PANews reported on July 20 that Vitalik Buterin responded to a question on the X platform about "What is a global universal blockchain" and said that the blockchain is a "truth machine". Specifically, it provides a consensus approximate truth about the time when a message was sent. It will not tell you "Is the moon landing true?" This greatly reduces the attack surface of the blockchain, but it does mean that we need other tools to actually perform (or more precisely, assist) the latter truth discovery.