Jim talks with Matthew Pirkowski about the kinds of consensus mechanisms that can be used to secure blockchains. They discuss active inference, proof of work vs proof of stake & the relationship between them, auto-catalytic networks, proof of work in emergent nature, what consensus means & why it needs to be protected, integrity of the ledger, an analogy with clocks, accelerating entropy, photosynthesis, exploring vs exploiting tensions in emergent systems, coordinating central points of reference, energetic openness, the relationship between energy & information, resistance to manipulation, postmodernity & symbols untethered to reality, the evolution of evolvability, adaptive drift, a stable foundation for building infrastructure, the tight relationship between information theory & thermodynamics, whether existing cryptocurrencies exist in a Goldilocks zone vs an arbitrary spot in design space, bugs of global reserve currencies, whether investing in Bitcoin is an anti-social act, currency vs wealth, personal stores of abstract potential energy, and much more.