Hydrostatics is the study of changing water pressure and it's relationship to water depth or column of water height in a pipe or tube In this video I'll demonstrate how water in a long thin tube can reduce pressure inside various soda bottles and can enough to crush them, actually it's atmospheric pressure that crushes them. Still, it's impressive when the reduction is due to the weight of just 2 cups of water. We'll also look at an alternative method for demonstrating the Magdeburg Hemispheres without using a vacuum pump, just a long thin plastic tube and 2 cups of water is all that's needed.