In the debate the other night, McCain said:

 “While we were working to eliminate these pork barrel earmarks he (Senator
Obama) voted for nearly $1 billion in pork barrel earmark projects. Including $3 million for
an overhead projector at a planetarium in Chicago, Illinois. My friends, do we need to spend
that kind of money?”

John, this is an overhead projector:

This is a planetarium projector:

(Carl Zeiss Planetarium)

This is science illiteracy at its worst.   McCain knew that the projector was for a planetarium and was clueless what a projector in a planetarium does.  I suppose he is mad that the Air Force is spending millions of dollars on video games.  Oh wait... those are flight simulators!

By the way... here's a PDF file of what Adler Planetarium had to say about McCain's statement.