If you have more than a passing interest in the question of whether we are alone in the universe then you may have heard of the Fermi paradox. If you just have a passing interest and haven’t heard of it, read on mes amis!
What is Fermi?
A better question would be who is Fermi, or rather who was Fermi. He was a Noble prize winning physicist who was part of the Manhattan Project, you know the project that created the atomic bomb? He is also a big name when it comes to the quest to find intelligent life due to his infamous paradox.
So what is his paradox?
The paradox says that in theory there should be life in the universe. Why? Well given the amount of stars in our universe is so vast, the chances of there being earth-like planets surrounding some of those stars are also pretty good and given that life happened on earth we can assume life happened on some of those planets too.
Here is where it gets interesting. Our solar system is young. Therefore the human civilisation in terms of the life of the universe is really just a baby. The rest of the universe is thought to be about 13 billion years old. Our solar system is roughly a third of that. Modern humans have only been around for 0.2 million, not billion, years. If there is a wealth of civilisations out there, you have to think they are older and therefore more technically advanced than mankind.
Current estimates say that although our progress towards space travel is slow that we should be able to traverse our galaxy in the next 2 million years or so. By that logic, there should, in theory, be civilisations that could come and visit us. And yet…
Where is everyone?
These are famously the words that Fermi uttered. If the assumptions are correct surely we should have been visited by now? Okay, a small subset of people believes that we have been regularly visited and that the government is keeping it quiet but there is no real consistent evidence to suggest that is remotely true. (sorry Mulder.)
Reasons that the paradox might mean nothing
Of course, this is all a bit anecdotal, isn’t it? Saying there is probably a lot of life in the universe is an easy statement to make. Is there any way of calculating just how common life is? Well, not accurately but there is a method scientist have been using. It is called the Drake equation.
In the Drake equation, several factors are used to ascertain the commonality of intelligent life in our galaxy. It factors in:
- how quickly stars are produced
- Amount of those stars that have planets
- how many of those planets could support life
- how many of those inhabited planets will produce intelligent life
- Amount of those intelligent life forms will develop space travel
- how much time the civilisations spend on sending signals to contact other life forms
The problem with this equation is a lot of the numbers are pure guesswork.
Seriously, where is everyone?
The fact is that there may be life elsewhere but they are busy colonising and have left us alone. We don’t spend our days out having chats with the ant’s nests in our gardens, do we? Perhaps we are so unadvanced that we aren’t worth bothering with. Although as Stephen Hawking commented perhaps it is for the best we haven’t been contacted by another civilisation. He points to mankind’s historical aggressive colonisation and suggests that if we did meet ET he would not come in peace!