Remember when, as a kid, you would pass “top-secret” notes written in lemon juice that your friends could only read in the right light? Well, in light of new nanotechnology research, this now sounds absurdly antiquated, like cave painting in the modern era. Instead, the youth of the future (and adults, too) could have the option to communicate via documents that self-erase at a programmed time. picked by AutumnLotus 5 months ago