When we stare at the stars, what do we see? Our eyes only see the billions upon billions of tiny lights, indicative of the simultaneously destructive and life-giving force of nuclear fusion occurring millions of light years away.
But our logical minds, in concert with our imaginations, tell us that there must be something more.
I am not talking about some ethereal presence, but something real and possibly tangible – civilizations of intelligent organisms, complete with culture, math, science and perhaps even religion not too dissimilar to our own. In other words, aliens … extraterrestrials. Although extraterrestrials have yet to make contact with us (that we know of), statistics and basic evolutionary principles dictate that we are not, and cannot, be alone.
Carl Sagan, one of the greatest men to ever write about the cosmos, once said, “It is in our nature to fear the unknown … but could it be that out of the hundred billion stars in the Milky Way galaxy, our hum-drum sun is the only one that supports life?”
Obviously, I am a romantic futurist, convinced beyond a doubt that not only are we not alone, but that we will one day meet our galactic housemates.
Back in 1960, Professor Frank Drake at UC Santa Cruz devised a mathematical model to predict how many intelligent species we share our galaxy with. I recommend looking up the Drake Equation on Wikipedia; it makes for quite an interesting read, even to the not-scientifically inclined people out there.
Drake estimated that we share the galaxy with about 10 other intelligent species, and that’s just in the Milky Way Galaxy. There are 10^11 galaxies visible from earth, which we can extrapolate to mean that there are about 10^12 intelligent species in the universe – that is 10 with 12 zeros after it, a very big number.
To get an idea of what that looks like, Google search an image of the Hubble Deep Field. That image contains 3,000 galaxies, and it only covers 2.5 arc minutes, or 1/500,000th of the entire sky. Even if Drake’s equation was grossly optimistic, more conservative estimates still put the number of intelligent species close to a hundred million.
You may be thinking that the formation of life is an extremely unlikely event, and therefore could not happen twice. It is true that for life as we know it to have formed, a series of extraordinarily rare events must have taken place. But when we consider the immense number of opportunities available around the universe, those odds start to look a little better.
There are so many criteria that must be met for life to form: the planet must sit in its star’s habitable zone, the planet must have tectonic activity to recycle resources and the atmosphere must have enough free-floating amino acids for the first replicators to form. I highly recommend Richard Dawkins’s book The Selfish Gene, which covers the origins and development of these replicators.
I am convinced we are not alone, but even after reasoning that there are others out there, it is another game entirely to calculate the odds of actually contacting another civilization.
The odds are not in our favor. If a species has the ability to contact us, or even physically reach our planet, then we are already far outclassed both technologically and intellectually. But the real limitation comes with the vast distances involved.
Even if we are existing at the same time as another civilization, the millions of light years separating us would mean that their electronic signals would not reach us, and ours would not reach them until millions of years after we are both extinct. The only signals that we are likely to receive are those of a race long-since gone.
That is, unless we invent faster-than-light travel …
HUDSON LOFCHIE is an alien enthusiast. He enjoys reading about the possibility of life beyond our own. Contact him at science@theaggie.org.
