What would happen if gravity was twice as strong? Or if there was no friction in the world? Or if you brake suddenly with a nodding dog in the back of your car? This new series, hosted by Dr Marty Jopson, seeks the answers to these questions and more. With inventor Jem Stansfield and leading academics, find out what happens when a watermelon is blasted with artificial lightning and meet the female British ballistics expert Nikki Woolmore who finds out if a camera could stop a bullet. Plus, discover what would happen if you replied to all of the spam emails in your inbox.