[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.

As for my memory, I have a particularly good one. I never keep any record of my investigations or experiments. My memory files all these things away conveniently and reliably. I should say, though, that I didn’t cumber it up with a lot of useless matter.

The scientist is not much given to talking of the riddle of the universe. "Riddle" is not a scientific term. The conception of a riddle is "something which can he solved." And hence the scientist does not use that popular phrase. We don't know the why of anything. On that matter we are no further advanced than was the cavedweller. The scientist is contented if he can contribute something toward the knowledge of what is and how it is.

[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.

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

From a mathematical standpoint it is possible to have infinite space. In a mathematical sense space is manifoldness, or combinations of numbers. Physical space is known as the 3-dimension system. There is the 4-dimension system, the 10-dimension system.

The most important advance in the next fifty years will be in the realm of the spiritual - dealing with the spirit of thought.