I've been reading Eric Voskuil’s Cryptoeconomics, and the mining proximity advantage (mentioned as a centralizing flaw in the book) got me thinking. Miners benefit from receiving new blocks sooner. Could that advantage be used deliberately to encourage separate, geographically local blockchains?

The Earth–Mars example (#534860) makes the latency problem obvious, but I wonder whether something similar could make sense here on Earth.

My motivation is pretty simple: I want to use money locally without having to validate everyone else’s transactions around the world. Each community could have an independent blockchain and its own coin, with atomic swaps between them. Bitcoin could still be what people save in and exchange through.

And it's clear that blockchains don't scale anyway, but communities don't either! So whereas larger blocks don't fix it, maybe separating chains does. And LN has a special place in my heart, but it's also clear that it won't be the way to scale either. So, we're left with different forms of custodial or trusted solutions, or multiple chains.

And communities will exist anyway, so it doesn't sound so stupid to split chains. If I travel somewhere, I acquire some of the local coin, spend it, and exchange whatever is left when I leave. You don't need to run a full node for that.

But boundaries shouldn't be imposed. Maybe one chain serves a large region initially, and smaller communities adopt their own chains when the cost of using and validating the existing one becomes too high. Whether those communities resemble countries, cities, or something else should depend on how people actually trade.

That raises a network science question: how local are payments when measured by number of transactions rather than monetary value? An enormous oil import might involve relatively few payments, while buying bread generates millions. Could we find communities containing 90% or 95% of their members’ payments? It looks like it: 98% of EEA-issued card-payments (by count, not volume) stay within the whole EEA.

I'm also curious about the Austrian economics angle. Different places have different prices and trading relationships. That doesn't automatically mean they need different money, but could cheaper local payments outweigh the advantages of a more widely accepted currency?

The hardest part seems to be mining security. Small chains using compatible hardware could be attacked by miners from a much larger chain. And a distant attacker building a private fork doesn't need to keep receiving local blocks.

So my questions are:

• Can proximity provide a useful mining or usage incentive?
• Could small independent chains protect themselves without permissioned miners or trusted location checks, while keeping SHA-256 mining?
• Would payment communities naturally sustain different coins, or would liquidity and monetary network effects pull everyone back toward a few?

Has this combination been explored? I'd be interested in both existing proposals and reasons it fundamentally falls apart.