Tritium as an Anthropic Probe

TL;DR

This paper explores how a slight change in tritium's mass could significantly alter stellar evolution and potentially impact the conditions for life, linking fundamental physics to astrobiology.

Contribution

It proposes that small variations in tritium mass could dramatically extend stellar burning phases, affecting planetary formation and the emergence of intelligent life.

Findings

Deuterium+tritium burning could last 4-8 times longer than deuterium burning.

The mass difference of tritium is finely tuned within a few percent of neutron-proton mass difference.

A power-law distribution of physical constants may be necessary to explain fine-tuning.

Abstract

I show that if tritium were just 20 keV lighter relative to helium-3, then the current deuterium burning phase of pre-main-sequence stellar evolution would be replaced by deuterium+tritium burning. This phase would take place at the same temperature but would last a minimum of 4 times longer and a maximum of 8 times longer than deuterium burning and so would yield total energies comparable to the binding energy of solar-type pre-main-sequence stars. Hence, it could in principle radically affect the proto-planetary disk, which forms at the same epoch. I suggest that this may be one of the most "finely-tuned" parameters required for intelligent life, with the mass range only a few percent of the neutron-proton mass difference, and 10^{-5} of their masses. I suggest that the lower limit of this range is set by the physics of disk formation and the upper limit by the statistical properties of fundamental physics. However, if this latter suggestion is correct, the statistical distribution of physical "constants" must be a power-law rather than an exponential. I also suggest a deep connection between fundamental physics and the search for extrasolar life/intelligence.