Page:Popular Science Monthly Volume 91.djvu/851

 Breaking the Chain That Binds Us to Earth

��We might escape if we could be shot into space at a speed of seven miles a second

By Charles Nevers Holmes

��MAN is chained to his Earth, his planet-home. His chain is invisible, but the ball is always to be seen — the Earth itself. The chain itself" is ap- parently without weight, while the chain's ball weighs about 7,000,000,000,000,000,- 000,000 tons!

This ball or Earth acts like a huge magnet, drawing us towards it, and the force of this terrestrial attraction is popu- larly expressed in what we call our "weight." Everyone of us is, therefore, chained to the Earth by his "weight." Although the invisible chain permits us to roam almost anywhere upon the surface of our planet- home, it ties us to this terrestrial home, and we can no more leave our Earth than we can fly through its atmosphere without artificial wings.

It is true that man, assisted by the lifting power of certain gases or machinery, may rise in a balloon or airplane thousands of feet above his Earth's surface, and reach a level where he can not breathe with com- fort. His terrestrial chain can be stretched somewhat, so to speak, but there is a limit to this stretching. The chain is still there, although he may not feel it, and for a short while may forget its existence. Despite twentieth century science and invention, man has not yet broken his terrestrial fetters. He may escape several miles above the floor of his planet-home, but sooner or later he has to return to that floor, some- times more speedily than is safe for him. Yet man might escape wholly from his world, forever, and the time may come when he can leave the earth just when he pleases. All that ^ealfsSn)

26,000 Feet per second partly breaks chain

��is necessary is velocity — velocity greater than that of modern war-projectiles, swift as they seem to be. Such war-projectiles possess a muzzle-velocity of from two to three thousand feet per second, and after a comparatively short flight the invisible chain pulls them down to the ground. But were these projectiles to travel at a far higher speed, say about 26,000 feet per second, they would never fall to the earth's surface, unless interfered with, but would travel forever around and around our world. That is, the terrestrial attraction would be just balanced by the velocity of the projectiles.

If this speed were further increased, if a projectile were given a velocity of 37,000 feet, or approximately seven miles a second, it would then leave the earth and never in all probability be seen again. And if a man were enclosed in this projectile hi would, of course, escape from his planet- home. So that any one of us may depart our world if only an air-ship is invented that can be shot from the terrestrial surface with an initial velocity of 37,000 feet per second. Any one embarking on such an air- ship would very quickly break the chain attaching him to this earth. But although he would be able to leave this world, in all probability he would not be able to return. And a permanent exile from this planet, roving around in space, might re- ceive a very cold reception at the surface of the Moon or a very hot one at the surface of the Sun. However firmly the wander- lust might be fixed upon him, he would doubtless find himself longing to get back home and devising means to get back again

into the old environment and under the old conditions.

���All that is necessary to enable man to escape from his planet home is velocity — velocity greater than that of war projectiles and great enough to balance the terrestrial attraction

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