There is a huge gulf between the real physics of space travel and the way it is commonly portrayed in movies and TV shows. That's not because space physics is difficult or obscure - most of the details were understood by the end of the 18th century - but because it can often be bafflingly counter-intuitive for a general audience. The purpose of this book isn't to criticize or debunk popular sci-fi depictions, which can be very entertaining, but...