Fermi paradox: Early in the Game

One of the more interesting solutions to the vermi paradox is the notion that the reason behind the great silence we see as we study the cosmos so far is that we've simply appeared incredibly early in the history of the universe. This has two implications. The first is that the galaxy is our oyster to colonize and inhabit as much as proves possible in the far human future. The other is that since we may actually be from the earliest time possible for a civilization to form, it's also on the table that an explosion of intelligence may be coming to the universe. We have some indicators of this here on earth. For much of the history of life on earth, it wasn't intelligent. In fact, it was mostly microbial. Yet as time has progressed, more and more intelligent animals have appeared, to the point that one could easily see a day in the far future where earth is a multi-intelligent species planet, populated with humans, but also advanced dolphins and perhaps whales, or even some of the cephalopods eventually. And that's without us uplifting them, but rather an apparent natural progression towards intelligence on this world. Of course, that could get reset very easily, and trend the other way. As the sun's increasing luminosity makes conditions less hospitable for life on earth, this will be the case. This will someday, for a time, become an entirely microbial planet once more. And it's worth remembering that if whatever caused the disappearance of other advanced hominids in the past hadn't happened, we'd have a planet with multiple species of human populating it today. That's an interesting world to imagine indeed. But as for the universe, the fact is, it's almost brand new compared to its total possible lifetime. At just roughly 13.8 billion years after the big bang, our universe literally has trillions of years to go before we can start calling it dead, opening the way for many, many more chances for life to arise within it, more than it's had so far. But the key question here is how long has it been able to sustain life? This is where it gets a bit odd. The universe has actually been able to do it twice. One opportunity for life very early in its history, and one going on right now, but the two are distinct. The first of these is known as the epoch of habitability in the early universe. Advanced in a paper by Avi Loeb, link below, this period, about 10 to 17 million years after the big bang, allowed, in principle, for any planet in the universe to have liquid water on its surface, regardless if it was around a star or not, due to the residual heat left over from the big bang. As a result, in principle, this might have allowed for the conditions needed for life to arise that early in the history of the universe. But the window was small, and it remains highly unlikely that there actually were any planets present in the universe at that time, the materials needed for that came much later. And when this epoch ended, if life magically did arise, it's long dead and gone, and not likely to still be around. But at least, in principle, the universe has seen several periods of habitability. And that brings up the current period of habitability, which is a much longer period of time. Up until recently, it's always been thought that the Milky Way has been producing planets capable of harboring life for billions of years longer than earth has existed. But this may not actually be the case, and that very old star systems in the Milky Way capable of harboring life may in fact be somewhat scarce. If that's the case, the solution to the Fermi Paradox could simply be that we're early comers to the galaxy. This idea has to do with galactic interactions. Galaxies over the course of their history often undergo collisions with other galaxies, almost routinely over very long periods of time. The Milky Way is no exception, and in fact is set to collide with the great Andromeda galaxy in the far future. But one specific interaction that's been going on for a long while is that of the Sagittarius dwarf galaxy. We didn't know about this small galaxy until the 1990s. But from there, a story unfolded that was quite dramatic. This galaxy keeps repeatedly slamming into the Milky Way through gravitational attraction, and has done so for billions of years. Not only have these collisions possibly helped form the barred spiral structure of our galaxy today, but they may have also had a hand in the formation of the sun and the solar system. The idea is that each time the Sagittarius galaxy smashes into the Milky Way, it sparks off a period of star formation by agitating the gas and dust of the Milky Way. Each time that happens, it essentially results in a burst of stars appearing after each collision. This also affects metallicity in stars and the galaxy at large. So it may be that before the interactions with the Sagittarius dwarf, most stars in the Milky Way were metal-poor and not likely to form planets. This has implications on past habitability as there may have been fewer chances for star systems to form that could harbor life, and thus might have hampered the appearance of intelligent alien civilizations until relatively recently. Now it's also possible that we are still not alone, and we have contemporaries in the galaxy of about the same age. And there still could be civilizations out there millions or even a few billion years older than we are. But that assumes that intelligent life is common. We don't know that it is. So while very rare in this scenario, other alien life is still on the table. But it could just as easily be that we are the first. And while that would seem lonely, it does allow for an interesting speculative future indeed. This would be a far future where we may be long gone, but some of our artifacts may still exist. Future alien civilizations colonizing the galaxy might find bits and pieces of evidence of humans in the distant past. And we end up being the mysterious ancient civilization. This will actually be harder than it sounds. Earth is a hostile environment for preserving things most of the time. What evidence of us that doesn't rust or weather away eventually may simply get subducted through plate tectonics and destroyed. But there are places in the solar system where artifacts can last much longer. Ideal here is the moon. The lunar surface changes very little, only gradually getting gardened and slowly disturbed and pulverized by micrometeoroids, and with the occasional large impact. It has been advanced in astrobiology that this would make for an ideal place to bury an artifact, in which case beneath the lunar soil objects could last indefinitely, perhaps billions of years, and that it might be the place to look for anything left by past civilizations passing through the solar system. But the same rules apply to us. We have already placed various pieces of technology on the moon, bits and pieces of which may end up buried, and might be found by some future alien metal detectorist. But there are also possibly artifacts of humanity already buried on the moon. Case in point, during the Apollo 11 moon landing, the United States wasn't the only nation trying to return rock samples. The Soviets were also pursuing this, and had launched the Luna 15 probe concurrent with Apollo. And in fact, this probe crashed onto the moon while the astronauts were still on the surface. It's conceivable that bits of metal, very obviously of a composition unlikely to occur in nature, could have become buried from this, or other moon missions. These bits of metal may be a great puzzle for future intelligent aliens trying to glean whatever they can from the bits and pieces they've found regarding our past presence in the solar system. We would largely be a mystery, however. And said aliens may not even know what we looked like. They would simply know that we were technological, likely from the third planet from the sun, and were spacefaring. Or to speculate further, the aliens may be us, and millions of years from now may not even be recognizable as human. And if somehow our early history had been lost or forgotten, they might not even know they were related to us. Or even might have once been members of another of earth's species. Spacefaring dolphins, indeed. Thanks for listening! I am futurist and science fiction author John Michael Godier currently concerned about what the aliens might think if the right artifacts preserve. I'd imagine my beard trimmer would be a mystery. Or how about a youtube silver play button? What was this event horizon show about? They might think we were some really weird aliens. And be sure to check out my books at your favorite online book retailer and subscribe to my channels for regular, in-depth explorations into the interesting, weird and unknown aspects of this amazing universe in which we live.