[LINK] "Is it too late for first contact with aliens?"

[rfmcdonald]

Esther Inglis-Arkell's io9 essay does a nice job of outlining the emerging question on the search for extraterrestrial intelligence: why haven't we found them yet?

My gut instinct is that we've been missing some basic information and that, in the near future, we may find out what this information is and what the answer to the question is, but as everyone knows gut instincts are hardly things worthy of making bets on, especially with so little information and such huge stakes.

Every scientific breakthrough has taken time to get going. Knowledge and technology needs to slowly accrue over time until a tipping point is reached. But in some cases, time just isn't a factor. Can we say that some things will never happen because they haven't happened yet?

Case in point: first contact with aliens. Wouldn't it have happened already if it was going to?

There's a famous equation, the Drake Equation, that attempts to figure out exactly how likely it is that humans will make contact with alien life. The equation is a long string of variables. Some variables represent the rate of planet formation and the rate at which life and civilizations evolve. Some variables represent the fraction of planets that can support life, and the fraction of civilizations that develop technology that can competently look for alien civilizations in the universe. The last variable represents how long those societies can last, before they collapse.

In the past, the Drake Equation has been used by doomsayers, who were worried about global nuclear war. The fact that people haven't seen anything yet had to mean, they thought, that societies which develop sufficiently high levels of technology always destroy themselves. Although the apocalyptians still make a decent argument, the fact that the globe hasn't been reduced to ash yet makes it just possible that, instead, we're just coming up against some hard physical limits.

Obviously, the equation is more a thought experiment than an actual solution. At the time that Frank Drake, a astrophysics professor at UC Santa Cruz, thought it up, the world didn't even know that there were more than nine planets (Pluto was still in play). Every single value was an estimate, and continues to be an estimate. Still, the estimates make you wonder. There have to be billions of other Earths out there. What does it mean that no one has contacted us?

Is it too late for first contact with aliens? There's a Catch-22 built into the equation. Because we haven't made contact, the only thing on which we can base the rate of the development of life and technology, from a single cell to SETI, is the Earth. In order to understand properly whether the Earth is slow or fast by universal standards, we have to be able to compare ourselves to other planets — which we can't do until we make contact.

The search for alien life is still in its infancy here. Let's say the Earth holds a relatively fast-developing civilization. Our planet is about four billion years old, a third as old as the universe, so if the other worlds out there are developing at a rate of less than one third Earth speed, it's doubtful they'd be able to receive Earth's signals, let alone contact us back. If, on the other hand, they're developing faster, they should have found us by now. Or we should have found them.

The only thing that could keep them doing so is if it's physically impossible, given the size of the universe, the number of worlds that can develop intelligent life, and the distance between them, to make contact contact other civilizations. Ever.

Saying that, in an infinite universe, if something can happen, it has to happen to us, is verging on lottery-ticket logic. Just because there are a lot of chances for something, doesn't mean that anyone actually has to hit it big. Random chance always plays a part. But there is a case to be made that, if we didn't find intelligent alien life waving a flag and trying to contact us soon after we started looking, we very well might never find it at all.