People have stared up at the sky and wondered for millennia about our place in the universe. We seem to be torn as a species between wanting to claim some exclusive specialness of being the only ‘intelligent’ life and hoping we are not alone. Of course we’ve made up plenty of stories to reassure ourselves of what makes us special along with enough rules to spend our short lives living in fear of getting it wrong.
With telescopes moving from simple lenses in the 17th century to the monster of Hale in the early 20th century, onto Hubble and soon the James Webb, our eyes have opened to the possibility of other planets existing beyond our solar system. It was always only a matter of time (and space) that science and maths would collide in an epic mind job. The numbers are staggering, the Drake equation is starting to look a bit like the homunculus theory of reproduction. Regardless of the formula the probabilities range in the billions of earth like planets in our solar system. Now of course that doesn’t necessarily mean with advanced life (I’d caution using humans as a yardstick). But someone else has done some number crunching that goes something like this:
- For every star in our galaxy there is another galaxy in the universe. For every grain of sand on earth there are 10 000 stars
- If 5% of those are like our sun – that is 500 billion, billion suns like ours
- At least 1% of all stars in universe have earth like planet = 100 billion billion earth like planets
- So, there are 100 earth like planets for every grain of sand
- If we assume only 1% have intelligent life – (advanced civilisation), 10 million billion intelligent civilizations in the universe
- Scaled down for our galaxy that becomes one billion earth like planets and 100 000 advanced intelligent civilizations – just in our galaxy.
Humans are a sad contradiction – afraid to die, and too afraid to truly live. Life is the rule in the universe not the exception. Science has eaten humble pie before although it tends to be laced with amnesia (on a brain that apparently isn’t quite as gendered as first thought).
I kind of imagine with 100 000 advanced civilisations we are well past little-green-men.
Bikes for Fish 
It would be nice to think we are not alone. What worries me is that there is no guarantee that intelligence is inevitable, or a survival advantage, even on Earth. And in amy event, we have a sample size of 1, which is insufficient to generalise. It’s good to dream of the possibilities though.
I like what Carl Sagan has to say ‘absence of evidence is not evidence of absence’. I suppose it also depends a bit on that tricky definition of intelligence. Thanks for commenting Matthew.