So this is a situation similar to what happened with Ethereum when it split into Eth Classic and Eth? So in the case of segwit (with the transaction headers off chain in a separate database) the soft fork eventually becomes a hard fork... I'm having trouble visualizing how the transactions embedded in the blockchain (splitting the 3's from the 1's in the hashed strings) can be split off without violating the hashes against previous UTXO's. Will there simply be two competing histories and one that becomes worthless? If I could see it in code, I think this would make more sense to me. Not disputing that it can happen, just as it did in Ethereum, just don't understand the particulars of what commands they used on the blockchain to do it (for ETH/Classic).

Not familiar enough with how the segwit data being off chain could be used to spend. I read Mastering Bitcoin by Andreas Antonopoulos (well skimmed over it is more accurate) and understand the broadest level basics (elliptic curves and the immutability of the hashed blocks, merkle trees, bloom filters, etc). That book is also probably very dated by now.

Unless there are mitigating circumstances (c.f. below), lowest-cost proof-of-work mining requires electricity that is generated 24 hours a day, because electric storage is too expensive. So the economics of solar are very interesting because it can’t be a primary source for proof-of-work mining.

Solar orbital space mines? I think Blockstream now has satellites in orbit, not sure I like the idea of them mining in space (too centralized), but the cost of achieving earth orbit is astronomical (I know, bad pun).