What is a Von Neumann Probe?

Image from the Hubble Telescope.

Hey everybody, it's Thursday and I'm back with another update. Today I'd like to ramble a bit more about a subject that I talked about a few months ago - The Fermi Paradox. I discussed it there in general terms and brought up a number of subtopics, one being the Von Neumann Probe, which I will expand upon here.

In simple terms, a Von Neumann Probe is a type of theoretical robotic automaton that roams outer space seeking out resources in order to reproduce itself. Machines like these have been the subject of many science fiction stories, and they are often portrayed as violent and dangerous entities (see the Reapers from Mass Effect for reference).

The reason why they are often brought up alongside the Fermi Paradox is because the two are closely related. Assuming an intelligent alien species wanted to "colonize" the galaxy in the most efficient non-faster-than-light method, the best way to do so (again, by our limited understanding) would be to send out Von Neumann probes to slowly but steadily explore and extract resources from every inch of the galaxy.

Even at speeds far below that of light, these machines would be able to span the 100,000 light year diameter of The Milky Way in a few million years. Seeing as our universe is approximately 13 billion years old, you would assume some alien race would have done something like this by now. The fact that they have not may prove that we are alone in space (or at the very least, the only intelligent species).

There are several possible reasons to as to why we have not yet detected Von Neumann probes.

For one, there could be a form of "berserker" Von Neumann probe out there that eradicates any alien species with the technology sufficient to create probes of their own.

Why would they do this? Perhaps they wish to keep their monopoly on galactic resources, and don't wish to have any competition. And why don't they wipe out all life completely instead of waiting until they've reached a certain technological level? Perhaps it is cost efficient to do so, or maybe they gain some other benefit from doing so.

Either way, the berserker probe is an important concept to keep in mind when thinking about the possibilities of extra terrestrial life and the inherent dangers of space exploration.

With private companies like SpaceX making their first successful forays into space, it is only a matter of time before we gain the technology and ability to take on a greater role within the Milky Way. That may not be for a hundred years or even five hundred, but either way, as long as we do not kill ourselves off first humanity will eventually spread beyond the boundaries of Earth's atmosphere.

When that day comes, and we take our first steps into the endless stellar expanse, we'll have to hope and pray that the universe is not as dangerous a place as so many scientific theories make it out to be.