Zoo Containment
The Fermi Paradox is the idea that there is a discrepancy between our expectations for intelligent life in the Cosmos based on theoretical calculations, and our observations that we do not see any. This was first proposed as a lunch time problem by the physicist Enrico Fermi in the 1950s.
One of the possible explanations for this is the Zoo hypothesis. That is the suggestion that any extraterrestrial intelligence (ETI) would keep at a distance away from us so as to not interfere in our sociological and technological development but also to deny us knowledge of them. We might consider this a soft zoo hypothesis. It was first suggested in 1973 in a paper that is worth reading: J. Ball, The Zoo Hypothesis, Icarus, 19, 347-349, 1973.
A harder version would see ETI taking direct action to contain us, under the impression that we are a threat to any intelligent life in the Cosmos due to our propensity for warfare and other destructive tendencies. This might involve actions of sabotage against our technological development for example, or hiding data from us that might indicate their presence.
Yet there is a fundamental problem with the zoo hypothesis that has not been discussed widely in the literature. That is how to successfully hide emission signatures from our gaze which might come from anywhere in the Universe? Particularly from electromagnetic radiation such as due to power and propulsion signatures. This might include Bremsstrahlung radiation, Cyclotron or Synchrotron radiation for example associated with fusion reactions.
Over the centuries humanity has developed all sorts of optical telescopes, the latest being the James Webb Space Telescope which is currently in Earth orbit, and is already starting to overtake the Hubble Space Telescope in its discoveries. But there are many other types of telescopes or imaging technologies we have developed that can see through all parts of the electromagnetic spectrum. This includes x-rays, radio waves, ultra-violet…..and it would be near impossible to screen every emission that might travel through space and prevent it from reaching our detectors.
In addition, not only do they have to be screened and filtered out, but also distinguished from any background astrophysical sources for which is the basis of our astronomical program. If we couldn’t detect emission from astrophysical objects we would become suspicious and it certainly would prevent us developing credible physical laws that apply across all time and space.
This suggests that in order to filter and distinguish these emissions, ETI would have to construct a large mega structure perimeter wall around our solar system at a set distance which would be a significant undertaking. Yet it would have to be constructed of a material that was transparent to radiation and yet programmable. Any example of this might be silica aerogel for example with an average density of 20 kg per cubic meter. Yet if for example it was positioned at a distance of 100 Astronomical Units around our sun, and had a thickness of 100 m, this would still have a mass of order 6 times 10^23 kg which is around 1/10th the mass of the Earth. This is definitely a megastructure configuration and would require the resources and technology of a civilization that is much further advanced than our own.
Considering this possibility, as humanity advanced further out the perimeter of the wall would have to change also, which means that it would require constant management and construction, commensurate with our pace of technological advance. This doesn’t seem credible or practical as a strategy for managing a zoo containment strategy around a particular species and its associated solar system.
Therefore if a zoo containment strategy is in operation it is more likely that a softer version is in effect where they simply avoid us. Yet this doesn’t stop us picking up their emissions and over time the case would build for the existence of ETI by our own science program. How then would this be managed?
It would require local management as in by a particular group of humans who are able to control the science programs, what is detected and announced, and how that information is interpreted as a new astrophysical object that had never been seen before. We might call this an ‘Inverse Zoo Hypothesis’, since the zoo containment is being facilitated by humans, where the vast population of the public is kept from the critical information that might indicate an ETI presence. Only time will show if we are living in a zoo of any kind, whilst we float through the void of space locked to a single star and its worlds, yet left wondering what might lay beyond the boundary of our reach.
