"Life exists on other planets and we will find it within 20 years," said Andrei Finkelstein, director of the Russian Academy of Sciences Applied Astronomy Institute. Finkelstein made this prediction at a conference this week in St. Petersburg, and it instantly made headlines around the world. After all, while others have argued the same point, that we will soon detect intelligent life, and perhaps civilization on another planet, Finkelstein's time scale is particularly bold. For instance, theoretical physicist and Big Think expert Dr. Michio Kaku says contact with our earth-like twins could occur "perhaps sometime in this century." SETI (Search for Extraterrestrial Intelligence) Institute Director Jill Carter hedged her bet when she told Big Think the detection of an extraterrestrial signal "could happen tomorrow," and it could also "happen never."
What's the Significance?
How likely is it that life will be discovered on an Earth-like planet? This question was once the stuff of supermarket tabloids. Today, "the pendulum has swung from extreme skepticism about extraterrestrial life to extreme credulity," says Arizona State University Cosmologist and Astrobiologist Paul Davies. And "the truth is somewhere in between," Davies says.
While credulity may be in fashion, the actual scientific "facts on the ground," however, have not changed much over the last 50 years. And many people are asking why there is no evidence. With all of the celestial monitoring that has gone on with increasingly powerful instruments over the years, what accounts for the "eerie silence"?
According to Professor Davies:
If you ask the astronomers of the sharp end of SETI [Search for Extraterrestrial Intelligence] why they think there has been an eerie silence they’ll say, “Well we only have been doing it for 50 years. We’ve just started. What more do you expect? It’s a big universe out there.” And in fact, to put that into context they look carefully. It’s just a few thousand stars. There are 400 billion stars within our Milky Way galaxy alone, so it is a needle in a haystack search.
A needle in a haystack indeed. And yet, there is a way to calculate the possibility that a life-sustaining planet exists in our galaxy. In this video below, Carl Sagan describes the so-called "Drake Equation," named after SETI founder Frank Drake, in the Cosmos program called "The Encyclopaedia Galactica." The Drake Equation is used to calculate the number of planets in the Milky Way Galaxy that are suitable for life. The answer, it turns out, is in the millions for our galaxy alone.
Contrasted with this is a pessimistic notion known as the Fermi paradox that posits that after several billion years of evolution, an intelligent civilization would likely destroy itself, very shortly after achieving advanced technological abilities such as radio astronomy. On the other hand, Sagan demonstrates the possibilities at play if we were to take a generally more optimistic view of what can be achieved by intelligent life.