Perhaps weirdly this blog is inspired by watching an insect on my bathroom floor. It was so small you needed a lens to see any detail at all. But there it is, perfect in its own way, complete with legs a sensory system and enough of a brain and nervous system that allows it to live, move, feed and of course most importantly reproduce. How does it work at that scale is the question I ask and also how much smaller (I know there are bacteria and viruses, although there is some debate as whether viruses count as life?) can such a complex creature get? And the fact that it does exist makes me think that ‘life’, given half a chance, must be a common natural state.
There has been quite a lot in the press recently about the discovery of planets in the optimum position around stars for life to exist. Or perhaps rather for liquid water to exist and therefore the chance of life to evolve in much the same way as it did on our own planet However, if you think of life on earth, it exists in some form or other in whatever environments the planet can throw at it. So I ask does life have to be limited to those type of worlds? Why can’t it be, to use the old Star Trek quote, ‘life, Jim, but not as we know it.’? Surely life consists of a definitive organism, that generates energy, thereby enabling it to maintain itself and then can reproduce itself in one way or another. Or is even that too tight a definition?
Life on earth is defined by water and perhaps in its development by the particular property of water that when it freezes the molecules push each other further apart, hence it floats. So that in a large body of water the surface may freeze, but underneath there is always liquid water at a constant temperature. Maybe what life needs to take hold is a consistency of environment (with manageable variation)? So why can’t liquid methane or layers within a gas giant provide that same consistent environment, just to give two examples?
As writers and readers of science fiction maybe we’re guilty of being lazy, of limiting our view of life to the familiar. The one notable exception I know of is Ian M Banks who in one of his books has a large intelligent life form in a gas giant. Perhaps we need to stretch our imaginations a little and then future scientists looking for life elsewhere might be inspired to think and look more widely. Who knows what wonders we might find?
I suppose the note to self here is to try harder with my own aliens.
As always comments and ideas are always welcome.