The Search for Extra-Terrestial Intelligence (SETI) project has been going on for 54 years now. No intelligent life - or life at all - has been found off earth, but the universe is vast and the project is young.
|Is anyone out there? Well, the odds are against it |
unless divine agency is postulated.
Now SETI's Seth Shostak says,
"I think we'll find E.T. within two dozen years using these sorts of experiments," Shostak said here Thursday (Feb. 6) during a talk at the 2014 NASA Innovative Advanced Concepts (NIAC) symposium at Stanford University. [13 Ways to Hunt Intelligent Alien Life]
"Instead of looking at a few thousand star systems, which is the tally so far, we will have looked at maybe a million star systems" 24 years from now, Shostak said. "A million might be the right number to find something."
Shostak's optimism is based partly on observations by NASA's planet-hunting Kepler space telescope, which has shown that the Milky Way galaxy likely teems with worlds capable of supporting life as we know it.
"The bottom line is, like one in five stars has at least one planet where life might spring up," Shostak said. "That's a fantastically large percentage. That means in our galaxy, there's on the order of tens of billions of Earth-like worlds."
I am sure, though, that this bold prediction is wholly unrelated to the fact that the article later says that, "getting enough funding to keep scanning the skies is a constant problem."
So let's just say we are right on the edge of success and with millions more dollars we'll succeed! But of course, that's just coincidental.
The faith that life necessarily exists off earth is called the "theory of mediocrity" because it holds that conditions on earth are simply average and that life-producing conditions are therefore abundant in the universe. But even SETI advocates admit that there is an indescribably-huge leap from the formation of life to the rise of life that is at least human-level intelligent.
The first evidence of microbial life on Earth, for instance, dates from 3.8 billion years ago — just 700 million years after our planet formed. But it took another 1.7 billion years for multicellular life to evolve. Humans didn't emerge until 200,000 years ago, and we've become a truly technological species in just the last century or so.
Science writer Mark Thompson explains that even a 14-billion-year-old universe may not be old enough to result in planets teeming with life, especially intelligent life.
It seems that the evolution of stars precluded the formation of rocky planets much before the appearance of Population I stars. If that is the case, and adding a generous margin for error, it looks like the first planets like Earth would have formed no earlier than 8 billion years ago.
If that is true, then it may well be that we are not necessarily the first life, but perhaps amongst the first intelligent life (as we know it) to evolve.
Furthermore, there is no teleology, or inevitability, in evolution theory. No outcome is inevitable, there are no such things as "higher" life forms. There is only survival, or not. Hence, technological, inventive beings are not bound to form at all.. There is no "progress" in the development of life in the first place and no evolutionary outcome is inevitable in any way.
That's why Harvard biologist Ernst Mayr pointed out that since life first appeared on Earth, there have been an estimated 50 billion species. And yet only one, us, has developed high intelligence. Mayr says that such intelligence does not obviously offer a species survival advantage (consider the cockroach) and hence may be so rare that homo sapiens-level intelligence may be a "one off" in the universe.
The ponderous word overlaying all this is "if." If life exists at all in earth or elsewhere simply because of the chance compounding of chemicals in bio-capable worlds, then it is very difficult to confidently conclude that human beings are remotely likely to encounter any kind of life off earth.
Why? Because the odds are so supremely unlikely that life formed here on earth by chance that for life to also have formed elsewhere would be like winning a million-dollar lottery a million times in a row, according to Astronomy magazine editor Robert Naeye.
I posted a summary of just some of the odds in, "The Massive Improbability of Life
." That is one reason that Robert Griffiths, who won the Heinemann prize in mathematical physics, stated,
"If we need an atheist for a debate, I go to the philosophy department. The physics department isn't much use."But suppose there are between 200-500 billion intelligent species in the universe. Does that sound like a lot? It's only one per galaxy.
In 2011 I put together a slide show on this topic. It is below and just below it is a video from the SciAm site that is a good overall summary of the current scientific state of thinking.