Authors: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

Curiously, a principle affects your life whether you are aware of it or not. For instance, the principle of gravity was working long before the apple ever fell on Newton's head. But once it did, and he understood it, then we as a society were free to harness this principle to create, among other things, airline flight.

Andy Andrews