Scientific theories need reconstruction every now and then. If they didn't need reconstruction they would be facts, not theories. The more facts we know, the less radical become the changes in our theories. Hence they are becoming more and more constant. But take the theory of gravitation; it has not been changed in four hundred years.

Take the rose—most people think it very beautiful: I don’t care for It at all. I prefer the cactus, for the simple reason that it has a more interesting personality. It has wonderfully adapted itself to its surroundings! It is the best illustration of the theory of evolution in plant life.

[I predict] the electricity generated by water power is the only thing that is going to keep future generations from freezing. Now we use coal whenever we produce electric power by steam engine, but there will be a time when there'll be no more coal to use. That time is not in the very distant future. ... Oil is too insignificant in its available supply to come into much consideration.

No evidence or proof of the existence of a God has been found in the phenomena of nature, based on experience.

Marking dynamos for repair $10,000.00-2 hours labor $10.00; knowing where to mark $9,990.00.

Spiritual power is a force which history clearly teaches has been the greatest force in the development of men. Ye. we have been merely playing with it and never have really studied it as we have the physical forces. Some day people will learn that material things do not bring happiness, and are of little use in making people creative and powerful. Then the scientists of the world will turn their laboratories over to the study of spiritual forces which have hardly been scratched.

I have succeeded in getting my actual work down to thirty minutes a day. That leaves me eighteen hours for engineering.