What Are The Odds

Some recent scientific research suggests life may have begun on comets and spread to Earth (and elsewhere).

One scientist said:

We now have a mechanism for how it could have happened. All the necessary elements - clay, organic molecules and water - are there. The longer time scale and the greater mass of comets make it overwhelmingly more likely that life began in space than on earth.

He may be right, but isn't this a bit presumptious? "Overwhelmingly more likely" if a bunch of other assumptions he can't be sure about are true, I'd say.

I'm reminded of the Drake Equation, which purports to figure how many civilizations are out in space that we can talk to. Trouble is, it involves a bunch of factors, some of which we understand, some of which we haven't a clue about, making the whole exercise fairly meaningless.

Yet, with all the uncertainty, we get this claim:

The researchers calculate the odds of life starting on Earth rather than inside a comet at one trillion trillion (10 to the power of 24) to one against.

There comes a point when you stop doing science and start doing public relations.