[FORUM] What do you think is the explanation for the Fermi Paradox?

[rfmcdonald]

Because I seek distraction from the American situation, and because this is a question I'm interested in, I thought I'd raise the Fermi paradox. Universe Today's Fraser Cain had an article, "Where Are All the Alien Robots?", that touched on this. With advances in robotic technology, Von Neumann construction and deployment across galactic distances would seem inevitable.

It makes sense then, for us to eventually get around to sending a robotic spacecraft to another star. Based on our current technology, it’ll be incredibly complicated and expensive, but there’s nothing in the laws of physics that prevents it.

And if we’re going to send a robot to another star system, we might as well make it a factory, capable of creating another version of itself. Find an asteroid with all the raw materials to make more robot factories, and send them off to other stars, where they can make more copies, and so on, and so on.

What I’m describing is the concept of a von Neumann probe, named after the mathematician John von Neumann. He was investigating the implications of self-replicating robots in the 1940s, and imagined non-biological “Universal Assembler”, devices that could make copies of themselves.

Von Neumann didn’t apply the idea to spacecraft, but others like George “Spheres” Dyson understood that out in space, there was a nearly limitless amount of raw materials for spacecraft to build copies of themselves.

Even though the Milky Way measures 120,000 light-years across and contains 100 to 400 billion stars, self-replicating robot factories traveling at just 10% the speed of light could colonize the entire galaxy in about 10 million years. That’s the power of exponential exploration.

Think about it. All it takes is for a single clever alien engineer to craft a single robotic factory. That factory builds copies of itself which fly off to other stars. Once they get there, they build more copies of themselves, and so on and so on.

Seriously, in the 13.8 billion years that the Universe has been around, why didn’t a single alien engineer do this?

What is the explanation? I've touched on this before, here and here. What is the answer for the gap in our understanding of the universe implied by the Fermi Paradox?