Authentic Science Fiction Monthly No. 50 — page 104: what you’re looking at

Machine-transcribed from the original scan — historical spelling and the odd misread are preserved.

AUTHENTIC SCIENCE FICTION fast enough to push a big enough weight of air back- wards quickly enough—why then we were able to fly through the air. In space, however, we shall have no earth or water to push away benind us in order to advance. In order that we may move forward we may have to have something to push backwards. We shall have to take it with us. That is what we mean by fuel load. Fuel implies burning. We have the habit of getting our _ power on Earth by using the available oxygen all around us to burn things, but in space there’ll be no burning as we understand it on Earth. The chemistry of rocket fuels is a story that is just beginning, but in space why bother to burn anything? The space- ship could be made to move in any direction if anyone aboard threw a stone from it in the opposite direction. But remember the velocity factor. The stone is much lighter than the ship and so the heavy ship will move very 103 slowly and the stone may even be unable to escape from the gravitational attraction of the ship, and, by returning to it, bring the vessel back to its original position. Take heavier stones so that when the stone is thrown the vessel moves more quickly? Not a very practical idea. Throw the stone more rapidly? Fire bullets from a gun? That is what a rocket does. The bullets are now very small indeed—molecules of gases— but they are discharged at high velocity. And from what kind of gun do you fire a molecule? You don’t. You merély make it hot. A hot molecule is a molecule in rapid movement. That’s what we mean by heat. We are so used to burning things to make heat that we are ready to call any chemical reaction which produces heat a form of burning. Rocket propulsion then, depends upon heat-producing chemical re- actions which send a stream of fast moving molecules backward to send the rocket comiclbooks.corn