticated technologies and the world-wide efforts to detect extraterrestrial intelligence.
Carl Sagan - The Age of Exploration
As I mentioned already, the jewel of the speeches was the public lecture Sagan gave in the Interlude. Sagan said that it was natural for early humans to regard the earth as the center of the solar system and the Universe, since it was an observable fact that the sun rose in the east and set in the west everyday. With the invention of the telescope, this notion had to go, but the sun was still regarded as the center of our galaxy and the Milky Way was thought to be the only galaxy in the universe. Later, this too had to go, when astronomers were able to observe that the sun was among numerous stars in the Milky Way, and it did not occupy a central location in the galaxy. Moreover, the Milky Way was one among billions and billions of galaxies. Sagan called the revelations of these discoveries a series of demotions for human beings. The biggest demotion so far was due to Charles Darwin, who essentially proposed that all of us Earth beings are relatives. A future possible big demotion could be when we succeeded in communicating with extraterrestrial intelligence. To many in the audience, all this was rather upsetting, prompting someone to ask “What did all the demotions left us?” Sagan’s answered was “On our own”.
Sagan’s speech included remarks about “The pale blue dot”, a phrase coined by him to describe the Earth in the photo taken by Voyager I before it left the solar system and sailed into interplanetary space. The speech was made into a video in YouTube. Someone (I am sure not Sagan) gave it the appropriate title “The Greatest Speech about Humanity”. The link to the video is:
Anyone who has not watched the video should do so.
Frank Press opened his speech in Honor of Carl Sagan this way: “Thomas Huxley once said: ‘A man of science after the age of 60 does more harm than good’. It may apply to some of us but Carl is one of the few exceptions!”
It was an enormous loss to humanity that Carl Sagan died two years after his sixtieth birthday.
In conclusion, the book is a helpful guide to the accomplishments of Carl Sagan in research, science education, the space program, and public policy, the latter exemplified by his tireless effort to educate the public and governments about the unimaginable consequences of nuclear winter if nuclear weapons were used in wars. Above all, he instilled in us the realization that it is our responsibility “to deal more kindly with one another and to preserve and cherish the pale blue dot, the only home we’ve ever known.”
Pioneer 10 Plaque
The Golden Record cover shown with its extraterrestrial instructions. Credit: NASA/JPL
(Source: Carl Sagan's Universe, Cambridge University Press 1997)
Bình luận