The root cause of the looming energy problem - and the key to easing environmental, economic and religious tensions while improving public health - is to address the unending, and unequal, growth of the human population. And the one proven way to reduce fertility rates is to empower young women by educating them.

Symmetry does mean something different for physicists than for members of the public. It means that an object or a theory does not change when you make some transformation - either rotating or moving it or doing something to the equations.

The biggest conceptual change over the last 100 years in the way physicists think about the world is symmetry.

Lawrence M. Krauss Quotes