Words Can Be Meaningless. If They Are

In Fact, The Science Of Thermodynamics Began With An Analysis, By The Great Engineer Sadi Carnot, Of The Problem Of How To Build The Best And Most Efficient Engine, And This Constitutes One Of The Few Famous Cases In Which Engineering Has Contributed To Fundamental Physical Theory. Another Example That Comes To Mind Is The More Recent Analysis Of Information Theory By Claude Shannon. These Two Analyses, Incidentally, Turn Out To Be Closely Related.

It Is Scientific Only To Say What Is More Likely And What Less Likely, And Not To Be Proving All The Time The Possible And Impossible.

We Are At The Very Beginning Of Time For The Human Race. It Is Not Unreasonable That We Grapple With Problems. But There Are Tens Of Thousands Of Years In The Future. Our Responsibility Is To Do What We Can, Learn What We Can, Improve The Solutions, And Pass Them On.

It Is The Facts That Matter, Not The Proofs. Physics Can Progress Without The Proofs, But We Can't Go On Without The Facts ... If The Facts Are Right, Then The Proofs Are A Matter Of Playing Around With The Algebra Correctly.

So Far As We Know, All The Fundamental Laws Of Physics, Like Newton's Equations, Are Reversible.