I've written about this topic in the past previously here, but there is only so much than can be condensed in a single reddit post. To fully flesh out the physics of Bitcoin in a Type I, II, and III civilization required me to create some new models for Bitcoin mining and usage. I've gone ahead and organized my thoughts inside this paper.

Abstract:

This paper explores the feasibility of Bitcoin mining and usage as humanity advances through the Kardashev Scale, from a planetary (Type I) to a stellar (Type II) and ultimately a galactic (Type III) civilization. We analyze how Bitcoin and its Proof-of-Work (PoW) consensus mechanism can adapt to vastly different energy capacities, and interstellar-spanning distances. This paper proposes ideas such as new necessary mathematical models for hashrate efficiency, relative hashrate, and a Mining Feasibility Index to provide a framework for assessing mining viability across interplanetary and interstellar distances. Additionally, we propose the use of Federated Proof-of-Work sidechains and localized second-layer networks to enable scalable and secure usage of Bitcoin across stellar and galactic distances, even in the presence of relativistic travel and causality constraints. This work outlines a long-term vision for how Bitcoin could remain viable in a high-energy, space-faring future.