The scanning for signs of life inside the interstellar asteroid and possible interstellar spacecraft known as Oumuamua has barely started and already a leading astronomer is claiming that the space rock/space ship is possibly a Von Neumann probe. Coupling that name with its cigar shape makes this sound like an unpleasant German medical procedure, but this is the same astronomer who declared that the dimming of Tabby’s star was caused by a Dyson sphere being built around it, so it’s time to do what we did back then and find out what the heck a Von Neumann probe really is.
The astronomer is Dr. Jason Wright from Penn State University and the Von Neumman probe theory appeared in his blog in a discussion over the idea that this may be not lone craft but one of thousands:
“Why would there be so many of them? Part of the argument that it is possible to settle the entire Galaxy is that exponential growth is possible, because the only limiting resource is the stars (and the material around them) themselves. Exponential growth can be achieved via Von Neumann probes: self-replicating spacecraft that go to a system, make lots more of themselves, and then go to more systems.”
The concept is named after Hungarian American mathematician (sometimes called the last great mathematician), physicist and pioneering computer scientist John von Neumann, who spent time researching the concept of self-replicating machines or "Universal Assemblers," which were capable of creating exact copies of themselves. These became known as "von Neumann machines" and, when the theory was applied to spacecraft, “von Neumann probes.” These probes could create new models to continue traveling long distance through space, or they could be programmed to make copies of life forms they encounter.
One physicist and mathematician who liked the idea of the von Neumann probe is none other than Freeman Dyson, theorizer of the Dyson sphere. Dyson used inspiration from the von Neumann probe to imagine a small 1 kg (2.2 lb) craft that would be taken into space by another ship and then released like an egg. The “egg” would “hatch” a solar-powered probe that traveled the solar system, collecting data and samples and powering itself with chemical “nutrients” it picked up. Dyson presented the idea during a lecture in Adelaide, Australia, where an audience member blurted out the name “Astro-chicken” and Dyson liked it enough to use it. While not as well-known as the Dyson sphere, Astrochicken is a concept (small robotic space probes) that is popular among space scientists.
What were we talking about again? Oh, yeah, the interstellar space probe. Dr. Wright proposes that Oumuamua could be a “derelict craft” with broken engines that is slowly tumbling through space without attitude control. However, it could still have a communications system, possibly still capable of replicating itself, that could be generating signals that the astronomers closely observing it this week might pick up. As of this writing, they haven’t heard anything.
Maybe they can’t hear it over the laughter every time someone says “Astrochicken!” or asks if the von Neumann probe is heading for Uranus.