One of the inventions that may be realized by advances in nanotechnology is the creation of a von Neumann probe, which is essentially a virus, a self-replicating probe that can then explore the universe near the speed of light.
These hypothetical machines overcome one of the principle objections to Fermi’s Paradox – that it assumes ET would actually want to physically colonize the galaxy. Von Neumann probes allow aliens to explore across vast distances while staying at home.
Essentially, they are self-replicating devices that whizz off and then make copies of themselves, thus rapidly – indeed, exponentially – increasing in numbers and range.
In terms of Fermi’s notion, however, von Neumann probes simply kick the can further down the road. The idea might explain why humans have never seen an alien, but fails to explain why it has never seen an alien machine.
Read full article at:
https://cosmosmagazine.com/space/the-galaxy-might-be-full-of-micro-machines
https://arxiv.org/pdf/1909.05078.pdf
Watch video Michio Kaku: The von Neumann Probe at:
https://www.youtube.com/watch?v=BN-FU8VPoOc