In the old days when we used to talk about the possibility of life beyond Earth we would invariably get into a debate about the likelihood of a silicon-based variety. I think it was Carl Sagan in an “I refute it thus!”-moment who said that if a silicon giraffe had walked by the Viking Lander (on Mars) they would have got a picture of it. The bottom-line is that silicon-based life is so unlikely – why would the laws of nature have conspired to use silicon when there’s carbon? Besides in a sense, humans are silicon-based since they are composed of 0.025% Si (present, I think, in things like fingernails etc.). Also, as a society and species we are now absolutely reliant on silicon for our survival, beyond merely providing the platform on which we stand. I’m referring of course to silicon chips. I was going to write “non-biological silicon chips”, but that got me thinking, no, they are biologically produced. Part of our habitat is cyberspace – it is hard to imagine “life” now without it.
Anyway, we digress; there are lots of really creative ideas (both science-possible and science-fiction) for what forms alien life might take. It is even possible that life exists in the Sun (just think of the magnitude of the energy available). But the interesting thing is this: cosmologists tell us that 95%, or so, of all the mass-energy in the Universe is not normal (haha, what vanity to call the 5% that we’re in “normal”). Rather, it is dark (dark matter, dark energy) and we can’t see it. We just know (on the basis of scientific interpretation) it has to be there. As an aside here I note that cosmologists are sometimes referred to as being “often wrong but never in doubt”.
In other words, it seems to me, from a purely statistical perspective there has got to be a greater chance of life being in the dark bit than in the abnormal bit that we inhabit. So, if we know life is here (looks in the mirror to check) then it is almost certain to be elsewhere (but where we can’t see it). And if we can’t see it, or we don’t otherwise know how to recognise it, then perhaps it could be a whole lot closer to home than we think.
What a great post, Ian. Years ago I ran a series of review articles in Nature on the theme of astrobiology (ha! another modish term of yesteryear!) one of which was by Jack Cohen and Ian Stewart who were very critical of the ‘follow-the-water’ strategy then in fashion. (Incidentally, Cohen and Stewart wrote a novel called Wheelers that did indeed posit plasma-based beings in and around the Sun, and I am sure that the concept didn’t begin and end with these two authors). I think that any search for life should be based on the search for systems that are far from equilibrium. When I was thinking about this, while trying to write a proposal for a book on the subject, I wondered whether there might be life that could be defined as such, but that we might not be able to recognize. However, a friend soon put me right. Were he to observe, he said, two enormous clumps of einsteinium hanging ins pace, he’d know that something was up. Not life as we know it, Jim, but definitely something far from equilibrium. But Dark Matter, eh? How would we recognize a system that’s far from equilibrium in a class of matter we can’t even detect?
Ian, nice piece!
It strikes me, all of a brandy infuzed sudden1, how limited scientific interpretation is by the mathematical system we rely upon. My mathematics is limited, but somewhere, bells are ringing.
Henry: As well as my maths, my Latin ain’t what it orta be. Is ins pace something like mons meg, or en pedantrae?
1 More on this soon, if the fuze clears
No, just am isprint.
Whilst we’re on he subject of einsteinium Well, it is red nose day…
(just try and ignore the antibiotics and virus bit at the start)