Dr. Seth Shostak, an astronomer, questions what if ET is out there at TEDxSanJoseCA. Here is the full transcript.
Listen to the MP3 Audio here: What if ET is out there by Seth Shostak at TEDxSanJoseCA
Is E.T. out there? Well, I work at the SETI Institute. That’s almost my name. SETI: Search for Extraterrestrial Intelligence. In other words, I look for aliens, and when I tell people that at a cocktail party, they usually look at me with a mildly incredulous look on their face. I try to keep my own face somewhat dispassionate.
Now, a lot of people think that this is kind of idealistic, ridiculous, maybe even hopeless, but I just want to talk to you a little bit about why I think that the job I have is actually a privilege, okay, and give you a little bit of the motivation for my getting into this line of work, if that’s what you call it. This thing — whoops, can we go back? Hello, come in, Earth. There we go. All right.
This is the Owens Valley Radio Observatory behind the Sierra Nevadas, and in 1968, I was working there collecting data for my thesis. Now, it’s kind of lonely, it’s kind of tedious, just collecting data, so I would amuse myself by taking photos at night of the telescopes or even of myself, because, at night, I would be the only hominid within about 30 miles. So here are pictures of myself.
The observatory had just acquired a new book, written by a Russian cosmologist by the name of Joseph Shklovsky, and then expanded and translated and edited by a little-known Cornell astronomer by the name of Carl Sagan.
And I remember reading that book, and at 3 in the morning I was reading this book and it was explaining how the antennas I was using to measure the spins of galaxies could also be used to communicate, to send bits of information from one star system to another. Now, at 3 o’clock in the morning when you’re all alone, haven’t had much sleep, that was a very romantic idea, but it was that idea — the fact that you could in fact prove that there’s somebody out there just using this same technology — that appealed to me so much that 20 years later I took a job at the SETI Institute.
Now, I have to say that my memory is notoriously porous, and I’ve often wondered whether there was any truth in this story, or I was just, misremembering something, but I recently just blew up this old negative of mine, and sure enough, there you can see the Shklovsky and Sagan book underneath that analog calculating device. So it was true.
All right. Now, the idea for doing this, it wasn’t very old at the time that I made that photo. The idea dates from 1960, when a young astronomer by the name of Frank Drake used this antenna in West Virginia, pointed it at a couple of nearby stars in the hopes of eavesdropping on E.T. Now, Frank didn’t hear anything. Actually he did, but it turned out to be the U.S. Air Force, which doesn’t count as extraterrestrial intelligence. But Drake’s idea here became very popular because it was very appealing — and I’ll get back to that — and on the basis of this experiment, which didn’t succeed, we have been doing SETI ever since, not continuously, but ever since.
We still haven’t heard anything. We still haven’t heard anything. In fact, we don’t know about any life beyond Earth, but I’m going to suggest to you that that’s going to change rather soon, and part of the reason, in fact, the majority of the reason why I think that’s going to change is that the equipment’s getting better. This is the Allen Telescope Array, about 350 miles from whatever seat you’re in right now. This is something that we’re using today to search for E.T., and the electronics have gotten very much better too. This is Frank Drake’s electronics in 1960. This is the Allen Telescope Array electronics today. Some pundit with too much time on his hands has reckoned that the new experiments are approximately 100 trillion times better than they were in 1960, 100 trillion times better. That’s a degree of an improvement that would look good on your report card, okay?
But something that’s not appreciated by the public is, in fact, that the experiment continues to get better, and, consequently, tends to get faster. This is a little plot, and every time you show a plot, you lose 10% of the audience. I have 12 of these. But what I plotted here is just some metric that shows how fast we’re searching. In other words, we’re looking for a needle in a haystack. We know how big the haystack is. It’s the galaxy. But we’re going through the haystack no longer with a teaspoon but with a skip loader, because of this increase in speed. In fact, those of you who are still conscious and mathematically competent, will note that this is a semi-log plot. In other words, the rate of increase is exponential. It’s exponentially improving.
Now, exponential is an overworked word. You hear it on the media all the time. They don’t really know what exponential means, but this is exponential. In fact, it’s doubling every 18 months, and, of course, every card-carrying member of the digerati knows that that’s Moore’s Law.
So this means that over the course of the next two dozen years, we’ll be able to look at a million star systems, a million star systems, looking for signals that would prove somebody’s out there. Well, a million star systems, is that interesting? I mean, how many of those star systems have planets? And the facts are, we didn’t know the answer to that even as recently as 15 years ago, and in fact, we really didn’t know it even as recently as six months ago. But now we do.
Recent results suggest that virtually every star has planets, and more than one. They’re like, kittens. You get a litter. You don’t get one kitten. You get a bunch. So in fact, this is a pretty accurate estimate of the number of planets in our galaxy, just in our galaxy, by the way, and I remind the non-astronomy majors among you that our galaxy is only one of 100 billion that we can see with our telescopes. That’s a lot of real estate, but of course, most of these planets are going to be kind of worthless, like, Mercury, or Neptune. Neptune’s probably not very big in your life.
So the question is, what fraction of these planets are actually suitable for life? We don’t know the answer to that either, but we will learn that answer this year, thanks to NASA’s Kepler Space Telescope, and in fact, the smart money, which is to say the people who work on this project, the smart money is suggesting that the fraction of planets that might be suitable for life is maybe one in a thousand, one in a hundred, something like that. Well, even taking the pessimistic estimate, that it’s one in a thousand, that means that there are at least a billion cousins of the Earth just in our own galaxy.
Okay, now I’ve given you a lot of numbers here, but they’re mostly big numbers, okay, so, you know, keep that in mind. There’s plenty of real estate, plenty of real estate in the universe, and if we’re the only bit of real estate in which there’s some interesting occupants, that makes you a miracle, and I know you like to think you’re a miracle, but if you do science, you learn rather quickly that every time you think you’re a miracle, you’re wrong, so probably not the case.
All right, so the bottom line is this: Because of the increase in speed, and because of the vast amount of habitable real estate in the cosmos, I figure we’re going to pick up a signal within two dozen years. And I feel strongly enough about that to make a bet with you: Either we’re going to find E.T. in the next two dozen years, or I’ll buy you a cup of coffee. So that’s not so bad. I mean, even with two dozen years, you open up your browser and there’s news of a signal, or you get a cup of coffee.