It seems weekend mornings are time for me to think about esoteric things. This morning it was stealth planes. What makes them invisible to radar? That lead me to a really cool site called How Stuff Works.
Sure enough a search brought up an article on how the stealth bomber works.
Basically it doesn’t have flat surfaces, and is covered with a radio wave absorbing paint. Also all of the metal parts are inside the composite body of the plane. Doesn’t say what the radar absorbing paint is made of, only that it is very expensive and has to be reapplies all of the time.
A further look produced this company, which makes radar absorbing materials for the end user. Looks like you could build your own stealth plane if you wanted. Maybe I should get it for my car and see if I can avoid getting tickets.