Transmitting signals over interstellar distances: Three approaches compared in the context of the Drake equation

TL;DR

This paper compares radio, laser, and artificial transit methods for interstellar communication, analyzing their energy efficiency and longevity, highlighting the trade-offs for long-term signal transmission.

Contribution

It provides a quantitative comparison of three interstellar transmission methods based on energy and time, emphasizing the potential of artificial transits for long-term signaling.

Findings

Radio transmitters are most energy-efficient.

Artificial transits can transmit signals for durations exceeding civilization lifetimes.

Laser methods are less emphasized in the comparison.

Abstract

I compare three methods for transmitting signals over interstellar distances: radio transmitters, lasers and artificial transits. The quantitative comparison is based on physical quantities depending on energy cost and transmitting time L, the last parameter in the Drake equation. With our assumptions, radio transmitters are the most energy-effective, while macro-engineered planetary-sized objects producing artificial transits seem effective on the long term to transmit an attention-getting signal for a time that might be much longer than the lifetime of the civilization that produced the artifact.