where's the 10 foot piece of Chalk that he used?
You mean 20 foot piece! Writing with a piece of chalk that size would be just as impressive as the size of the blackboard itself.
My guess would be there is a sliding ladder off to the side but I don't know for sure as I've never been in a classroom like that. What schools have blackboard like that? MIT?
The professor would probably know how it's done.
