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 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.

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 ...