One of the questions scientists often ask is where all the aliens are.
In a galaxy teeming with planets; why haven’t we been contacted by another civilisation yet?
One astrophysicist has a revolutionary answer to that question: they’re here.
Zaza Osmanov, from the Free University of Tbilisi in Georgia, has suggested in a new study that a race of extraterrestrial beings is using self-replicating probes to explore our galaxy – including the Earth.
He says that a civilisation that’s reached stage 2 on the Kardashev scale, one level above us, would be entirely capable of producing a fleet of Von Neumann probes.
Von Neumann probes – tiny self-replicating robots that harvest resources from planets and asteroids to build new copies of themselves – would rapidly saturate the galaxy. And the probes would make a bee-line for an obvious candidate like the Earth.
“All the results indicate that if one detects a strange object with extremely high values of luminosity increment, that might be a good sign to place the object in the list of extraterrestrial Von Neumann probe candidates,” he wrote in a new scientific paper.
“We have considered the scenario when the Type-II civilisation needs to ‘invade’ the interstellar clouds by means of the self-reproducing robots,” he continued. “And it has been shown that this process will inevitably lead to the observational consequences.”
But when it comes to explaining why we haven’t seen this fleet of probes, Osmanov has a novel and entirely plausible theory: the probes are far smaller than the eye can see.
He says that nanotechnology is the obvious choice for the construction of a probe that is fast moving, quick to build, and adaptable to a wide range of potential landing sites: “We have analysed efficiency of micro scale Von-Neumann probes versus macro robots and we found that the former might efficiently [reproduce] in the interstellar media whereas the large scale automata can replicate only on rocky planets, requiring additional manoeuvring.”
Even if there were billions of these tiny machines scooting through the solar system, we couldn’t detect them with our current instrumentation. Each one would only be about a nanometer in size, which is just one billionth of a metre.
But although the micro-machines are almost invisible due to their size, Osmanov says that there could still be a way to detect them.
If they are powered by light, he theorises, they would emit small amounts of light as they travel across space. When viewed using infrared telescopes, these light streams would appear like the ‘trails’ left behind by comets.