Is it possible to make ice with neutral buoyancy, so that if you placed it halfway down a glass of water and released it, it would remain there and not float to the top or sink? B, Kent, England
Not without using something other than pure, normal water for the ice. The density of ice is always less than that of water at the same pressure. While squeezing the ice will increase its density, it will also increase the density of the water so the ice will always float. Of course, you could add dense materials to the ice to weight it down to neutral buoyancy, but then it wouldn’t be pure ice any more.