So I have spoken at length about the Fermi Paradox quite a few times, including this cool video that outlines the basis of the theory. There are literally hundreds of theories that could qualify as a viable solution to one of the most bizarre conundrums that humans have encountered in the universe. What I have never talked about is the man behind the paradox, Enrico Fermi and how this paradox of his came about.
I found this interesting article that talks more about how this theory came into popular culture. The article states that Fermi never really said what the famous paradox is named for him states. In fact the article says that Fermi more or less made a passing statement that has seemingly stuck with him. While eating lunch with friends he asked:
“Where is everybody?… he went on to conclude that the reason that we hadn’t been visited might be that interstellar flight is impossible, or, if it is possible, always judged to be not worth the effort, or technological civilization doesn’t last long enough for it to happen.”
The article goes on to say that while Fermi does certainly question the existence of technologically advanced extraterrestrials, the article makes the assertion that Fermi, with his statement above, was more so questioning the feasibility of interstellar travel. So if that is the case, where did this paradox come from?
Enter astronomer Michael Hart who said “that if smart aliens existed, they would inevitably colonize the Milky Way. If they existed anywhere, they would be here. Since they aren’t, Hart concluded that humans are probably the only intelligent life in our galaxy, so that looking for intelligent life elsewhere is “probably a waste of time and money.”
These comments were elaborated on once again when discussing the ability to colonize an entire solar system by a physicist Frank Tipler. “A self-replicating universal constructor with intelligence comparable to the human level.” Just send one of these babies out to a neighboring star, tell it to build copies of itself using local materials, and send the copies on to other stars until the Galaxy is crawling with them.
From these two statements the article says that the so called Fermi Paradox should probably be named for Hart and Tipler. Just a little did you know for the day. With all that being said, Hart’s idea sounds like the Von Neumann Machines that were first discussed by John von Neumann. So, I guess technically this theory should be called The Hart Tipler von Neumann Paradox, that certainly rolls off your tongue and into your heart.
Moving on. Now that we have that out of the way let’s look at some of theories that are stated above.
Let’s start with what Fermi originally said. Is interstellar travel possible? First, he said this at a time when NASA and space flight itself was not yet a thing, so as the article states, it is easy to see why he would be pessimistic on this idea. We now know that theoretically there is nothing to prohibit interstellar travel. However, currently we certainly do not have the technology to send humans to anything (as I make that statement the Voyager Probe is currently at the edge of our solar system) outside our solar system. Still though you have to wonder as so much of what we think we know about the universe is theories, things that can only be disproven, it makes me wonder if there is something in deep space that we have not discovered that makes interstellar travel impossible. I have no idea what this might be, but the fact that we have put our faith in so many theories sort of makes me lean just a little into the camp of maybe, just perhaps, there is a small chance that interstellar travel is not possible. With that being said there is the ever present “X” factor, and that is technology. Again, theoretically, there could be any number of advanced technological devices that could skirt many of the laws of physics in our universe, without breaking them, and circumvent the problems of interstellar travel.
Hart on the other hand I think seems to make some pretty outlandish claims. Basically, just because we don’t see or hear anyone that we are alone and we are the only life in our galaxy. While he may be correct in his final assertion, his logic and analysis I think are a bit silly or outlandish at best. Recently, I read that if there is life in our galaxy that it would probably be closer to the center of the Milky Way. We are currently floating on an arm of our galaxy, and I do not know if we have the technology to listen or observe planets or stars closer to the center of our galaxy. So again he may be correct, I just do not agree with his logic. Basically he may be right but for the wrong reasons. There may be tons of life in our galaxy, but they may not have made it out to the cosmological suburbs where we live.
Of all the statements, Tipler’s is a bit more intriguing for the simple fact that it just comes down to the numbers and numbers never lie. For all the research in the article I am surprised they did not mention John von Neumann, but o well. Tipler basically says that if we had the technology to build a robot or probe of some kind that could use materials it found and make an exact copy of itself, such a robot could colonize an entire galaxy in a relatively short amount of time. Look at it as one makes two, two makes four, four makes eight, eight makes sixteen so no and so forth. The point is that eventually given enough time, a galaxy will be crawling with these probes. I have seen where a self-replicating probes could spread through a galaxy the size of the Milk Way in as little as 500,000 years (Wikipedia). Which is relatively quick, cosmically speaking. So if that is the case why haven’t we encountered anything like this on Earth?
I think that is a pretty valid question for the most part. But again there is so much that we do not know. Perhaps an intelligent civilization would not want to create these probes because they did not see the point, that is a very simple answer to a complex question. Or maybe they have achieved interstellar travel with ease, so the probes would be mostly pointless.
As I mentioned above there are literally infinite possibilities when it comes the search for intelligent life. I feel like it is much like winning the lottery, there are millions of way for it not to happen, but only one way to win. Obviously we are still looking for that single win. In terms of the universe the odds are extraordinarily stacked against us.