What if we could travel not just through space, but through time itself? If you could travel through time, would you change the past or the future? What if you found it couldn't be changed? What price does the time traveller and the people they are closest to pay? This is a journey from H. G. Wells The Time Machine through ideas like The Grandfather Paradox and The Butterfly Effect to the professional time traveller that is the ever popular Doctor Who. Steven Moffat, David Tennant, Karen Gillan, and Neil Gaiman offer a unique perspective on the Doctor. Edward James Olmos reveals the hidden meaning of the language he created for the vision of the future that is Blade Runner. Bob Gale and Christopher Lloyd take us behind the scenes of Back to the Future, while Ed Solomon describes the joy of solving a time travel conundrum for Bill & Ted's Excellent Adventure. But what would be the physical…