Earth in Human Hands

by David Grinspoon

  He opened the Byurakan conference with his talk on “Multiplicity of Inhabited Worlds and the Problem of Interstellar Communication,” proclaiming,

  We are witnessing the inception of a new science, which occupies a boundary position between astrophysics, biology, engineering and even sociology.

  His logic was similar to that outlined at Green Bank, but his conclusions were less optimistic:

  Is intelligence an inevitable consequence of the long and tortuous evolutionary process of life forms? In my opinion, this is by no means so.

  He acknowledged the important work of Cocconi, Morrison, and Drake, but offered this critique of the American efforts:

  In our opinion, the main deficiency of Cocconi and Morrison’s idea and of its realization by Drake is in the assumption that the extraterrestrial civilizations are approximately on the same technological level as the Earth civilization. An inevitable conclusion which follows from this assumption is that the power of the receivers and the transmitters available to the alien civilizations is roughly the same as that of our equipment. But this proposition is inherently fallacious. It is well known that the time scale for the technological development of civilizations is exceedingly short. Consequently if there are civilizations in the Universe, they should greatly differ in the degree of their development. The great majority of civilizations should be technologically much more advanced than we are. We are only infants as far as science and technology are concerned.

  This notion that other civilizations would be much more highly advanced than ours was further emphasized by Nikolai Kardashev, a brash young astrophysicist and star student of Shklovsky’s. Only two years out of grad school at this meeting, Kardashev quickly established himself as a leading voice in global SETI, with bold ideas about the properties of advanced civilizations and how to find them. At Byurakan he proposed an enduring scheme (which became known as the Kardashev scale) for classifying technological civilizations.

  Kardashev presented an engineer’s view of the salient features of human history. The most quantifiable and, he thought, predictable quality of human societies over time was a steady increase in the use of energy. He proposed that this would be the nature of all technical civilizations in the universe. He showed that if our current annual increase in energy use continued at the same pace, that it would be less than a century before we would be utilizing the equivalent of all the solar energy available on Earth, only a few thousand years until we would expand into the solar system and consume the entire energy output of the Sun, and less than ten thousand years until our energy needs would rise to equal the output of all the stars in the galaxy. Based on these considerations, Kardashev proposed that all civilizations be classified into one of three types:

  • Type I civilizations are masters of their planets, and have learned to make use of the entire energy resources of their home worlds. Kardashev suggested that humanity was currently approaching type I.

  • Type II civilizations are masters of their solar systems. They would have expanded beyond their home planets and learned to use the entire energy resources of their home star.

  • Type III civilizations are masters of their galaxies. They have built an interstellar society and learned to harness the total energy resources of their entire galaxy of hundreds of billions of stars.

  Kardashev concluded that type I civilizations like our own should represent a brief transitional phase and thus would be relatively rare in the galaxy. Therefore (echoing Shklovsky’s complaint that the Americans were too eager to assume that ET was at our level), rather than listen for signals from type I civilizations, we should look for the massive engineering works of type II or III civilizations.

  British American physicist Freeman Dyson had been thinking along similar lines in 1960 when he published a paper in Science entitled “Search for Artificial Stellar Sources of Infrared Radiation.” Dyson proposed that an advanced civilization will ultimately surround its star completely with solar collectors to catch all its energy. For building materials, they might take apart fallow planets or use a multitude of asteroids, rearranging their solar system to be more biofriendly. Such a “Dyson sphere” surrounding a star need not be a single solid structure; it could be a cloud of smaller orbiting objects that, together, create a thick spherical shell, capturing all the star’s light in the service of life and civilization, and also providing plenty of surface area for living space and for whatever it is that superadvanced postplanetary civilizations do for fun.

  Dyson pointed out that if such structures existed, they would be observable across space at great distances. The high-energy solar radiation would be absorbed by the sphere, which would radiate at cooler infrared wavelengths. So, to find Dyson spheres created by advanced civilizations, we could search the galaxy for stars emitting an unusual excess of infrared radiation. Such a search for advanced societies by looking for their observable engineering projects carried an important advantage: they did not have to be sending out signals in order for us to discover their presence. The Soviet astronomers at Byurakan were aware of Dyson’s work. Kardashev suggested that Dyson spheres could be the observable architectural creations of type II civilizations. Science-fiction writers, picking up on this idea, have since generated many riffs on Dyson spheres and the varieties of Kardashev civilizations, helping us flesh out the possible paths of long-lived star cultures.6

  What the L?

  The most solid quantitative conclusion reached by the Soviets at Byurakan was the same as that reached by the Americans at Green Bank: that the distance between technical civilizations, and therefore the possible success of SETI, rests most crucially on the factor Drake called L, the average longevity. If L is small, because most technical civilizations last less than, say, one thousand years, then the equations show that communicating civilizations are few and far between, and the chances of SETI succeeding are nil. If, however, L is large, say, millions of years, then the galaxy should be full of chattering sentience, some quite near and easy to contact. Why? Imagine that technological intelligence existed on another planet for only, say, five hundred years. What chance would we have of ever observing it at random? That’s less than 0.0001 percent of a planet’s lifetime. Blink, and you’ve missed it. You’d have to stare at that world continuously and attentively for billions of years, or you’d never catch it in the act. It would be as if every cherry tree in Washington, DC, instead of blooming for a week or two each spring, flowered only once, randomly, for a few hours, during its fifty-year lifetime. If you stood watch over enough trees for long enough, you might see this occur, but if you observed just a few thousand trees for only a few minutes each (the equivalent of our current SETI searches), you’d almost surely know nothing about these episodes. Civilizations must make their presence known for many millennia, or they will be effectively invisible.* 7

  Although they did not use the word, the SETI scientists at Byurakan spent much time discussing the duration of the Anthropocene age, or its equivalent, on other planets. As Shklovsky put it in his talk,

  Another problem of cardinal significance is the duration of the Psychozoic era (the age of intelligent life) on any given planet. Here we are on fairly uncertain ground.

  He summarized some of the possible threats to survival of technical civilizations, including “self-destruction as the result of a thermonuclear holocaust or, in general, a discovery leading to unexpected and uncontrollable consequences,” or “a crisis connected with the creation of artificial intelligence.”

  It is hard to discuss the question of longevity without projecting our fears or expectations for our own future. Wondering whether other geek civilizations could survive for long periods is an excellent way for us to think, from a slightly different perspective, about our own prospects. If technological civilization is something that cannot last long, or usually does not, then are we doomed? Conversely, if we cannot imagine our own civilization navigating through our existential threats and surviving for many more thousands of year
s, why should we think that others typically can? If L is tiny, less than ten thousand years, then our attempt to hear the brief, ephemeral pings of scattered technical life before they fade out is akin to a search for the black box of a missing airplane in a vast ocean when the battery life of the transmitter is limited. Will anyone hear our ping before we fade to silence?

  In the early 1960s, while SETI was getting off the ground, the threat of nuclear annihilation was ever present. I was aware of it as a young kid growing up in those times. Bomb shelters and nuclear dread, along with the Space Race and the Beatles, were part of the landscape. My first political action, I am told, was being pushed in a stroller in a Ban the Bomb march in Boston when I was three years old. Because of my parents’ concern over radioactive iodine from atmospheric tests, my brother, Danny, and I didn’t drink fresh milk. Our breakfast cereal was served with powdered milk. With cruel irony, childhood leukemia took Danny’s life a decade later.

  During the tense peak of the Cuban Missile Crisis, my parents happened to be hosting a delegation of Soviet psychiatrists who were visiting Boston. Family lore has it that while they were making polite conversation in the living room, Danny and I were noisily roughhousing, crashing around in the bedroom above. When a particularly loud boom shook the ceiling, one of the visiting Russians remarked, “Sounds like an atome-ic bome!”

  My recurring childhood nightmare was of hiding in shelters, and trying to find my family, while the bombs fell. In the daytime, hopes and dreams of space and an enlightened future beyond Earth provided an escape and a direction.

  Even as the Cold War simmered, scientists across the Iron Curtain exchanged ideas about SETI. One international partnership, in particular, between Iosif Shklovsky and Carl Sagan, served as a catalyst and conduit for exchange between the separate but nearly parallel efforts. In 1962, for the fifth anniversary of Sputnik, Shklovsky published a magnificent SETI manifesto that drew penetrating conclusions about the evolution of life and civilizations on other worlds, and the prospects for using current and imagined science to find it. Its Russian title translates as Universe, Life, Mind. Upon learning of this work by the middle-aged Russian scientist, which contained ideas so similar to his own, the twenty-seven-year-old Carl Sagan, who had just begun his appointment at Harvard, wrote to Shklovsky and suggested a partnership. An English translation of Shklovsky’s book, significantly expanded by Sagan, was published in 1966 as Intelligent Life in the Universe, with Sagan and Shklovsky listed as coauthors. Many years later, in his posthumously published autobiography, Shklovsky wrote that he had misunderstood Sagan’s proposal, believing the offer was to have his book translated, with Sagan adding some introductory material. He was shocked when he saw the published work with both authors’ names printed on the cover. He also felt that the deal provided him with a best seller without any of the large royalties usually associated with one. As he summed it up,

  With his American business sense, Sagan effectively used the “Soviet-American book” as the springboard to a dynamic pop-science career, the apotheosis of which was his thirteen-part TV series Cosmos. Now he’s a very progressive millionaire, an active fighter against the threat of nuclear conflagration, and a scientist out on the rosily optimistic flank of the spectrum on the question of extraterrestrial civilizations. I have no grievance against this businesslike, cheerful, and congenial American: at my request he did all he could to help my brother when he fell sick in Paris.

  The two authors had never met in person when the book came out, and (though it might be hard for wired young people to imagine today) their communication was restricted to mailed packages and letters. Somehow this sub-light-speed exchange across the space between their worlds allowed a misunderstanding to persist. Yet, however clouded its origins, the book became, and remains, the Bible of SETI, bursting with prescient, penetrating insights and fearless speculations from these two luminous minds working together across the gulf of the Iron Curtain.

  Many of the most riveting ideas from this work, presented in a more casual, readable style, mixed with personal anecdotes and packaged with appealing and captivating artwork, formed the basis for The Cosmic Connection, Sagan’s first genuine best seller, which launched his career into orbit.

  Parts of the book read like a dialogue between the two astronomers, and although they saw eye to eye about the evolution of life, the universe, and almost everything, and shared a cosmic outlook on the human condition, each was a product of his own society, and there are places where the Cold War tension leaps off the page. Shklovsky declares that planets where capitalism exists will always be at great risk of self-destruction, and therefore advanced extraterrestrial civilizations will all be based on communism. Sagan responds:

  No one today lives in a society which closely resembles Adam Smith capitalism or Karl Marx Communism. The political dichotomies of the twentieth century may seem to our remote descendants no more exhaustive of the range of possibilities for the entire future of mankind than do, for us, the alternatives of the European religious wars of the sixteenth and seventeenth centuries. As Shklovsky says, the forces of peace in the world are great. Mankind is not likely to destroy itself. There is too much left to do.

  Their lively collaboration, embodied in their coauthored book, was the corpus callosum joining together the two hemispheres of SETI thought in a dangerously divided world.

  Each was critical of the excesses and failings of the other’s government, yet, steeped in awareness of possible self-destructing civilizations, each advocated for the abolition of nuclear arms. Shklovsky was especially scornful of the scientists who continued to assist the nuclear complex, referring to Edward Teller and his Soviet counterparts as “the cannibals.” In his memoir he spoke of being moved by a visit with Philip Morrison:

  I know personally one American scientist who displayed real heroism and civic courage in his relations with the cannibals. He is Phil Morrison, who is now one of America’s leading theoretical astrophysicists. Seriously ill, to all intents and purposes a cripple, even back in the far-off 1940s he realized that a scientist’s probity and honor are incompatible with the service of Beelzebub… Sitting with him at a table in a small Mexican restaurant in the old section of Albuquerque, some hundred miles from Los Alamos, I looked into his deep blue, childlike, clear eyes—the eyes of a man with a crystal-pure conscience—and my heart was uplifted.

  Sagan’s later work on nuclear winter, first published in 1983, fifteen months before Shklovsky’s death at age sixty-eight, is thought by many to have contributed to the end of the Cold War by rendering undeniable the futility of global nuclear conflict.

  Although they acknowledged other possibilities, Shklovsky and Sagan agreed that advanced civilizations were most likely to be peaceful, reasoning that any communicating civilizations out there must have been around much longer than we. Therefore, they would surely have learned to live with technology that, if accompanied by aggressive or warlike behavior, would have been incompatible with survival. They would have solved the existential problem humanity was facing, for the first time, with the Cold War. The continuing tension of that conflict, set against the optimism of SETI, formed a poignant backdrop for the first international SETI conference.

  After the success of their joint book, Sagan and Shklovsky decided it was time to bring their two communities together for an international meeting. The result was the Soviet-American Conference on Communication with Extraterrestrial Intelligence, jointly sponsored by the National Academies of Science of the USSR and the United States, and held, at Byurakan, in the same location as the first Soviet meeting (and thus sometimes referred to as Byurakan II).

  Sagan enlisted Drake and Morrison to help round up the delegation of American (and British and Canadian) scholars, which included a who’s who of late twentieth-century science, including visionary physicist Freeman Dyson, Nobel laureate Francis Crick (codiscoverer of the DNA double helix), and artificial intelligence pioneer Marvin Minsky. They also invited noted historian
William McNeill8 and others representing sociology, psychology, linguistics, and anthropology.

  The Soviet participants were organized by Shklovsky and Kardashev. Kardashev wanted to include only physicists and astronomers, as he felt that scholars from the humanities were merely “windbags,” but Shklovsky insisted that the Soviet delegation include linguists and philosophers. The proceedings, edited by Carl Sagan, and illustrated with candid black-and-white portraits shot by Phylis Morrison during the conference, include transcripts of the sometimes contentious discussions after the talks.

  Sagan began the meeting by writing the Drake equation out on a blackboard, and again it served as an agenda to organize the week of discussions, the topics beginning with the astrophysical and ending with the sociological. He presented estimates suggesting that humans would need to examine about one million stars to have a decent chance of finding one alien civilization, and “thus the probability of success of all efforts to date is < 10-4”—which was Carl’s nerdy way of opining that they would need to multiply previous efforts by more than 10,000 before success could be considered likely.

  There was much discussion of longevity and whether we could really say anything about the properties of long-lived civilizations. Historian William McNeill acted as an outsider to the SETI community and questioned many of the assumptions made by the astronomers. He pointed out the tragic misunderstandings that have occurred when human civilizations (which presumably have a lot more in common than we would with aliens) have encountered each other. Morrison countered that, given the distances and times involved, our encounters with alien civilizations would be inherently indirect, less like Cortés and the Incas and more like the way contemporary societies have learned from the culture of Ancient Rome. We could exchange information without fear of exploitation.