Money can be dirty fiat, heavy gold, or shiny Bitcoin, but what is it? The purpose of money is to transfer energy across time and space through physical or digital forms of communication. Lynn Alden's ledger theory of money is a good way to think about what money is.
Understanding blockchain from first principles can make the concept come alive. A blockchain is just a series of messages that are cryptographically hashed and linked together in sequence, which are placed in a publicly readable ledger. With Bitcoin, we can read and write to this public ledger. Bitcoin is digital speech.
