Sunday, July 18, 2004
Is there anybody out there?
One of my greatest dreams is that I will be alive when humans make contact with another race. This is what we call a 'really crappy dream', because I can't do a damn thing to make it happen, and the odds of it happening are infinitesimal. I can't say for sure when it started, but when we first set up the Arecibo telescope to transmit a sequence of prime numbers, it was clear that the idea of sentient non-human life was finally becoming mainstream.
I say it plainly that I believe it would be the greatest event in human history to find evidence of other life in the universe. But our technology is so limited and our knowledge of physics so small that it is almost inconceivable for us to find other civilizations. All we can hope is that the other civilizations contact us. This is where SETI comes into play. SETI is the Search for Extraterrestrial Intelligence, and it is being conducted all around the world by computers just like yours and mine. The way SETI works is that signals collected from radio telescopes are crunched by computers piece by piece, in order to see if they represent more than just noise. But because this number crunching is so intense, we are unable to do it in real-time and are forced to look at data that has been collected but not processed.
The problem with this approach is not only is it inefficient and time-consuming, but the SETI telescopes represent a ridiculously small proportion of the sky. All odds are against SETI to actually find a signal.
The barriers to communication between two distant worlds is immense. First, the two worlds have to both evolve sentient life. Secondly, the two worlds must develop life that is capable of technology of transmission and reception. Thirdly, both civilization's timeframes have to overlap each other, and both civilizations have to be watching and/or transmitting to the other's
coordinates.
We don't know what the probabilities of evolving sentient life, other than our own Earth. Out of all the planets we have seen, only one has developed life. And on that one world, there have been trillions of species on the planet, and only a very few are sentient. Only one is technological. And when you take note of the age of the universe (4 billion years, give or take a few billion), and the age of our ability to send and receive information (80 years, give or take a few), AND the fact that light travels very slowly compared to the size of the universe (4 years to our nearest neighboring star), and the window of opportunity seems inconceivably small.
It very well may be true that alien civilizations abound in the universe. But if they are located 80,000 light years away, to us they may as well not exist. Can we possibly hope to discover other life forms? Or would we venture out into space only to find ourselves very, very alone?
Obviously this calculation of odds takes into account only our current technology and our current knowledge of physics. 300 years ago, sending a message across the globe in a split second to a specific person may very well be today's equivalent of sending a message across the galaxy. Perhaps learning more about physics will give us a better understanding of how to bend the rules and get ever closer to the alien races that our science fiction writers so desperately hope are out there.
This is why I consider myself a technologist. Sometimes it is necessary to pursue technology for its own sake. At our core, I believe that humans are explorers, and whether it was the wheel, reinforced wooden ships, the Model T, or the Saturn V rocket, I think technology has always helped satisfy our wanderlust. While technology sometimes brings out the worst in us (it is not too unlikely the atomic bomb will end our planet before we can get off it), I believe it is the only way for us to push forward. Learning more about our universe is always a noble pursuit, and harnessing that knowledge to create and invent is almost all that keeps my faith in humanity alive.
But as for my crappy dream, even technology can't save it. All I can hope for is that an alien race with superior technology visits our planet, reads this post, and decides to pity me and present themselves to the human race. Of course, we also have to hope they don't totally wipe us out, like every advanced human society has done to less technologically advanced societies.... but that's a totally different story. And yet, I almost think it would be worth it. Almost.
I say it plainly that I believe it would be the greatest event in human history to find evidence of other life in the universe. But our technology is so limited and our knowledge of physics so small that it is almost inconceivable for us to find other civilizations. All we can hope is that the other civilizations contact us. This is where SETI comes into play. SETI is the Search for Extraterrestrial Intelligence, and it is being conducted all around the world by computers just like yours and mine. The way SETI works is that signals collected from radio telescopes are crunched by computers piece by piece, in order to see if they represent more than just noise. But because this number crunching is so intense, we are unable to do it in real-time and are forced to look at data that has been collected but not processed.
The problem with this approach is not only is it inefficient and time-consuming, but the SETI telescopes represent a ridiculously small proportion of the sky. All odds are against SETI to actually find a signal.
The barriers to communication between two distant worlds is immense. First, the two worlds have to both evolve sentient life. Secondly, the two worlds must develop life that is capable of technology of transmission and reception. Thirdly, both civilization's timeframes have to overlap each other, and both civilizations have to be watching and/or transmitting to the other's
coordinates.
We don't know what the probabilities of evolving sentient life, other than our own Earth. Out of all the planets we have seen, only one has developed life. And on that one world, there have been trillions of species on the planet, and only a very few are sentient. Only one is technological. And when you take note of the age of the universe (4 billion years, give or take a few billion), and the age of our ability to send and receive information (80 years, give or take a few), AND the fact that light travels very slowly compared to the size of the universe (4 years to our nearest neighboring star), and the window of opportunity seems inconceivably small.
It very well may be true that alien civilizations abound in the universe. But if they are located 80,000 light years away, to us they may as well not exist. Can we possibly hope to discover other life forms? Or would we venture out into space only to find ourselves very, very alone?
Obviously this calculation of odds takes into account only our current technology and our current knowledge of physics. 300 years ago, sending a message across the globe in a split second to a specific person may very well be today's equivalent of sending a message across the galaxy. Perhaps learning more about physics will give us a better understanding of how to bend the rules and get ever closer to the alien races that our science fiction writers so desperately hope are out there.
This is why I consider myself a technologist. Sometimes it is necessary to pursue technology for its own sake. At our core, I believe that humans are explorers, and whether it was the wheel, reinforced wooden ships, the Model T, or the Saturn V rocket, I think technology has always helped satisfy our wanderlust. While technology sometimes brings out the worst in us (it is not too unlikely the atomic bomb will end our planet before we can get off it), I believe it is the only way for us to push forward. Learning more about our universe is always a noble pursuit, and harnessing that knowledge to create and invent is almost all that keeps my faith in humanity alive.
But as for my crappy dream, even technology can't save it. All I can hope for is that an alien race with superior technology visits our planet, reads this post, and decides to pity me and present themselves to the human race. Of course, we also have to hope they don't totally wipe us out, like every advanced human society has done to less technologically advanced societies.... but that's a totally different story. And yet, I almost think it would be worth it. Almost.
# posted by Stuart @ 1:33 AM 
