By Rae Avery
The universe is incredibly lonely, but also teeming with life. Probably. Maybe. We think it’s a distinct possibility, at least.
When I was six years old, Sesame Street’s Ernie sang this little ode: “Oh, who are the people in your neighborhood - the people that you meet each day?” This is a fair question to ask when your “neighborhood” consists of a couple corner shops, an auto dealership and some apartment buildings, but when it comes to our galactic neighborhood, who are the people we are supposed to be meeting? This is the question that Fermi’s Paradox seeks to answer.
To put the vastness of our universe in perspective, one useful comparison would be to imagine all the stars in the universe as sand, and for every single grain of sand on earth, there are 10,000 stars. Not only that, but for each grain of sand, there are also expected to be 100 earth-like planets that could potentially sustain life. Following this logic, the next logical step would be to assume that with the sheer number of “earths,” something or someone must live on at least one, if not millions.
The Drake equation puts Fermi’s Paradox into the actual mathematical expression you may have heard on old episodes of Carl Sagan’s Cosmos. It goes something like this: start with the rate of star formation in our galaxy. Multiply this by the stars that have planets. Multiply that by the average number of planets that could possibly sustain life (per star with planets). Still with me? Multiply that by the planets that actually do sustain life. Multiply that by the number of planets that sustain intelligent life. Multiply that by the number of planets that contain intelligent life that are able and willing to communicate. And, finally, multiply that by the life expectancy of such a civilization. The result is the number of civilizations we might reasonably expect to communicate with at any given time.
SETI, or Search for Extraterrestrial Intelligence, is a non-profit research organization and has been searching for signs of alien life in outer space by scanning for electromagnetic radiation and other potential signs of life with an impressive array of ground-based telescopes, literally checking day and night without stopping since 1984. But since their inception, they inexplicably still have yet to encounter even one such message from any entity anywhere.
The basis of Fermi’s Paradox is this: that the universe is so old (comparatively to our earth), and the basic building blocks of life so abundant, that our cosmic community should be bursting with some kind of life, other than our own …shouldn’t it? For some reason it isn’t. At least not that we can observe. The cold unfortunate math of the Drake Equation leads us to the sad realization that even if life is all over the universe, the odds of an overlap between a civilization reaching the ability to communicate, being willing to communicate, and being within a few light years of another such civilization are astoundingly low. Even if E.T. is out there we ought never to expect E.T. to phone us, let alone visit and need to phone home. The good people at SETI will make sure the line is clear, though, just in case.