The simplest questions are often the best. Robert P Crease tries to answer one from a physics student in Kenya Seeking perfection Tennis balls are a low-cost way to explore simple physics concepts, ...

Materials Needed: a piece of flannel which is clean and dry or paper towel, stream of water, flexible plastic ruler and a party balloon. In order for the stream of water to flow out, you need to open ...

Materials Needed: superglue, PVC pipe, a piece of paneling, 2-3 tubes of glycerin of 100ml, smooth and transparent drinking glass and an empty transparent bottle clean and try with a screw on top. In ...