Odds are you’ve seen, heard of, or even been a part of a ‘human pyramid’, where a group of people form a pyramid by stacking one on top of another. It’s a common gymnastics exercise that’s been performed the world around, at circuses and festivals and even for the Guinness Book of World Records, where sixty-two people piled up underwater. The question is, how high can they go? There’s a physical limit, because eventually the strain on the bottom layer will be too great and the whole thing will collapse.
Fortunately, Hayley Allison from the University of Leicester in the UK has worked it all out with help from a group of fellow students, and I asked her just how high physics allowed human pyramids to rise.