Life and Mind
摘要
The physical world maintains its order and balance through physical symmetries. These symmetries are invariant laws that hold in all places and at all times. Even as the universe is in constant change, the symmetries of physical law ensure continuity in the transitions. As the acids in my stomach break down the proteins of my dinner last night, the chemical reactions that take place are balanced. Nothing is created or destroyed. The number of atoms and the elements involved on one side of the reaction are the same in number and type once the reaction has taken place.