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c h a p t e r s e v e n Homo sapiens, Transhumanism, and the Postbiological Universe In the conventional human and robotic approaches to flight, the time assigned for the completion of space missions—relatively speaking—is short. The longest human expedition to the Moon (Apollo 15) took thirteen days. Individual astronauts may remain on the International Space Station for as much as six months. According to the most cautious plans, humans traveling to Mars would be gone twenty-nine months, hardly longer than sailors participating in the great terrestrial expeditions that traversed the Earth’s seas. The robotic spacecraft dispatched to Mars as part of the Viking program returned data for seven years. Only with the Voyager spacecraft, which took twelve years to investigate the four gas giants, did the length of time needed to complete an expedition exceed ten years. Compared to the average life spans of human beings—or to the overall length of their professional careers—these are not exceptional time spans.1 The effects of time on methods of space exploration are analogous in some ways to Einstein’s special theory of relativity. Einstein suggested that the passage of time was not fixed but varied according to the motion of the observer. Scientists have confirmed this phenomenon with atomic clocks launched into space. Traveling faster than their counterparts on Earth, the clocks keep slower time. Locally, the differences are tiny. Within the solar system, the effects of time relativity among bodies moving at different speeds are so slight as to be imperceptible without highly sensitive instruments. For investigations of the galaxy and universe, however, the effects become more pronounced.2 In a similar fashion, the incorporation of time relativity into visions of space travel seem unnecessary as long as explorers confine their activities to the solar system. Time effects became strikingly more important when exploration advocates began to think in galactic terms. Should any creatures respond to the electronic message aimed toward the globular star cluster M13 by astronomers Frank Drake and Carl Sagan in 1974, their response would not be heard for another fifty thousand years. The spacecraft Pioneer 10, which carried a plaque announcing the location of the civilization that sent it, would reach the vicinity of the red star Aldebaran in about two million years. Who knows what creatures might then occupy Earth? How might the consideration of the eons of time needed for space-exploring civilizations, including the human one, affect the effort? Will the human form evolve during this lengthy period, and how might it be altered because of its spacefaring experience? The results, to say the least, are strange. so where are they? Scientists and other people who contemplate space travel have noticed a curious feature in the Drake formula. About the time that Frank Drake began to listen for interstellar messages in 1960, he prepared an equation useful for estimating the number of extraterrestrial civilizations that might respond to a cosmic greeting card. The formula begins with the number of stars in the galaxy and gradually reduces that figure until it approximates the number of worlds harboring civilizations with technology capable of communicating with one another at any single point in time. The formula contains variables for the number of stars in the galaxy, the fraction with planets, the proportion of planets with conditions suitable for life, and the fraction on which life develops, becomes intelligent , develops technology, and decides to communicate across interstellar distances. The last element in the equation, called L, generated much attention. It represents the average life expectancy of a technological civilization whose members decide to communicate, expressed as a fraction of the span of life on a planet.3 In short, it represents time. Enrico Fermi, the great physicist, noticed a curious feature, the Fermi paradox . If the values describing L are small—say, a few hundred years over a half billion —then technological civilizations have a fairly short period of time within which to communicate from world to world. The effect of a small L on the overall formula is profound. The predicted number of civilizations capable of communicating with each other in the Milky Way galaxy at any one point in time 192 robots in space rapidly diminishes as the variable L shrinks in size. When the variable gets really small, it produces an outcome in the overall formula that approaches one. That is, the number of...


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