Only Realistic Flight Schedules Should Be Proposed,

There Are Theoretical Physicists Who Imagine, Deduce, And Guess At New Laws, But Do Not Experiment; And Then There Are Experimental Physicists Who Experiment, Imagine, Deduce, And Guess.

Nature...cannot Be Fooled!

Looking Back At The Worst Times, It Always Seems That They Were Times In Which There Were People Who Believed With Absolute Faith And Absolute Dogmatism In Something. And They Were So Serious In This Matter That They Insisted That The Rest Of The World Agree With Them. And Then They Would Do Things That Were Directly Inconsistent With Their Own Beliefs In Order To Maintain That What They Said Was True.

A Scientist Is Never Certain. ... We Absolutely Must Leave Room For Doubt Or There Is No Progress And There Is No Learning.

When A Scientist Doesn't Know The Answer To A Problem, He Is Ignorant. When He Has A Hunch As To What The Result Is, He Is Uncertain. And When He Is Pretty Darn Sure Of What The Result Is Going To Be, He Is Still In Some Doubt. We Have Found It Of Paramount Importance That In Order To Progress We Must Recognize Our Ignorance And Leave Room For Doubt. Scientific Knowledge Is A Body Of Statements Of Varying Degrees Of Certainty - Some Most Unsure, Some Nearly Sure, But None Absolutely Certain.