November 5th, 2003

breaking bad

Can you believe there's nothing out there in space?

How likely is it that there is life on other planets, circling other stars? I think it is difficult to deduce probability from a single data source (ie the Earth). We just don't know whether we are a billion to one lottery ticket, in a Universe that has bought billions of tickets, or merely the Ace of Hearts in a Universe that has shuffled countless decks of cards. Neither is inherently more likely given one event.

On the whole I would say that the likelihood of life existing beyond the earth is increased if we find that the Earth was seeded from Space with the vital precursors of life. It is increased still more if the earth was seeded with living things. If we found DNA on other planets in the solar system, for instance, I would consider 'life outside' to be more likely than not.

Therefore I am interested in the revelations here about the type of amino acids found in meteorites. Amino acids can be right or left 'handed'. Life on earth is composed of left handed amino acids. When generated in the famous experiments where organic compounds were flashed with electricity, amino acids were created in both right and left handed forms. But...

"Essentially all of your protein is made of L-amino acids," said Macko. "Why is that? We don't know. The curious thing is that if you go to a meteorite you find a predominance of the same thing."

This makes me think it was more likely that life on Earth came from space than was generated by random events on earth. It's not proof or anything, but it may be cause for optimism.