Question for @naval: I know you're a big physics guy. In a sense, all physical interaction in nature is a transaction record. When one ball collides into another, it passes its kinetic energy, not unlike sending money to someone else.
The balls do not pass this information on to a distant planet. It's stored locally, until it is needed. Said another way, unless one of those balls gets close to something else, the change in kinetic energy is ignored. Why shouldn't the blockchain work the same way?