Improbable aliens = Inevitable aliens
A logically valid argument, but that's about all we can say about it for now.
This is a very special edition of my Monday newsletter, which is freely available to all. Paid subscribers also get Tuesday and Thursday editions. Enjoy!
Over the weekend I got together with my friends Richard Saunders (skepticzone.tv) and Fraser Cain (universetoday.com). We sat down and recorded a series of conversations, one of which included an interesting point made by Fraser, who is primarily a science communicator specializing in astronomy. He had watched The UFO Movie and I asked him to share his thoughts.
In my experience, the vast majority of astronomers believe there is abundant life in the universe. I am among them. Fraser, however, sides with those who believe the opposite: that Earth is unique in having life. His rationale for this is anchored in the staggering number of worlds. There are perhaps 2 trillion galaxies, averaging 100 billion stars apiece — that’s some 200,000,000,000,000,000,000,000 (200 quintillion) stars — and we think around 40% of them have planets. That’s a lot of planets, with as many opportunities for life to arise. Using Earth as a model, we find that life in billions of forms has filled every imaginable ecosystem on the planet. To quote Jeff Goldblum’s character from Jurassic Park, “Life finds a way,” and moreover, it finds every possible way.
And then, recall that there are 3rd and 4th generation stars out there, so this number of planets could be doubled or tripled. Through the 14 billion year history of the universe, there have been such an insane number of opportunities for life to arise that it boggles the imagination. This is the basic reason so many astronomers believe there’s a lot of life out there.
But here is the logic that Fraser advocates, elucidated here. Given so many opportunities, some of them would be like Earth, with intelligent beings. Some of these would become spacefaring. Some of these would want to reach out to neighbors. Some of them would engineer multigenerational robotic systems to expand outwards, finding and using resources as they go. Some of these would reach other solar systems, and repeat the model from there. In some of these cases, the speed at which they spread — based on how massively they would have multiplied — could approach the speed of light. Some of these would eventually spread throughout their entire galaxy. Some of these would eventually spread to other galaxies.
We can balk at the extreme improbability of many of those steps. However, when you go back to our starting number, the staggering number of opportunities there are, even the improbable becomes inevitable. Example: if there were a civilization so successful as to be a one-in-a-billion, there would be 50 trillion of them. Civilizations 1,000 times as successful as those would be found 50 billion times. So no matter how improbable a civilization’s expansion is, it’s virtually inevitable.
Therefore, since no robot spread has taken over this galaxy, much less the entire universe, it means no life exists anywhere. Because if life in the universe were a thing, the improbable would be inevitable.
It’s a compelling point, and it’s perfectly valid logically.
However, I don’t find it persuasive, and many astronomers don’t either. An analogy Fraser gave was bugs crossing the Pacific Ocean to colonize an island. Well, floating across an ocean is not a valid analog for interstellar travel. It’s a problem that nobody in the universe has solved, as evidenced by the lack of a United Federation of Planets or self-replicating robot legions everywhere. I believe — and this is informed opinion, not fact — that sticking in and around one’s own solar system is as far as any civilization can go. It’s those pesky laws of physics that prohibit practical interstellar travel.
And the nice thing about my opinion, which is shared by many, is it is still compatible with life being abundant throughout the universe.
This century, space telescopes like the Habitable Worlds Observatory will be able to spot biosignatures and technosignatures of extraterrestrial civilizations. If they do, we’ll have our answer. If they don’t, we will need to start fearing that Fraser may be right.
For a deeper dive, please watch and enjoy my award-winning film The UFO Movie THEY Don’t Want You to See.
=======
The conversations we recorded will be made available on our various channels sometime in the not-too-far-distant future.
Two things to keep in mind, one is the difference between life and intelligent life; and, the other is that this could still be considered a derivative of the Fermi Paradox. I believe a better approach is to try to quantify such probabilities as in the Drake Equation (or Geller Equation).