Three cones can fit inside a cylinder of the same diameter and height. Remember the volume of a cylinder is \(\pi r^2 h\). The volume of the cone is one third of the volume of the cylinder.

Three cones have the same volume as one cylinder of the same diameter and height. Remember the volume of a cylinder is \(\pi r^2 h\). The volume of the cone is one third of the volume of the cylinder.

Dirac cones were first observed in 2008-2009 using angle-resolved photoemission spectroscopy (ARPES) on the potassium-graphite intercalation compound KC8 and several bismuth-based alloys. As a ...