Message to 12,000 AD is a very interesting paper about keeping people out of a radioactive waste disposal site for the next 10,000 years. It\’s much more difficult than you\’d think, since the site must survive for 10,000 years and the message must be understandable in the future. The site also can\’t look like a monument or a place of worship, and the materials it\’s made of must be low value so they won\’t be stolen. Pretty cool reading.