The Event Horizon of Alien High Tech

Avi Loeb next to the Great Refractor Telescope at the Harvard College Observatory. (Image credit: POLITICO)In Plato’s Allegory of the Cave, a group of prisoners has been chained inside an underground cavern since childhood. Their legs and necks are bound so they can only look forward at a blank wall. Behind them, a fire blazes, and a raised walkway sits between them and the fire. Puppeteers carry shapes of animals, plants, and objects along this walkway. The prisoners see only the shadows cast onto the wall in front of them, believing these reflections are reality itself.Indeed, our perception of reality is limited. Not only because of the limited abilities of our senses and of the human brain to process all the available data, but also because some information is entirely hidden from view.Einstein’s General Relativity provides examples of information that is permanently locked away behind an event horizon. In these regions, any transmitter of information is running away from us faster than light.This is the case in our Universe right now as the accelerated cosmic expansion carries high-redshift galaxies out of our cosmic event horizon. It is also the case when a star falls into the event horizon of a supermassive black hole. In both cases, the final image freezes on the last snapshot associated with the instant when the source crossed the event horizon. After that time, no additional information is available about the whereabouts of the transmitter of information.This state of affairs also applies metaphorically. Recursive self-improvement can generate acceleration in the cognitive ability of artificial intelligence (AI). In such a case, we might be able to communicate with the AI system up to a limiting speed, which caps our cognitive ability to follow it. This will constitute the event horizon of AI in our technological future.Similarly, if alien intelligence evolved well beyond human intelligence, then we would have difficulties following its reasoning and techn