A von Neumann probe is a kind of self-replicating spacecraft. From the linked Wikiepdia article:

In theory, a self-replicating spacecraft could be sent to a neighbouring planetary system, where it would seek out raw materials (extracted from asteroids, moons, gas giants, etc.) to create replicas of itself. These replicas would then be sent out to other planetary systems.

The possibility of such probes, and the fact that we haven’t encountered any yet has interesting implications for the Fermi Paradox:

Even without traveling anywhere near the speed of light, this process would colonize the whole galaxy in 3.75 million years, a relative blink of an eye when talking in the scale of billions of years:

There are several possible explanations for the apparent absence of von Neumann probe, some of which are tied to the usual proposed resolutions of the Fermi Paradox. It may be that intelligent life is so rare that we are alone in our galaxy. Or it might be the case that all organic intelligent life’s technological progression is such that it develops (and is supplanted by) super-intelligent AI before it develops interstellar travel. The resulting AIs may not be interested in physically hauling mass around the cosmos and are content to exist in supercomputers powered by their home stars. Or, as Carl Sagan proposed, advanced civilizations may choose not to create von Neumann probes and even actively destroy any they encounter because they are seen as dangerous.

Ok, but what are the implications of all this for “Steven Universe”? Are the gems von Neumann probes or not? I don’t think so.

While the gems do use a planet’s resources (”suck the life right out of the ground”) to replicate, what we know about their dispersal pattern doesn’t really fit the proposed behavior of von Neumann probes (see the branching structure in the first image). Von Neumann probes spread ever outward, never returning to their planet of origin.

The gems, however, seem to mostly operate out of their home planet and are able to use warp pads and interstellar FTL spaceships to move back and forth between planets at will. More of a hub and spoke system.



Rather than simply spreading as far as possible, the gems’ goal seems to be to use other planets’ resources to benefit the homeworld. They are able to exploit other planets’ resources with minimal opposition because of their technological superiority. Sound familiar? The gem aren’t probes. They’re colonizers.



That said, we don’t really know anything about gems’ activities on other planets. If we later learn that gems born on Earth went on to colonize other planets, without returning to the homeworld, that would bring them more in line with the definition of von Neuman probes.