It's a big question--is time travel possible? Being able to travel back in time to the age of the dinosaurs or forward to the megacities of the future would be incredible. Discover how theoretical physicists study whether this could ever actually be done and learn about . How telescopes observing distant stars and galaxies look into the past Why an astronaut returned to Earth younger than his identical twin brother What the link is between time and gravity . and so much more! Beautifully bound with stunning illustrations, this title is part of a unique and collectable series that will start a lifelong interest in science for kids. Each book in the series includes a QR code that links to The Big Questions Answered website for comprehensive free teacher resources and fun kids' pack.