> Blockchains are irrevocable and unalterable But so are events in the real world. When you think about "reversing or changing a transaction" what you really m

> Blockchains are irrevocable and unalterable But so are events in the real world. When you think about "reversing or changing a transaction" what you really mean is creating a new transaction that brings an equivalent amount back to the person that paid it. This is done in the real world by knowing the identity of the receiver person or entity and threatening them with consequences if the money is not returned. It seems to me more a problem of being able to identify the parties in a transaction rather than of mutability of the ledger.