It's late. In Sao Paulo, it's nearing midnight. And, as late nights tend to produce flights of musing about all things cosmic, tonight my blog shall be far out, man.
This week, I've gotten a few things off of my plate. Some practical concerns have been resolved, on a number of fronts. Thusly the mind is freed for the cosmic.
One of the most perplexing dilemmas of modern times is the question of extraterrestrial intelligence. If they're out there, how come nobody except for some borderline nutcases with National Enquirer subscriptions can claim to have met them? Basically, where the fuck are they?
I've been interested in this one for a long time. As long as I can remember being interested in anything. Because it's one of the big ones. You know, afterlife/rotting, God/no god, etc. If we are alone, then Earth is a special miracle (which, as I will argue, it is regardless). If we aren't, then we have to accept another knock down the totem pole of specialness, a process that began with the realization that our planet is not the centre of the universe.
A note for the reader: UFO enthusiasts, flat-earthers, and other nut jobs should get off here. This is a conversation for the logical and the sane.
I'm the kind of guy who likes to admit when he doesn't know something. And I'm going to depart from this generally sound policy tonight. I'm going to make some pronouncements that have the ring of certainty. That is because I am so certain of them, that if I had the money to gamble on them, I would surely make you a wager.
Let me say this: I know why we haven't heard from them. I am sure of it.
To start, let's familiarize ourselves with the Drake Equation. The Drake equation is the brainchild of Frank Drake, a radio-astronomer who got to thinking about these big questions back in the 1960s. He is the pioneer of SETI, the Search for Extraterrestrial Intelligence.
SETI has proven to be a pointless endeavour, it's sad to say. But that doesn't mean it shouldn't have been tried, or that we shouldn't keep trying. Trial and Error is the foundation of science. Smug certainty is the province of religious fanatics. Now, let me continue with my pronouncement of smug certainty.
Drake proposed an equation in which the end product was a postulated number of alien civilizations in the universe. Most of its variables were unknown when it was first postulated. We have had a few more insights since then, but it's mostly still a big question mark. However, the Drake Equation remains the only really useful way to look at this question, to this day. We cannot ignore it. Here are some of the things we must consider:
- How many star systems have habitable planets?
- How many develop simple life forms?
- How many develop intelligence?
- How many intelligences develop technological civilizations?
- How many technological civilizations survive to transmit signals/physically explore the universe?
Short answer: Dunno. Long Answer: See below.
Recent results of telescopic and space probe investigations suggest two things: One, there are lots of planets around other stars, and some of them are in what is known as the "habitable zone," that is, the area where water can exist as a liquid. Two, the potential environments where life can arise are probably a little broader than we once believed. NASA is currently betting on the icy moons of Jupiter and Saturn as the best hosts for life, locked under the frozen surface in subterranean oceans on places like Europa and Enceladus.
Life: Check. It's out there. And soon, we're going to find it.
Life is a normal chemical process arising in certain conditions. These conditions are likely widespread in the universe. Life has likely arisen independently, or cross-pollinated thanks to asteroids and comets, on billions of worlds.
Before you start celebrating and hanging out the "Welcome Alien Friends" banners, hang on a second. We're talking about microbial life here. Microbial life is incredibly hardy and resilient. Multi-cellular creatures are not. Simple life forms exist kilometres down into Earth's crust. Some of them survived three years on the Moon on the Surveyor 3 probe, until the Apollo 12 astronauts brought them home. We're talking tough, folks.
Speaking of the Moon, it's time to talk about it, and why it might just make the Drake Equation a very long bet indeed.
It's pretty conclusively proven that, four billion years ago, a Mars-sized planet hit the early Earth and almost destroyed it. That hit produced the Moon. We owe our existence, I truly believe, to the Moon. The Moon regulates Earth's spin. Its influence keeps our planet on the sort of predictable even keel that is essential to the development of higher forms of life. The happy accident of that early collision has surely been duplicated elsewhere. The Universe is BIG. But we don't see it anywhere else in our Solar System. So, our hopes for Little Green Men take a hit.
They also take a hit if you consider the role of plate tectonics and a magnetic field in protecting life on a planet. The two are interrelated. An active seismic system maintains a dynamic planet. It also produces, through a powerful iron core, a magnetic field which protects a planet from harmful radiation, and preserves its atmosphere. That's why Mars probably used to have life, but doesn't anymore. Lucky again, Earth.
The continued survival and evolution of life is made more likely by a large natural satellite, plate tectonics, and a powerful magnetic field. These factors are considerably rarer than mere presence in a habitable zone.
So, we are winnowing down the numbers of planets whose inhabitants are looking back at us. But surely, there must be some. As Leslie Nielsen would've said: Yes. But don't call me Shirley.
Intelligence. Why did it develop at all? And what do we consider "Intelligent"?
The question misses the point. I think we can agree that Dolphins are pretty damned smart. But they live underwater, so they'll never light a fire, hence, they'll never melt metal, and so much for building rockets or radio telescopes. Technological Intelligence, now that's the point.
This probably comes down to a happy series of accidents. The Chixulub asteroid wiped out the dinosaurs. So our little rodent ancestors got a big break. Millions of years later, climate change forced our ancestors out of the trees. They had to stand up and get smarter to find food. Ten thousand years ago, the end of the last Ice Age made us turn to farming to find even more food, and that was the beginning of civilization. How often does this happen? I'll consider one more element of the Drake Equation before we get there.
The last real question Drake posed was this: So, if we develop intelligence and technology, what are the odds that we actually do something useful with it, before we blow ourselves up?
We've already come close. Several times in the last century, we came close to a thermonuclear war that would have set us back 300 years, if not wiped us out completely. Now, with the possibility of bio-engineered viruses, nano-tech "grey goo," or homicidal Artificial Intelligence, our odds are not looking much better. Plus, we don't seem awfully concerned that we are raising our planet's temperature every year, by continuing to burn dead things, while the means to do otherwise are now quite comfortably in our grasp.
And remember that asteroid that killed our competition? There are still lots out there just like it. And we don't seem to be doing too much about finding them and being ready to blow the shit out of them.
So, maybe that's why there's that big silence in the sky. Maybe lots of planets get smart. They just don't get smart enough, fast enough. Sad. But I suspect it's true.
The development and subsequent survival of technological intelligence are founded on a series of exceedingly rare accidents, reducing the number of potential extraterrestrial contacts drastically.
But all is not lost. My last point is this: The Universe is fucking BIG. The observable Universe is 26 billion light-years from end to end. Within that immense space are quadrillions of galaxies containing an average of 100 billion stars each. All those long odds cannot beat those numbers. Technological civilizations are out there, without a doubt, right now. And they have been there probably since the birth of heavy-metal rich stars like our Sun, enabling them to build tools to make rockets, reactors, and radios.
But here's the last little downer. The Universe is fucking BIG. Since we started sending radio signals into space just over a century ago, we have produced a sphere of radio signature 200 light-years in diameter. If our stellar neighbourhood is populated by even a few civilizations even five hundred years' older than ours, and we haven't heard them, why not? Let's say some of them are a thousand, even five-thousand years older... still: nothing.
The Universe is so big that it is certain to have produced technological civilizations, some of which are still extant. It is also so big that our chances of meeting these civilizations without the development of superluminal travel are practically nil.
For all practical purposes, we are alone. But in truth, we are likely not. I think I'm right. But I hope I'm not.