“Detection of Complex, Electromagnetic Markers of Technology”
We propose to extend work of the PI and CO-I that developed widely used methods for detecting simple signal types characteristic of our civilization 1,2. These signals, if present in other stellar systems, are highly distinguishable markers of an advanced biology, one that has produced intelligent electromagnetic signals. As our civilization’s communication technology has evolved, demands for efficient use of the electromagnetic spectrum has resulted in an ever- higher proportion of signals with complex forms of encoding 2. Thus, the ensemble of terrestrial signals today consists of both “simple” signals, ones with well defined prominent characteristics, and complex signals, those spread in frequency and time. If this proposed development leads to effective discriminators for complicated signals, we will use prototype and advanced instruments to complement current detection of simple signal types. This will be demonstrated using complex discriminators combined with detectors for simple signals on a telescope of advanced design, the Allen Telescope Array (ATA). Thus, the biomarkers of advanced technology may be simultaneous detection of a collection of simple and complex signals originating from a planet orbiting a Sun-like star.
In general, the search for extraterrestrial intelligence (SETI) is a search for technology orbiting distant stars. If the Earth is typical, the most striking electromagnetic evidence of technology may well be microwave signals, which can, over their transmission frequencies, outshine stars by a factor of a million. This is because our signals contain strong, concentrated components, and because stars transmit most of their energy in the visible region, not the microwave region, of the electromagnetic spectrum.