Cosmos - Carl Sagan [61]
Might it really be possible—in fact and not in fancy—to venture with John Carter to the Kingdom of Helium on the planet Mars? Could we venture out on a summer evening, our way illuminated by the two hurtling moons of Barsoom, for a journey of high scientific adventure? Even if all Lowell’s conclusions about Mars, including the existence of the fabled canals, turned out to be bankrupt, his depiction of the planet had at least this virtue: it aroused generations of eight-year-olds, myself among them, to consider the exploration of the planets as a real possibility, to wonder if we ourselves might one day voyage to Mars. John Carter got there by standing in an open field, spreading his hands and wishing. I can remember spending many an hour in my boyhood, arms resolutely outstretched in an empty field, imploring what I believed to be Mars to transport me there. It never worked. There had to be some other way.
Like organisms, machines also have their evolutions. The rocket began, like the gunpowder that first powered it, in China where it was used for ceremonial and aesthetic purposes. Imported to Europe around the fourteenth century, it was applied to warfare, discussed in the late nineteenth century as a means of transportation to the planets by the Russian schoolteacher Konstantin Tsiolkovsky, and first developed seriously for high altitude flight by the American scientist Robert Goddard. The German V-2 military rocket of World War II employed virtually all of Goddard’s innovations and culminated in 1948 in the two-stage launching of the V-2/WAC Corporal combination to the then-unprecedented altitude of 400 kilometers. In the 1950’s, engineering advances organized by Sergei Korolov in the Soviet Union and Wernher von Braun in the United States, funded as delivery systems for weapons of mass destruction, led to the first artificial satellites. The pace of progress has continued to be brisk: manned orbital flight; humans orbiting, then landing on the moon; and unmanned spacecraft outward bound throughout the solar system. Many other nations have now launched spacecraft, including Britain, France, Canada, Japan and China, the society that invented the rocket in the first place.
Among the early applications of the space rocket, as Tsiolkovsky and Goddard (who as a young man had read Wells and had been stimulated by the lectures of Percival Lowell) delighted in imagining, were an orbiting scientific station to monitor the Earth from a great height and a probe to search for life on Mars. Both these dreams have now been fulfilled.
Imagine yourself a visitor from some other and quite alien planet, approaching Earth with no preconceptions. Your view of the planet improves as you come closer and more and more fine detail stands out. Is the planet inhabited? At what point can you decide? If there are intelligent beings, perhaps they have created engineering structures that have high-contrast components on a scale of a few kilometers, structures detectable when our optical systems and distance from the Earth provide kilometer resolution. Yet at this level of detail, the Earth seems utterly barren. There is no sign of life, intelligent or otherwise, in places we call Washington, New York, Boston, Moscow, London, Paris, Berlin, Tokyo and Peking. If there are intelligent beings on Earth, they have not much modified the landscape into regular geometrical patterns at kilometer resolution.
But when we improve the resolution tenfold, when we begin to see detail as small as a hundred meters across, the situation changes. Many places on Earth seem suddenly to crystallize out, revealing an intricate pattern of squares and rectangles, straight lines and circles. These are, in fact, the engineering artifacts of intelligent beings: roads, highways, canals, farmland, city streets—a pattern disclosing the twin human passions for Euclidean geometry and territoriality. On this scale, intelligent life can