Are Alien Civilizations Technologically Advanced?

TL;DR

This paper discusses the challenges in detecting advanced alien civilizations, emphasizing that direct exploration may be necessary to find relics or primitive signs, as remote observations might be insufficient.

Contribution

It highlights the limitations of remote sensing and advocates for planetary exploration to uncover signs of extraterrestrial technological civilizations.

Findings

Remote observations may not reveal advanced civilizations

Relics of destroyed civilizations could be detectable

Primitive civilizations might be indistinguishable remotely

Abstract

As we discover numerous habitable planets around other stars in the Milky Way galaxy, including the nearest star, Proxima Centauri, one cannot help but wonder why have we not detected evidence for an advanced alien civilization as of yet. The surfaces of other planets might show either relics of advanced civilizations that destroyed themselves by self-inflicted catastrophes or living civilizations that are technologically primitive. Such circumstances can only be revealed by visiting those planets and not by remote observations.