Primordial Black Holes as Heat Sources for Living Systems with Longest Possible Lifetimes

Just forty years ago, Hawking wrote his famous paper on primordial black holes (PBH). There have been since innumerable discussions on the consequences of the existence of such exotic objects and ramifications of their properties. Here we suggest that PBH's in an ever expanding universe (as implied by dark energy domination, especially of a cosmological constant) could be the ultimate repository for long lived living systems. PBH's having solar surface temperatures would last 10^32 years as a steady power source and should be considered in any discussion on exobiological life.