Broca's Brain - Carl Sagan [121]
Our planet turns. When it is midday at one spot on the Earth, it is the dead of night on the other side. The Earth has therefore been conveniently arranged into twenty-four time zones of more or less equal width, making strips of longitude around the planet. If we fly very fast, we create situations our minds can accommodate but our bodies can abide only with great difficulty. It is a commonplace today to fly in relatively short trips westward and arrive before we leave—for example, when we take less than an hour to fly between two points separated by one time zone. When I take a 9 P.M. flight to London, it is already tomorrow at my destination. When I arrive, after a five- or six-hour flight, it is late at night for me but the beginning of the business day at my destination. My body senses something wrong, my circadian rhythms go awry, and it takes a few days to get adjusted to English time. A flight from New York to New Delhi is, in this respect, even more vexing.
I find it very interesting that two of the most gifted and inventive science-fiction writers of the twentieth century—Isaac Asimov and Ray Bradbury—both refuse to fly. Their minds have come to grips with interplanetary and interstellar spaceflight, but their bodies rebel at a DC-3. The rate of change in transportation technology has simply been too great for many of us to accommodate conveniently.
Much stranger possibilities are now practical. The Earth turns on its axis once every twenty-four hours. The circumference of the Earth is 25,000 miles. Thus, if we were able to travel at 25,000/24 = 1,040 miles per hour, we could just compensate for the Earth’s rotation, and traveling westward at sunset, could maintain ourselves at sunset for the entire journey even if we circumnavigated the planet. (In fact, such a journey would also maintain us at the same local time as we journey westward from time zone to time zone, until we cross the international dateline and plunge precipitously into tomorrow.) But 1,040 miles per hour is less than twice the speed of sound and there are, worldwide, dozens of kinds of aircraft, chiefly military, that are capable of such speeds.*
Some commercial aircraft, such as the Anglo-French Concorde, have comparable capabilities. The question, I think, is not: Can we go faster? but Do we have to? There has been concern expressed, some of it in my view quite appropriately, about whether the conveniences supersonic transports provide can possibly compensate for their overall cost and their ecological impact.
Most of the demand for high-speed long-distance travel comes from businessmen and government officials who need to have conferences with their opposite numbers in other states or countries. But what is really involved here is not the transportation of material but the transportation of information. I think much of the necessity for high-speed transport could be avoided if the existing communications technology were better used. I have many times participated in government or private meetings in which there were, say, twenty participants, each of whom was paid $500 for transportation and living expenses merely to attend the meeting—the cost of which was therefore $10,000 just to get the participants together. But all the participants ever exchange is information. Video phones, leased telephone lines, and facsimile reproducers to transmit paper copies of notes and diagrams would, I believe, serve as well or even better. There is no significant function of such a meeting—including private discussions among the participants “in the corridor”—that cannot