Interstellar communication. IV. Benchmarking information carriers

TL;DR

This paper compares various potential information carriers for interstellar communication, finding photons generally superior in speed and efficiency, but exploring conditions where alternative carriers might be advantageous.

Contribution

It provides a comprehensive benchmarking of different interstellar communication methods, including non-photon carriers, highlighting their advantages and limitations.

Findings

Photons outperform other carriers in speed and energy efficiency.

Inscribed matter requires less energy but has higher latency.

Current technology is insufficient to determine the best low-data-rate beacons.

Abstract

The search for extraterrestrial communication has mainly focused on microwave photons since the 1950s. We compare other high speed information carriers to photons, such as electrons, protons, and neutrinos, gravitational waves, inscribed matter, and artificial megastructures such as occulters. The performance card includes the speed of exchange, information per energy and machine sizes, lensing performance, cost, and complexity. In fast point-to-point communications, photons are superior to other carriers by orders of magnitude. Sending probes with inscribed matter requires less energy, but has higher latency. For isotropic beacons with low data rates, our current technological level is insufficient to determine the best choice. We discuss cases where our initial assumptions do not apply, and describe the required properties of hypothetical particles to win over photons.