The two best known examples of a systematic attempt to
evaluate the probabilities of finding alien life in the universe are the Fermi
paradox and the Drake equation. They were set up a few decades ago, but were proffered
to calibrate probabilities based only on modelling our galaxy (no further).
Given the less sophisticated technology, they were largely speculative equations
- assessing the rate of star formation, the number of stars with planets, and
the number that are likely habitable. The trouble is, given that there are 100
billion stars in our galaxy alone, and around 100 billion galaxies, both the
Fermi paradox and the Drake equation proved inadequate to the cause of
assessing the fraction of planets with life, and the odds of life becoming
intelligent, and even more so the odds that intelligent life becomes
communicative.
A few years ago, the Breakthrough Listen project was launched, heightening our search for other life in the universe by searching planets that orbit the million stars closest to Earth and the hundred nearest galaxies. This was the biggest and most sophisticated search we've ever had, and has, for me, elicited 5 questions:
1) What are we likely to find out there?
Here's a
hunch - we won't find anything. The universe existed for around 10 billion
years before the earth began to form some 4.6 billion years ago, therefore if
there is intelligent life on other planets much of it is likely to be a lot
more advanced than we are as many of the planets we search will be older. While
this comment makes a lot of assumptions about a similar evolutionary story (see
below), if you imagine how much more advanced we'll be in just 500 years,
consider how much more advanced a civilisation could be that had extra
thousands or even millions of years to evolve.
2) Are we better of not finding each
other?
If such
life does exist, it would perhaps be advanced enough to have been able to find
us by now. Perhaps they are watching us; perhaps they are so
ultra-sophisticated that they have no need to communicate with us, rather like
how we earthlings have no need to communicate with ant colonies. Or perhaps if
they stumble upon us they might see us as enough of a potential threat to
challenge their supremacy in time. In which case they might wipe us out, rather
like how heads of empires used to have their armies wipe out groups of peasant
radicals that saw themselves as revolutionaries and future over-throwers of the
ruling elite.
Alternatively, perhaps alien life out there is less evolved than we are. In which case, mutatis mutandis, judging by the way that we earthlings have treated those who are less-capable and less-powerful than us, if there were such creatures in the universe that are less developed than us, it might be better for them if we never find them.
3) What might aliens look like?
This is an intriguing
question. Presumably any other life in the universe would share the commonality
of having evolved from carbon-based origins (silicon is unlikely). That is to
say, given that science shows that regeneration occurs most optimally at
moderate temperatures, and with an increased amount of chemical variability,
carbon based life is much more probable than any other kind of base. One
presumes creatures on other planets would have had a primordial soup of some
kind - therefore one wonders if natural selection on their planet would produce
anything like us. Given the fecundity of qualities like wings, eyesight, vocal
expressions, a central nervous system, memory and the intelligence to find food
and outcompete rival species - all of which are so fecund that they've evolve
multiple times independently on our planet, one wonders whether evolution on
other planets would select for those same qualities. If we did find life on
other planets, It wouldn't be surprising to me to see them possessing many (if
not all) of the above qualities.
4) What if we miss life by arriving at the wrong time?
I'm not sure I've ever
heard anyone ask this question - but it is worth considering, particularly
after the news that Kepler, NASA space telescope, has discovered a
planet in the Milky Way similar to Earth. NASA said the Earth-like planet,
named Kepler 452b, orbits a star similar to Earth's sun over the course of 385
days, and is located 1,400 light-years away from Earth.
The reason I mention our timing is that even if we do find a planet habitable for life, we have to catch it at the right period of its cosmological evolution. Kepler 452b is 6 billion years old, making it roughly 1.5 billion years older than earth - and it is getting rather hot apparently - just as our own planet will be in several billion years’ time. Given what I said above about how biological evolution selects for fecund qualities and traits that increase the odds of genetic propagation, that 6 billion year period may well have engendered a reasonably high level of intelligent life, only to be gradually discontinued as Kepler 452b gets hotter and hotter, meaning that by the time we discovered it all trace of intelligent life has gone the same way as the evaporated oceans.
5) What are the ramifications for
Christians?
Finally, a
question I pondered a few years ago is whether or not the discovery of alien
life on other planets might affect our religious faith. The first point of note
is that in my experience atheists are bound to find a way to elicit the wrong
accusations on this one. That is to say, when broaching the question of whether
we are alone in the universe or whether there is life elsewhere, one ought to
be mindful, first off, of the way that either answer (‘yes’ and ‘no’) is used
by the atheists (rather dishonestly and disingenuously, as it happens) against
Christianity. They say that if we are the only life in the whole universe then
that must prove that our being here is merely the result of the sheerest fluke.
If, however, there are other planets which contain life of some kind that must
prove that we are not the special creation that the Bible claims we are. Both
contentions are, of course, equally spurious - but it is easy to see how
atheists like to have it all their own way.
So what if we did find sophisticated life on another planet, then, complete with language, intelligence and complex multivariate societies like we have on earth - how would that affect our faith? I think it's a very good question. Suppose they had evolved no concept of God, and had had no incarnation, death on the cross, and resurrection in their history at all - how might you respond to that as a Christian? Could it simply mean that they are another branch of God's creation that do not require the same kind of salvation we do, or perhaps (highly questionably) no act of salvation at all? Or might the absence of God on their planet lead us to wonder if our own religions are simply human inventions? Or, alternatively, might we stick to our faith and accept that there are things we don't understand, and accept perhaps God has not yet chosen to reveal Himself to that planet? After all, sophisticated God-fearing aliens that arrived on our planet 20,000 years ago might think the same about earth.
Personally, my faith is built on so much by way of experience, evidence, cognitive consideration and emotional conviction that I don't think the discovery of a completely God-less civilisation on another planet would shake my faith very much. Of course, the first reaction might be for us to wonder if their being bereft of the good news constitutes an urgent need for us to go share it with them (as per Matthew 28:19-20). But that in itself brings another interesting hypothetical question: is telling the good news to a planet full of people currently unapprised of Jesus actually good news for them or is it bad news? For one presumes that if they had no knowledge of God, they could have no knowledge of sin and their need for salvation. Are they better off remaining ignorant so they are not indicted for their lack of accepting Jesus as their saviour? Would telling them be a bit like taking a deadly pandemic to their planet and then trying to provide them with the cure? Or would not telling them be like leaving them to a pandemic they already have and refusing to take them a cure?
The problem
This blog post has been much more about questions than answers. I am of the view that sometimes questions are more interesting than answers - so hopefully they are questions that got you pondering with interest.