A Physical Law Must Possess

I Consider That I Understand An Equation When I Can Predict The Properties Of Its Solutions, Without Actually Solving It.

Mathematics Is The Tool Specially Suited For Dealing With Abstract Concepts Of Any Kind And There Is No Limit To Its Power In This Field.

Hopes Are Always Accompanied By Fears, And, In Scientific Research, The Fears Are Liable To Become Dominant.

Well, In The First Place, It Leads To Great Anxiety As To Whether It's Going To Be Correct Or Not ... I Expect That's The Dominating Feeling. It Gets To Be Rather A Fever... At Age 60, When Asked About His Feelings On Discovering The Dirac Equation.

What Makes The Theory Of Relativity So Acceptable To Physicists In Spite Of Its Going Against The Principle Of Simplicity Is Its Great Mathematical Beauty. This Is A Quality Which Cannot Be Defined, Any More Than Beauty In Art Can Be Defined, But Which People Who Study Mathematics Usually Have No Difficulty In Appreciating.