Had one hoped to leave a time capsule for today’s Bostonians in the Permian period 250 million years ago, much less the Pliocene epoch four million years ago , they would have been completely, utterly screwed. This is also the case for anyone aspiring to send such an envoy into the geological deep future as well. Mindful of my eon-old local rock, and given a charge from Scientific American to figure out how far into the deep future one could possibly even hope to send a time capsule here on Earth, I stumbled upon the humbling work of Steve Holland of the University of Georgia.