Running the numbers

To my mind, life isn't a miracle; it's an emergent feature of the universe. It's just one of the things that happens when you take a really hot mixture of hydrogen and a little helium, and leave it to cool for around 15 billion years. I therefore expect that life is to be found pretty much anywhere in the universe where physical conditions are conducive to its existence.

Given our current state of knowledge, that limits life to Earth-like planets. And , in our continuing search, we haven't yet found any. But as this BBC science report points out, we're getting close. And, what we're learning in the process suggests that such planets (or at least the types of solar system in which we're likely to find them), are probably more numerous than we thought. For more information on the latest developments, check out Exoplanet.org (nice graphics and tons of information).

A spin-off of all this activity is that the Drake equation is back in fashion. The equation (developed by Frank Drake for the first SETI conference back in 1961) is an attempt to calculate the number of detectable civilizations in our galaxy. There are a number of Drake equation calculators on the internet (there's one at the link above) - you can input values for the various parameters, push a button and get a result.

There's now also a Drake equation calculator on this BBC science page, along with a video of Drake talking about his equation (plus links to SETI and related areas). It's worth a look.