The same laws of physics apply everywhere. If we imagine those extraterrestrial beings sending us radio messages, we and they have something in common. We must. The very act of receiving the message means that we have radio technology in common. We have quantum mechanics. We have atomic physics. We have Newtonian gravitation. We can see that those laws of nature apply everywhere in the universe. It's not a question of what your biology is like. It's not a question of the sequence of events that led to you getting a technical civilization. The mere fact that you have a technical civilization means that you have come to grips to some extent with the universe as it really is. And so it is in that sense and in that sense alone, I believe, that it makes sense to talk about such an affinity between advanced beings and ourselves.
Five
I consider the idea of extraterrestrial intelligence a subject of philosophical, scientific, and even historical importance. If we were so lucky as to receive some sign of extraterrestrial intelligence, I think there is little doubt that it would be an extremely significant historical event. And if, on the other hand, we were to make a detailed and comprehensive search to no avail, that would also be something worth knowing It would say something about the rarity and preciousness of intelligent life and again, I believe, would have extremely important and beneficial social consequences. Therefore the search for extraterrestrial life is one of those few circumstances where both a success and a failure would be a success by all standards.
So I am hardly opposed to the idea of extraterrestrials visiting us. If we ourselves are poking around our solar system, if we are capable, as we are, of sending our own spacecraft not just to the other planets in our solar system but beyond our solar system to the stars, then surely other civilizations, if they exist, thousands or millions of years more advanced than ours, ought to be able to achieve interstellar spaceflight much more readily, much more swiftly.
And I don't for a moment deny this as a possibility. I would stress that the economy of effort is far greater for radio communication than direct communication by interstellar spacecraft. I would argue that you can broadcast to millions or thousands of millions of worlds simultaneously, speedily, inexpensively, in a way that even for a very advanced civilization would be much more difficult and costly to do via interstellar spacecraft. However, I certainly could not exclude the possibility that the Earth is now or once was visited. But precisely because the stakes in the answer are high, precisely because this is an issue that engages powerful emotions, we would in this case demand only the most scrupulous standards of evidence.
I want tonight to discuss two modern hypotheses that I think are proper to call folklore, the ancient astronaut hypothesis and the UFO or unidentified flying object hypothesis, and then attempt to connect them with the history of slightly more conventional religions.
The ancient astronaut hypothesis was popularized most effectively by a Swiss hotelier named Erich von Daniken. And his works, the first of which was called
The fundamental hypothesis of von Daniken was that there is impressed in the archaeology and folklore and myth of many civilizations on Earth certain indications of past contact with the Earth by extraterrestrial beings. This is not an absurd proposition on the face of it, but how acceptable the hypothesis is depends on how good the evidence is. And, unfortunately, the standards of evidence were extremely poor, in many cases nonexistent. So to give an example (and I promise I am not burlesquing the argument as I describe it), here is von Daniken's approach to the pyramids of Egypt: The pyramids of Egypt, he said, are constructed of individual blocks, rectangular paral- lelopipeds, each of which weighs twenty tons or thereabouts. 'Twenty tons,' he said. That's extremely heavy. Individual persons could not lift a twenty-ton block, much less many of them, to make a pyramid. Therefore modern construction equipment is necessary, and in 2000 to 3000 B.C., that could only be of extraterrestrial manufacture. Hence extraterrestrials exist.
Now, we can recognize that this argument neglects certain facts. If we knew nothing of Egyptian archaeology, we could nevertheless imagine ways in which large numbers of people could build massive edifices. (The Bible, after all, refers to ambitious construction projects, for example the enormous Tower of Babel.) And then when we look at the internal evidence, or even read Herodotus, who alluded to Egyptian pyramid-construction techniques, we find that there is an entirely self-consistent and perfectly natural explanation. In fact, there are many, some of which involve sending rafts up the Nile, and rollers to move the blocks, and the removal of underlying material. There were even inscriptions on a few key blocks that say the equivalent of 'My goodness, we did it!' signed 'Tiger Team Eleven,' which seems an unlikely delight in modest construction by some being who had effortlessly traveled through interstellar space. And we know that the first pyramid that was ever constructed fell down and that the second pyramid, halfway through construction, had the angle of the sides dramatically pared, because they had learned from the example of the first one that fell down. Again, an error of exceeding the angle of repose was unlikely to be made by an extraterrestrial spacefaring civilization.
Von Daniken noted that in Peru, in the plains of Nazca, there are large drawings on the desert that can properly be seen only from a great altitude. And they depict nothing very extraordinary in themselves: turkeys, condors, and other natural beasts and vegetables. But von Daniken wonders why anyone would construct something that could be seen only from a great altitude, from which he deduces not only that there were beings at a great altitude to see it but that such beings directed the construction, saying, 'A little to the left.' Now, in American football games, it is customary for people to be outfitted each with a square of cardboard on which is the fragment of a line or a letter. And at the appropriate moment, everybody holds up their piece, and from a great distance some symbol generally having to do with the hope for success of the home team is displayed. And yet no one deduces extraterrestrial intervention in such a case.
Or, von Daniken noted that in the Pacific, on Easter Island, there is a set of massive stone monoliths all facing to the sea, all of which are much too heavy to be lifted by one or two people and all of which, as Jacob Bronowski mentioned, look exactly like Benito Mussolini. They were quarried some substantial distance away on this very small island. And again von Daniken deduces extraterrestrial manufacture from the fact that he cannot himself figure out how people living before the industrial revolution could cut, transport, and erect these monoliths. And yet years before von Daniken wrote, Thor Heyerdahl had gone to Easter Island and with a small team using only the simplest of tools, had transported and erected one of these monoliths that had been found in a supine position. And the erection method included just shoving small bits of dirt and stone under one side of it until it got to the high, steeper angle and then finally stood up.
So there are many other such arguments by von Daniken, most of which have lower plausibility than the arguments I've just presented to you. I've presented some of his best cases. Fundamentally what von Daniken has done is to sell our ancestors short, to assume that people who lived a few thousand years ago or even a few hundred years ago were simply too stupid to figure anything out, certainly to work together for a long period of time to construct something of monumental dimensions. And yet people of a few hundred or a few thousand years ago were no less intelligent than we are, no less able. Perhaps in some ways they were better able to work together. The argument is absurdly specious. So how do we understand that so specious an argument could have been so wildly successful (although today one does not hear much about ancient astronauts)? It's an interesting question.
I think the answer is absolutely clear. The emotional appeal of von Daniken made perfect sense. It was the hope that extraterrestrials would come and save us from ourselves. The hope that if they had intervened many times in human history, surely in the present time, a time of great crisis recognized in the 1960s and '70s and manifestly clear today in an age of fifty-five thousand nuclear weapons, that the extraterrestrials would come and prevent us from doing the worst to ourselves. And in that sense I consider it an extremely dangerous doctrine,
