Back in time to 100 BC, what knowledge would you impart to the people?
Xichekolas: Your question made me think of this:http://www.qwantz.com/fanart/timetravelling.jpgAll useful information, but you have a point about the receptivity of the world in 100BCE. If you start talking about germs spreading disease, people are going to assume you are talking about demons and are possessed.I'd probably try to find some leading scientific minds of the day (Jing Fang, Marcus Pollio, or the people that created this: http://en.wikipedia.org/wiki/Antikythera_mechanism) and work with them to 'discover' new ideas. They would probably be eager to learn, and could take your ideas and put them in the context of the age. Of course, you'd have to learn some ancient Greek and Chinese first. ;)