Indeed, in the Bitcoin source code and in more technical discussions, orphan blocks and stale blocks are two separate things: both are not part of the longest valid chain, but in an orphan block it is because the parent is unknown, whereas in a stale block it is because that part of the chain is known to no longer be longest. However, in. Based on block timestamps (which do not have to be accurate), the longest difference between successive blocks is seconds (5 days, 8 hours, 39 minutes, 20 seconds) between blocks 0 and 1. The second longest is seconds (1 day 1 hour 8 minutes 52 . The best chain consists of the longest series of transaction records from the genesis block to the current block or record. Orphaned records exist outside of the best chain. A bitcoin is defined by a sequence of digitally signed transactions that began with the bitcoin's creation, as a block reward.
Bitcoin longest blockBitcoin Block. All about cryptocurrency - BitcoinWiki
Imagine that the blockchain is blocks long and TWO miners both find valid blocks within a few seconds of each other and broadcast them to the network. You now have two chains, each of length Neither of these are longer than each other. Some bitcoind nodes will see the first miner's block and some bitcoind nodes will see the second. Temporarily you have two forks of the blockchain, each of length blocks long.
They are identical for blocks, but the st is different on the two forks. Sometime later another miner finds another valid block, the nd block, and that will be attached to exactly one of the forks.
This chain is now the longest at blocks and becomes the longest chain. It becomes the "definitive" blockchain. The transactions in the alternate fork don't disappear - they simply get put back into the pool of unconfirmed transactions and miners will put them into a subsequent block.
Sign up to join this community. The best answers are voted up and rise to the top. Ask Question. Asked 8 years, 1 month ago. Active 2 years, 8 months ago. Viewed 14k times. Active Oldest Votes. Pieter Wuille Pieter Wuille Sir, how a node selects the most recent block on the longest path; e. Is it just going compare their lengths number of blocks?
We look at the amount of work in each chain: the expected number of hashes that were necessary to build them. This loosely corresponds to the sum of the difficulties of the blocks in both chains which is almost always the same as just comparing the length, unless the fork spans a retarget. This answer doesn't precisely define "work". DairaHopwood helpful comment, although technically the comment right above yours does define it "expected number of hashes..
This is perfectly normal as the Bitcoin network is peer to peer and global. But is that one block that was on the chain awarded? The network chose the chain, and the transactions from the chain get recycled for the next block ? My understanding is that under most circumstances the transactions in each of the forks are mostly the same.
Any fee-paying transactions in the soon-to-be orphaned block eg B would likely be included in the block immediately following ie because those transactions are considered still available by miners working on their own fork A. They wouldn't need to wait for block , as the final paragraph implies. This excellent description cleared things up for me, thanks! My next question is: has it ever happened or recently happened that it happened twice in a row, thus there were 3 or four chains each of the same length and miners start working on each?