The year 2100 will see eugenics universally established. In past ages, the law governing the survival of the fittest roughly weeded out the less desirable strains. Then man's new sense of pity began to interfere with the ruthless workings of nature. As a result, we continue to keep alive and to breed the unfit.

With ideas it is like with dizzy heights you climb: At first they cause you discomfort and you are anxious to get down, distrustful of your own powers; but soon the remoteness of the turmoil of life and the inspiring influence of the altitude calm your blood; your step gets firm and sure and you begin to look -- for dizzier heights.

Every living being is an engine geared to the wheel-work of the universe.

As in nature, all is ebb and tide, all is wave motion, so it seems that in all branches of industry, alternating currents -- electric wave motion -- will have the sway.

The spread of civilisation may be likened to a fire; first, a feeble spark, next a flickering flame, then a mighty blaze, ever increasing in speed and power.

In the twenty-first century, the robot will take the place which slave labor occupied in ancient civilization.

Though we may never be able to comprehend human life, we know certainly that it is a movement, of whatever nature it be. The existence of movement unavoidably implies a body which is being moved and a force which is moving it. Hence, wherever there is life, there is a mass moved by a force. All mass possesses inertia; all force tends to persist.

We should begin at the very root from which we spring, we should effect a radical reform in the character of the food.

My ear barely caught signals coming in regular succession which could not have been produced on earth.

To know each other we must reach beyond the sphere of our sense perceptions.

Our virtues and our failings are inseparable, like force and matter. When they separate, man is no more.

No free energy device will ever be allowed to reach the market.

Alternate currents, especially of high frequencies, pass with astonishing freedom through even slightly rarefied gases. The upper strata of the air are rarefied. To reach a number of miles out into space requires the overcoming of difficulties of a merely mechanical nature.

I am unwilling to accord to some small−minded and jealous individuals the satisfaction of having thwarted my efforts. These men are to me nothing more than microbes of a nasty disease. My project was retarded by laws of nature. The world was not prepared for it. It was too far ahead of time, but the same laws will prevail in the end and make it a triumphal success.

Inventors don't have time for married life.

The opinion of the world does not affect me. I have placed as the real values in my life what follows when I am dead.

The day science begins to study non-physical phenomena, it will make more progress in one decade than in all the previous centuries of its existence.

The harness of waterfalls is the most economical method known for drawing energy from the sun.

Each day we go to our work in the hope of discovering.

The individual is ephemeral, races and nations come and pass away, but man remains.