All in all I like Michael Crichton. Probably every person of my age in the post-soviet area has read "The Andromeda Strain" (well, there was not a lot of sciende fiction in USSR - although there were some extremely good authors... but I digress :).
Anyway, back to the subject - Caltech lecture by M.Crichton called 'Aliens Cause Global Warming'. Interesting lecture where M.Crichton analyses Drake equation, nuclear winter and global warming and how those ideas fit into the narrative of the science. And although I for the most part agree with the lecture I think that at least one of the points made by M.Crichton is plainly wrong!
I'm talking about the Drake equation. I'm not an expert of SETI and do not purport to be one, but I think M.Crichton is wrong by declaring that it has "nothing to do with science". Lets have a look:
In 1960, Drake organizes the first SETI conference, and came up with the now-famous Drake equation:Yep, it is. So far so good :)
N=N* fp ne fl fi fc fL
[where N is the number of stars in the Milky Way galaxy; fp is the fraction with planets; ne is the number of planets per star capable of supporting life; fl is the fraction of planets where life evolves; fi is the fraction where intelligent life evolves; and fc is the fraction that communicates; and fL is the fraction of the planet's life during which the communicating civilizations live.]
This serious-looking equation gave SETI a serious footing as a legitimate intellectual inquiry. The problem, of course, is that none of the terms can be known, and most cannot even be estimated. The only way to work the equation is to fill in with guesses. And guesses-just so we're clear-are merely expressions of prejudice. Nor can there be "informed guesses." If you need to state how many planets with life choose to communicate, there is simply no way to make an informed guess. It's simply prejudice.And here already M.Crichton makes a mistake (or should I say "expresses his prejudices" ;).
There is a difference between "can't be known", "can't be estimated" and "can't be known now", "can't be estimated now".
The fact that science is unable to answer some questions NOW!, does not mean, that it will not be able to answer those questions in the future.
As a result, the Drake equation can have any value from "billions and billions" to zero. An expression that can mean anything means nothing.Yes and no. We can not estimate the result with any measure of certainty, but for one, we can at least suppose, that the number is higher than zero (the history of science teaches us that - humanity likes to think of itself as exceptional, but science again and again shows us that it is not so).
Upper limit can also be estimated - although, sure, with a lot of uncertainty.
Speaking precisely, the Drake equation is literally meaningless, and has nothing to do with science. I take the hard view that science involves the creation of testable hypotheses. The Drake equation cannot be tested and therefore SETI is not science. SETI is unquestionably a religion. Faith is defined as the firm belief in something for which there is no proof. The belief that the Koran is the word of God is a matter of faith. The belief that God created the universe in seven days is a matter of faith. The belief that there are other life forms in the universe is a matter of faith. There is not a single shred of evidence for any other life forms, and in forty years of searching, none has been discovered. There is absolutely no evidentiary reason to maintain this belief. SETI is a religion.Wrong!
Yes, the science is all about testable hypotheses, but that does not mean, that it should be possible to test all of the scientific hypotheses right now - today or tomorrow. Maybe in some cases we just need some more scientific progress before we can test this particular hypothesis.
There is a difference between hypotheses which are untestable, like the god hypothesis, and those which are untested - temporarily "untestable" if you want, like early atomic theories, because the science / scientists at the moment lack the necessary ability / knowledge / skills.
What is funny, is that M.Crichton is calling SETI a religion, but in fact he is using the same argument which is used by a lot of religious fanatics - "if you can't explain something it means god exists". Yes, the good old god of the gaps.
M.Crichtons adaptation of this "argument" sounds more or less the same "if you can't explain something now, if you can't test the hypothesis this very moment - it's not science".
But the history of the science shows, that in fact it is quite the opposite - this exactly is what the science is all about: science formulates a lot of hypotheses which are way ahead of their time and can not be tested at the moment when they are formulated. And in 1903 Wright Flyer tested some of the hypotheses which when formulated a few hundred years ago were "meaningless" and "untestable".
Science is science... even if today it does not know all the answers to all the questions in universe...