I have adapted one of my bigger demos – the hi-striker – so that it shows the difference that mass can have when you try to act against gravity. I wanted to see what it looked like, so have taken a short film which you can watch below. I’m a bit nervous at the start because I was trying to pop the first balloon (there were sparkly things inside!) and I don’t like loud noises, but it didn’t quite work. I would say I’ve fixed it now :-) Although from this evidence I’d be no use as an Astronaut as the loud bang from the rocket would scare…