Full Disk Images of Earth from GOES-17
This kind of thing could replace some uses of blockchain. The pattern of clouds on earth every day is unique, so anything that needs a timestamp with 1-day resolution could just tie it to a hash of today's cloud image pixels gathered from many receivers around the world, each taken at noon from the POV of a given geostationary satellite. That way one could prove that an event took place no earlier than today, especially if you hash each cloud photo with the hash of the one from the day before, which creates a cloudchain. The chain's ordering is verifiable from multiple sources and created wholly external from any human agency or pseudo-random number generator.Speaking of which, you could also use the pixels (or some permutation of them) as a random number seed that changed every day.