The Limits to Blockchain Scalability

The "if you join the network" is contingent on the network still being active and widely used; presumably with the Ethereum Foundation or some successor also still being active. I may not've made that fully clear in the first paragraph.

If that were the case, you could ask the same question right now. And the answer is that they publish an official client you can download and should be able to trust. This would be the case in 2040 if the network is still active and the foundation still exists.

If the foundation is gone and the network is mostly dead, then it'd indeed be much harder or perhaps impossible. The second part of my answer covers that scenario:

>If no one uses it anymore or if it's so little-used that it's schismed into tons of other chains over the years, I think you can still probably obtain the original data you're looking for, but it'll take more effort to verify its authenticity.

>Especially if the data you're looking for occurred at a time when the network was healthy and intact (like 2020), all you need to do in 2040 is find a block number and corresponding root hash that existed in 2020. I think these'll likely be possible to find even if the network's dead, and you can compare them against several different sources to increase confidence that they're not fake. Then as you scour the internet and download different published blockchain copies, you can truncate it back to that block number and compare the hash.

>It's possible your search will be futile and you'll be unable to find a trustworthy record of block numbers and root hashes or that you'll be unable to find a verified 2020 blockchain, but I think your odds will be pretty good if the internet hasn't collapsed. Either way, as Vitalik pointed out, the odds are way higher you'll be able to find that compared to some data you entered into some SaaS in 2020.

Also majority in a decentral system is not that simple. It can be done with FBA (Federated Byzantine Agreement). If that's the case, then yes, account balances are simply agreed on and they call it a day (or technically its called a closed ledger). Then they add the next. Now ledger are blocks of data and the best way to order them is to chain them with hashes depending on the previous ledger (block). And we are back to "blockchain". Its still misleading the "magic" part isn't the chain of blocks. Its the fact that the double spending problem can be solves without an arbiter of truth.

>Just like WebMoney did circa 1998.

I dont know about the technical way this was implemented back then but most likely the system was operated by a single entity. There is some kind of master balance database and the all other sync with that. A double spending can be prevented by rules applies to the master DB. AKA a write-sync is denied if it violates the balance rules. This is easy to do centralizes and obviously who ever controls it can circumvent the rules if he wants to.

>[big purchases] of any big country could change and trigger the [purchase] for a lot of [buyers] of a country.

>Especially given BTC is used by Iran to bypass petrol restrictions, used by ransomware and all sort of dealers, as well as Chinese who want to flee.

[Didn't actually have to change this one, seems like buying pressure to me]

>Currencies are in theory regalian = only emitted by the central bank; [New world currency outside of central banks is the whole vision for crypto, so i don't see how this conflicts.]

>Once any country gets upset with this, they could blame terrorism on BTC and ask owners to prove their origin of wealth, which would be a major hurdle if the law was strict.[ Don't actually understand this one, how could you make me prove ownership of coins in a cold-wallet?]

Any of these mean anything to ya?