Vintage Sci-fi. In its day (1950s) it was truly a work of imagination. If you can forget your in 2007 and imagine your in 1950s you'll enjoy this book.
This is another of Heinlein's "Future History" books with a series of short stories that fit into it. These include: "Let There Be Light:,"The Roads Must Roll","The Man Who Sold the Moon", and "Requiem."
