A new research paper uploaded to the arXiv repository on September 1 puts forth an argument that if intelligent extraterrestrials exist, the odds they are actively ignoring us humans is very low.

That falls pretty well in line with other ideas put forth that the chances of other sentient organisms evolving on other planets are astronomically low, and that given the massive size of the universe, it’s very easy to imagine aliens conducting their own search for intelligent life elsewhere to miss us.

Duncan Forgan at the University of St. Andrew in the UK is more interested in an alternative idea for why aliens haven’t found us yet. John Ball, a radio astronomer at MIT, put forth in the 1970s the “zoo hypothesis” that suggests aliens have instead agreed to corral us meek humans for who-knows-what reason.

Forgan decided to run a computer simulation to see what the odds were aliens were in cahoots to keep humanity isolated and alone. He started off with a few assumptions — mostly stemming from the notion that communications between civilizations is limited by the speed of light, and that civilizations could only evolve in habitable zones in their respective star systems.

More complex is running to simulation under parameters that emulate a situation where different alien civilizations can come to an agreement to not talk to Earth. As stated by MIT Technology Review, there are five major parameters that explain the algorithm:

  • First, it sorts the set of all civilizations by arrival time. The first civilization to arrive establishes the first group and is identified as that group’s leader.
  • The computer then tests the causal connection between the leader and all other civilizations in order of arrival time.
  • If a causal connection exists, the civilization joins the leader’s group.
  • If a civilization is not connected to the leader, it begins its own group.
  • Once all civilizations are tested, the model moves to the next civilization that is not connected, and repeats the algorithm until all civilizations belong to a group.

Forgan’s results, when he runs the simulation, find that as time moves forward, the chances of civilizations coming into contact and creating treaties or agreements gets higher and higher. If civilizations last less than a mission years, we’re likely to see multiple galactic groups form up. If civilizations are able to last more than millions years, we are more and more likely to see a single galactic group form up.

Therein lies the issue. The odds that Earth is being ignored is really only possible if all alien civilizations last more than a million years — therefore they form a single galactic group that universally shares the same kinds of beliefs and thoughts behind ignoring Earth. At less than a million years, there is too much diversity that the chances of one or more groups seeking out Earth are much higher.

For the zoo hypothesis to be true, nearly every other civilization in the Milky Way must be very old, and operate under the same belief structure. And this goes against the logical idea that life in the rest of the cosmos will be as culturally diverse as humans are on Earth.