This is not a coronavirus post. You’ve seen and heard enough of that by now. I’ve seen and heard enough of that by now. So I thought I’d abruptly change the subject to one of the most fundamental questions of human existence: are we alone in the universe? I suppose social distancing might be making some of us feel that way. Sorry, I promised this would not be a coronavirus post.
There are really two levels to the question of whether life exists elsewhere. The first level is whether it exists at all elsewhere – even if it’s entirely confined to bacteria and algae. Of course, the most powerful living thing on Earth right now is not even a living thing, it’s a virus. Sorry, I keep forgetting this is not a coronavirus post.
The second level of the question is whether intelligent life exists elsewhere – meaning life that has become self aware, able to communicate amongst its individual beings, and possibly even able to communicate or travel beyond its home planet. I’ve generally been uncertain about whether intelligent life actually exists here, on Earth. Recent events have convinced me it generally does not. If it did, people would not be saying things like “this is no different from the flu” and “I just realized in early April that it can spread from people with no symptoms”. Dammit, there I go again.
Fine. It’s a coronavirus post. One thing I was hoping would happen amidst this pandemic is that it would bring our polarized world closer together as we fight a common enemy. Unfortunately, it has done just the opposite. In particular, red and blue states have never been redder or bluer. Put more directly, rural and urban have never been more rural or urban. The way viruses spread is a very big reason: there are more people in urban areas, and more of them are also closer together more often. That means it’s going to do its worst damage in cities, leaving many people who live in suburbia or on a farm to wonder what the big deal is.
So I was wondering, what would it take to bring us all together against a common enemy? And then I thought, what if a hostile alien civilization attacked our planet? For certainly that would be indiscriminate enough to convince us that we shouldn’t be attacking each other anymore. Nor should we be wasting our time looking for reasons to ignore the threat. Yet as the idea gained momentum in my mind, I thought about it a little more, and suddenly I couldn’t get “Independence Day” out of my head, where the invaders attack all the major cities first, so people in Montana would probably – again – be wondering what the big deal is, and now I’m back to square one on this post. Or am I? But maybe the most important point to all of this is that I started each sentence in this paragraph with one of the seven coordinating conjunctions.
If that doesn’t set me up for a Pulitzer, then the whole system is rigged.
Ok back to the search for intelligent life, and why it’s more important to humans than we might think. At this very moment, I am remembering all the way back to Sunday evenings in my childhood, when I first heard Carl Sagan talk about the search for intelligent life as part of the “Cosmos” series. The point of it all wasn’t some philosophical discussion – nor was it a way to gauge our fear of being attacked. It was about hope. Not hope of meeting another species in and of itself, but hope that we can get through this ourselves. The coronavirus is just the latest threat to our species as a whole. The virus alone won’t extinguish us, but you can probably see that if societies don’t deal with it properly, they could break down to the point where we find another way to go off the rails. And imagine if an even more lethal disease like Ebola were to become as infectious as COVID-19.
More broadly speaking, viruses are just one kind of threat that can rise to a global scale. Nuclear war and climate change are some wonderful man-made examples. But we could do everything right, and still be wiped out by a gamma ray burst or a hurtling rock from the depths of space. Or a hostile alien race could arrive and discover that Jeff Goldblum, Will Smith, Randy Quaid, and Bill Pullman are no longer able to protect us quite as well as they could in the mid 90’s.
So it’s fair to wonder, not only is there life elsewhere, and not only has that life become intelligent, but has it managed to survive all these threats? And this is where we turn to Drake.
No, the other one.
I’m talking about Frank Drake, an American astronomer and astrophysicist who created a mathematical equation in 1961 that has spurred rigorous debate ever since. The Drake equation is a framework for debating the likelihood that other civilizations exist in the galaxy with a sufficient level of technology that they could communicate with us (and others).
Here is the equation in all of its glory:
N = R* × fp × ne × fl × fi × fc × L
In this equation, N represents the number of active, communicative extraterrestrial civilizations in the Milky Way galaxy. Since we have been transmitting television signals into space for many decades now, we are one of those civilizations. So we know N is at least 1. To determine if it is any higher than that, we have to calculate and multiply all of the other items to the right of the equal sign. The next several posts on this blog will go through each of those items in detail, but for now, here is what they are:
R* is the rate at which new stars are created in our galaxy
fp is the fraction of stars that have planets
ne is the average number of planets per star that might support life
fl is the fraction of life-supporting planets that actually develop life
fi is the fraction of developed life that becomes intelligent
fc is the the fraction of intelligent life that sends signals into space
L is how long a signal-sending civilization survives and sends those signals
There are a number of criteria one could develop to determine if a civilization is intelligent. It is difficult to imagine an intelligent civilization not being able to do math. So it is fitting that we can use math to determine just how many intelligent civilizations there might be. Math can be quite scary, as those who have actually done the math for COVID-19 have discovered. But math can also give us hope. In either case, it makes us more aware, and that’s certainly a start.