Hard boiled eggs

      I noticed  many cracked eggs when I boiled them.   Being a Science teacher, I recalled some principles. Like a balloon, when exposed to heat, it explodes when the heat temperature reaches its maximum. The hot lava, ashes of a volcano will also find its way to the crater once it explode. So , I decided to prick the egg with a needle on the round part of it so that when  the egg heats up, it would not crack. The hot water content will go up to the small hole opening.