The speed of light squared is a colossal number, illustrating just how much energy there is in even tiny amounts of matter. A common example of this is that 1 gram of water -- if its whole mass were converted into pure energy via E=mc² -- contains as much energy as 20,000 tons (18,143 metric tons) of TNT exploding.ow we're getting to the c² part of the equation, which serves the same purpose as the star-on and star-off machines in The Sneetches.. The c stands for the speed of light, a universal constant, so the whole equation breaks down to this: Energy is equal to matter multiplied by the speed of light squared.