Bitcoin Forum

https://twitter.com/BitMEXResearch/status/1310886330239455233
Bitcoin had a stale block this morning, at height 650,491. No double spends have been detected

https://forkmonitor.info/stale/btc/650491
There was also an earlier stale block today:

* Height 650,473
* Hash 0000000000000000000dba80455fcb5a8f9716375845f295dd755edb29e32fd8

Our systems failed to detect this

Once again there were no double spends

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What Are Stale Blocks?
Stale Blocks are blocks that are no longer part of the current best blockchain because they were overridden by a longer chain.

https://medium.com/@cryptobolts/what-are-stale-blocks-simply-explained-b445682274c6

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It's just amazing how it proves Bitcoin's resilience. In a possible blackout in the communication between poles of the planet, we could still easily identify the longest chain and continue without major consequences.

A btc transaction could be good to have more than once confirmation so that it will not get over ride to it.  I just read that the number of confirmation will affect the depth of the transaction in a blockchain where it could not be replaced or removed. But having 1 confirmation for btc transaction is enough to conclude the success of bitcoin transaction. Still I need to read more info about transactions of bitcoin and I can be wrong also in what I had been stating here. I will need some users to clarify on this matter. Hopefully I can read a reply.

It's also something that potentially would slow down some operations depending on where payment servers are located. For example if some trans Atlantic cables were severed, could bitcoins data still be carried across by Internet satellites or will EurAfAsia have one chain and America have the other? Potentially extremely unlikely but if a country like China shut itself off there could be a problem with quite a few exchanges (I don't know how the % of China to Canada to the nordics makes up if they're even still the "mining powerhouses" they once were)...

Correction: It would be the chain with the most work involved in creating it, which is not necessarily the longest chain. In your hypothetical scenario of a chain split, both chains would end up with less total hashrate and so would adjust their difficulty downwards to compensate. A chain with less hashrate could generate more blocks, but the shorter chain with fewer but "harder" blocks may have done more total work, and so would be the favored chain.

No, it isn't, exactly as we have just seen here. With stale blocks, a transaction can go from 1 confirmation back to zero confirmations if the block it is included in ends up being rejected in favor of a different block.

not always. the two miner nodes are working on pretty much the same mempool and with similar preferences. so they most probably end up with blocks that are more than 90% similar. there is a good chance that a transaction in stale block is also confirmed in the other block that replaced it.

i'm curious to know what was the difference in time between these two blocks though? and which one came first (the stale block or the other)?

Are you sure? I mean, in a scenario like what happened. Where everything is working in a normal way. Suddenly, there is an error in the structure of the internet and we have for a moment two separate poles. In less than 1 hour, would it be possible for a chain to have more blocks with a smaller hashrate?

I believe that the block exactly after this blackout would define it. Or not?

If it was only an hour then tbh it would be the longest chain.

The longest chain would be made up of the luck% x power so it might not be the one with the highest hash power if "luck" favoured the other chain (eg a block on one of the chains hashed in a few seconds to be below the target).

Even if it was at the difficulty change when it split, the split would be based on the mean average of the last 2016 blocks so would result in a very similar difficulty for both chains (potentially enough for the new hashes to be under the new target even on the longest chain with the slightly higher difficulty) besides that, I don't know the rest of the consensus rules on determining which nonce is actually favoured.

Interesting, I missed this news

Yes. As jackg has said, after only an hour then the chain with the most work would also be the longest chain. There would need to be a chain split which lasted for a week or more, including over a difficulty adjustment, to create a chain with more blocks but less difficulty.

This is different issue, and yes, this is also possible. We see block times of over an hour not infrequently. Let's say there is a chain split right now which lasts an hour. The hashrate is split 60%/40%. It is entirely possible that the part with 60%, through random chance, only finds a single block in the next hour, while the part with 40% could find two or more. When the chains recombine, the chain with the smaller hashrate during the split will become the main chain.

https://forkmonitor.info/stale/btc/656477

"Bitcoin appears to have a stale chain of length 2, quite a rare event" https://twitter.com/BitMEXResearch/status/1326627907805065218?s=20

It happened again, but this time the event was even more rare. Nothing that causes a problem, just a curiosity.