Professor Kaos exclaims truimphantly that he has the ‘most popular show in the Fringe!’ and with good cause. The large room at the Counting House is full to bursting, with children and adults sitting on the floor, tables, windowsills, and many more standing. I spent the hour sitting on a plant pot. Clearly something is pulling the lunchtime masses to science, and in true Free Fringe spirit no-one was turned away.The energetic Professor Kaos bounds cheerfully through simple but effective ‘experiments’ – mostly neat tricks that make parents gasp and kids squeal. He holds a flame to a water balloon above the head of a volunteer boy, then explain why he didn’t get wet. He demonstrates the power of an Airzooka by liberally shooting what they accurately describe as a ‘fist of spinning air’ into the crowd. The showy finale is just what it says on the tin - showy. All audience members are forced to take an oath to not try it at home and then... well, you’ll just have to go and see for yourself. This show works because of the easy rapport Professor Kaos has with the audience. It is a bit disjointed from one experiment to another, with no particular story line or overarching message, but constant jovial repetition to drive points like ‘gravity!’ and ‘air pressure!’ home make it feel like we’re all doing real science. Laughs are cheaply bought – what could be funnier than spraying your dad in the face with water? – but nevertheless effective.This was certainly not a well crafted double act, assistant Dangerous Dave more of a clumsy distraction than an addition to the comedic staging, but little can detract from Prof. K’s impeccable showmanship.