In response to feedback from our awesome subscribers we asked Matt Parker to give us his guide to imperial measurements! Is an inch really an inch or is it three barleycorns? So a 6 inch ruler is actually 18 barley corns! Now where is that bag of barley... For Matt's video on the difference between metric and imperial paper sizes check out his video here: https://www.youtube.com/watch?v=mHeo62B0d0E Does your time disappear every time you check out YouTube? Why not stay an extra few minutes and watch James' video on what exactly is one second: http://www.youtube.com/watch?v=NXRVtfCpLr4&list=PLMrtJn-MOYmdWAOMg3ZlWzz2SDbeakx6I&index=2 http://www.youtube.com/user/HeadsqueezeTV http://www.youtube.com/subscription_center?add_user=HeadsqueezeTV