The Italian physicist Enrico Fermi (1901 – 1954) created the first nuclear reactor, worked on the Manhattan project, and is one of only 16 scientists in history to have an element named in his honour. It’s fair to say that he’s a big deal in science circles.

One of the many things for which Fermi is famous came about as a seemingly simple question, raised during a conversation with colleagues. It went like this: According to the Drake Equation, the universe should be teeming with intelligent life. The numbers certainly seem to say so. Fermi is credited with asking the question. “OK, if there are so many species out there…where are they?”

This question, known now as Fermi’s Paradox, is a good one. Since there are billions of stars in the galaxy, there is a high probability (now proven by NASA) that some of them will have Earth-like planets. The laws of probability argue that some of those should develop intelligent life. Some may go on to develop interstellar travel in some form. The Milky Way galaxy could in theory be completely traversed in a few million years. So, again… where are they?

Disregarding science fiction instant travel scenarios like Stargates and transporters, we have yet to go beyond theory ourselves. For all we know, our theoretical space travel options may never pan out. They could prove to be scientific dead ends, impractical to achieve in the real world, or as way off the mark as geocentricism and alchemy.

But that may not be the only reason we haven’t met our neighbours. Let’s assume that the universe really is teeming with intelligent life, and ask the same question: Where are they?

This planet on which we live is fairly young, cosmically speaking. Allegedly intelligent life (that’s us, by the way) formed a few seconds ago, in the scheme of things. We went from caveman to spaceman in the blink of an eye.

Before cars, trains, rockets and ships, we had feet and, when we grew clever enough to think of it, horses. Exploding across the face of the planet, we hairy mammals went forth and multiplied. It’s what we do. We did it on every major land mass pretty much simultaneously. There are some thing we do really well.

I am from England. My pre-Roman ancestors wandered around in animal skins and howled at the moon (some still do). For them, there was only day and night and food and sleep and death. And when they reached the shore of the sea, the English Channel, they stopped. That water was an insurmountable barrier. Just like space.

From the famous White Cliffs of Dover in England, it is possible, on a clear day, to see the coast of France. There is no way for a caveman to ever reach that shore. It may as well be the moon.

On the other shore stands another caveman looking over to the cliffs of Dover. He can see it, but not reach it. Both are asking themselves the same question: What can I eat? Cavemen are notoriously practical. Neither can see the other. But my ancestor, while chewing berries, may pause to wonder. Is there life in France?

Or in England? That French caveman probably asked himself the same question. Both would be convinced they were alone in the universe. This same melancholy thought would occur to every caveman on every beach, in every country, across the face of the Earth. There may be countless civilizations out there having that thought as I type. They can see the other shore but think it empty. Now, there’s a thought, eh?

Throughout history explorers have ‘discovered’ new lands and cultures. When my ancestors reached France, they found other cavemen. Marco Polo, Magellan, Columbus. Every intrepid adventurer soon discovers that far away lands are, almost without exception, already populated. Life is like that. And I see no reason to think that this rule should end at the edge of the atmosphere of this small blue rock.

Just because we do not have visitors landing in our parks demanding to be taken to our leaders does not mean that they are not there. It does not mean they can’t see our planet. It doesn’t even mean that they aren’t watching I Love Lucy reruns. It may be that, like us, they just haven’t figured out yet how to cross that sea. This is a young galaxy. Life is young. Give it time.

NASA has identified many planets capable of supporting life as we know it, and finds more every day. We may have already seen the home planet of a real life civilization. We just don’t know it.

For all of our achievement and progress over the centuries, in many ways the human race remain cavemen. So here’s a parting thought.

We’re still on those cliffs looking across to France.
And, perhaps, some other cavemen are looking back.