Friday, December 08, 2006

Is There Life in Outer Space? (Part 2)

I mentioned in my last comment to Dedwarmo
Is There Life in Outer Space? (Part 1) that if he found the words, "Steven Loves Priscilla" scrawled in the sand at the beach, he wouldn't scratch his head and wonder if it was brought about by the receding tide. Likewise, one would not wonder if wind and rain created the heads on Mount Rushmore, even if he had never heard the name Gutzon Borglum or seen another carver's work.

What do the letters on the beach and the heads on Mount Rushmore have in common? The answer is information.

That is what SETI scientists are looking for. And information has two components: specificity and complexity.


Something is specified if the arrangement has meaning. The word "the" is specified, but not very complex. If you randomly pulled letters out of a hat and got the word "the," you wouldn't assume the game was rigged, nor if scientists received the word "the" from space would they assume it was caused by intelligence.


Random noise is quite complex, but it doesn't mean anything. One way of defining complexity is that which has a low probability of occurring randomly. For instance, the following 30 letters have an extremely low probability of occurring in any random arrangement of 30 letters: ldjhoirojhksdghhlnjdlbhkcjmnjf. They are complex, but not specified, since they have no meaning.

Now if scientists heard, "Four score and seven years ago, our fathers brought forth, upon this continent, a new nation..." they would immediately assume the source was intelligent because the data is both specified and complex. That's information and information always comes from intelligence.


  1. Detecting E.T. intelligence has another level of difficulty. We won't receive a sequence of letters. At best we'll receive a modulated radio signal. And we won't know if it was intended to be decoded as audio, video, text or some other form of information.

    How do biological systems fit your definition of intelligence?

  2. I don't think you have to be an atheist to believe in the SETI cause, but I'm sure many are. Atheists and evolurionists must believe that intelligence can come from randomness. So even describing a thing or organism as having characteristics of intelligence or containing information does not necessarily hurt their argument. Intelligent Design proponents seem to say that it is self-evident that living things were intentionally designed by a Designer, just as self-evident as a pocket watch. I don't think it is so obvious.

  3. Here's a response to your first comment:

    I agree that it is possible that we could receive data from an intelligent source and falsely assume that it is random. Most people would assume the following combination of letters to be random as well:

    Yawezekana ya kuwa hunijui lakini najua kila kitu juu yako Najua kukaa kwako na Zaburi.

    But those just happen to be Bible verses in Swahili. If you didn't know the language, they would appear to be random letters.

    However, if you found this sequence, "Four score and seven years ago..." you would know beyond any doubt that it was produced by an intelligence, because you know it contains information.

    So, any time there is information, there is intelligence, whether or not we know it at the time.

    Biological systems show evidence of intelligence because of the information they contain.

  4. Not all information is the same. A pocket watch has a very different kind of intelligence behind it than DNA, if there is any intelligence behind DNA. How do we know that all "information" comes from intelligence?