There is nothing in between blocks of time inside the ledger or between addresses in keyspace. There are only quantized boundaries separating one from another. That’s why we correlated the speed of information in bitcoin and the speed of light in the universe as identical interpretations of the same substrate in their respective ledgers, one perspective is interior and physical (ontological), the other is exterior and informational (epistemological). Planck Time and Length are real, but they are the propagation/update rule of blocks experienced within. There are only singular blocks of time, everything else is a derivative of those blocks in fluid motion. Hence the relationship of time and distance and time and memory. A true mirror. Obviously outside of Bitcoins ledger the are a vast number of Planck blocks that exist between each bitcoin block (stochastic), but that’s only because of where we exist as observers. We simply can never see the time between Planck blocks from within if the universe is embedded in another timechain. By architecture of Bitcoin, we can only deduce its necessity of time existing within time until you reach the genesis of all chains. I’m not sure what you mean by eternity. A discrete process that is infinite in run? I think we can grasp what we cannot compute since all thoughts are manifested from the higher order structure extratemporally to this ledger, which id argue we are only here because they too have Bitcoin to write our chain. Modernity loves simulation theory; how about a computation instantiation from the only computer network that can produce non-biased irreversible time, a p2p electronic cash system.