Habitability on local, Galactic and cosmological scales

TL;DR

This paper explores the necessary conditions for life to emerge and develop across local planetary, Galactic, and cosmological scales, emphasizing the fine-tuned nature of these conditions and their interdependence.

Contribution

It introduces a comprehensive framework linking planetary, Galactic, and cosmological habitability conditions, highlighting their combined importance for life's emergence.

Findings

Habitability depends on conditions at multiple scales.

Galactic and cosmological constraints are crucial for planetary habitability.

Life's emergence may be due to fine-tuned cosmic and galactic factors.

Abstract

The aim of this paper is to underline conditions necessary for the emergence and development of life. They are placed at local planetary scale, at Galactic scale and within the cosmological evolution, as pointed out by the Anthropic Cosmological Principle. We will consider the circumstellar habitable zone (CHZ) for planetary systems and a Galactic Habitable Zone (GHZ) including also a set of strong cosmological constraints to allow life (cosmological habitability (COSH)). Some requirements are specific of a single scale and its related physical phenomena, while others are due to the conspired effects occurring at more than one scale. The scenario emerging from this analysis is that all the habitability conditions here detailed must at least be met. Then life asks something which may appear as "a monstrous sequence of accidents" as Hoyle (1959) thought, or as providential collaborations leading to realize how finely tuned is the architecture within which Life, as precious stone, is embedded.