If alien civilizations use hyper-efficient computers, they will have a distinct energy signal we can detect

The author of a new paper argues that advanced alien civilizations could generate a distinct energy signal detectable from Earth via their hyper-efficient computers. This signal, dubbed a "Slysh halo," would be a byproduct of extremely efficient and cold computing. The concept is rooted in the principle that computations generate waste heat, and the colder the computation, the more efficient it is.

At temperatures near absolute zero, computers could be up to 30 times more efficient compared to room-temperature operations. The author posits that such highly efficient computers would radiate heat in the far-infrared or submillimeter spectrum. However, the heat signature of a civilization's star would have to be distinguished from that of debris encircling it, such as the Oort cloud around our sun.

Despite this challenge, a fully optimized Slysh halo would be bright enough to be detected from as close as 100 light-years away, potentially discernible with current telescopes like ALMA. As more advanced instruments become available, the likelihood of detecting a Slysh halo increases. If such a signal is not found, it would suggest the absence of nearby alien civilizations.