<HTML>Understood.
Let's say I go to a foreign planet. I, for whatever reason, wish to interface with the locals. I teach them some cool stuff (or I leave behind very important knowledge encoded into a physical structure). Will I leave my tools behind? My calculator? My sketches? Probably not.
Let's say I want to interface with people on a foreign planet but do not wish to do it face-to-face. What options do I have? Science and Math. What's the best way to communicate knowledge but not "frighten" this lesser-intellectual planet's people. Leave a structure behind that they can't prove did NOT come from a lost culture.
JL</HTML>
