In the middle of a pandemic, it’s fair to ask why I’ve spent the last several posts in this blog trying to calculate how many other civilizations are out there in the galaxy. One perfectly good reason is to talk about something else for a change. But now I’m going to ruin that and tie it right back to the pandemic.
COVID-19 is only the latest threat to large numbers of humans. Like some other threats, there is an element of COVID-19 we had no ability to control. But also like most other threats, we typically don’t make things better by our actions. And of course we have come up with threats entirely of our own making – like global thermonuclear warfare, for example. Not all of these threats would extinguish our species if realized, but some of them could. We’ve seen in our tour of the Drake equation that mass extinctions have happened at remarkably regular intervals on Earth – often wiping out a very high percentage of species at once. Earth has undergone its own dramatic changes to the climate, but we are the first species to consciously introduce our own changes, and we don’t know where the tipping points are. Meanwhile, at some point, another rock will hit our planet, just as one did millions of years ago to spell the dinosaurs’ doom. Depending on the size of that rock, we might survive, but we also might not.
So there is a very real question about how long we will be around on this world. Will we last long enough to venture out into deeper space? Will we get a chance to colonize Mars? And then perhaps visit other star systems? And maybe even encounter intelligent life on other worlds? What kind of imprint will humanity leave on the galaxy when all is said and done? Or will we leave nothing more than a hundred or so years of garbled radio and TV broadcasts that dissipate into thinner and indecipherable wisps as they spread into the void?
To answer those questions, it sure would be nice to know how other civilizations have fared. By the time we got to the next-to-the-last step in the Drake equation, we had estimated that once every three years in our galaxy, a star is formed that will one day see a civilization rise up on one of its worlds and send signals into space. So at least going in, it seems like there ought to be a lot of civilizations that get to that point. The last factor in the Drake equation – how long a typical civilization lasts – is the big wild card, and the one we are grappling with ourselves. Should we be worried that we haven’t heard from anyone else as yet?
Now, there is always the notion that we *have* heard – maybe even from a *lot* of them – and that aliens and/or our government(s) have covered that up. I’m not going to be arrogant enough to completely dismiss that possibility. There is a chance – however small one might choose to characterize it – that just such a thing is happening here and now. If so, there are two things we can say: 1) We were bang on with our Drake equation, and 2) There isn’t a damned thing any of us can do about it. If the governments of our world are airtight enough to have kept us from the light – and given their incompetence in many other matters, I would be rather surprised – then that is likely to continue for quite some time. If it’s the aliens themselves that are keeping us in the dark, well, basically same point, rinse and repeat.
Let’s explore the alternative instead – that we simply haven’t heard from another civilization yet, and whether that is a problem. Sometime back in the year 1950, the brilliant physicist Enrico Fermi was having lunch with a few other intellectual giants, and the conversation arrived at the question of extraterrestrial intelligent life. Depending on the account, Fermi eventually exclaimed something along the lines of “but where are they?” That question eventually came to be known as the Fermi paradox: it would seem (as we have calculated in this series of posts) that there ought to be lots of intelligent life out there, and yet despite considerable attention and effort, we have not found any – nor has it found us, as far as we can tell.
There are different categories of dealing with this paradox. First – perhaps we were simply wrong in the Drake equation. Maybe what happened on Earth is extremely rare. Or maybe the fact that we’re so close to the edge of our Goldilocks zone – to the point where a lot of our water is vapor in the atmosphere – has made dwelling on land a possibility when it usually isn’t elsewhere. Would creatures like dolphins be able to develop space communications technology on a world completely covered by water?
Another line of thinking is that the last term in the Drake equation – how long a civilization survives – is truly constrained to a few hundred years because intelligent life always ends up destroying itself (either deliberately or by exhausting all available resources). Yet another thought is that many civilizations don’t want to communicate or be discovered. And yet another thought is that other civilizations have indeed found us, but they are more advanced and they don’t want to disturb our natural evolution toward whatever end.
There are so many different directions to go with all this. For myself, it would ultimately seem to boil down to a combination of two main things:
- The “lottery” of speaking and listening between civilizations: we cannot transmit deliberate signals in every direction at once and/or all the time, and we cannot listen to signals in every direction at once and/or all the time. Any other civilization is in the same boat, and each of them is at a different point in their respective history where they may or may not have the ability and/or the inclination to send a signal. So the likelihood of them transmitting at us and us listening from that exact direction at the precise moment when it arrives actually turns out to be pretty small, even if there are millions in the galaxy at any given moment.
- Somewhat related to (1) – the commitment. The amount of effort we have expended on the search for extraterrestrial intelligence is miniscule compared to the effort we have expended on other things. It would take orders of magnitude more effort – and commitments of life at the scale of generations by the participants – to actually go out there and visit other star systems. Meanwhile, we have only sent a handful of purposeful signals out there to reveal our own existence.
I guess what I’m saying here is that in my opinion, the Fermi paradox isn’t a paradox at all – we should expect finding another civilization to be just as difficult as it seems, even if there are millions of them in our galaxy alone. But if it’s important enough to us, perhaps we should ramp up on item (2) above – our commitment. The most famous organization exploring these questions – the Search for Extraterrestrial Intelligence (SETI) institute – receives zero funding from the Government. It is entirely financed by private donations. It would seem like this endeavor would be worthy of more systematic support than that – finding such hope from somewhere and someone else might be the most impactful thing we could do as a species to redouble our focus and work our way through the variety of crises we face today.
For now, it is my own hope that someday, we or our descendants will have a light chuckle at the idea a brilliant physicist once had to ask “but where are they?”