Robert W. Mellette
The history of space flight is full of dreams, heroism, triumphs and tragedy. Long before man would actually travel in space he journeyed there in his mind. A Greek myth tells of Icarus flying too close to the Sun, melting his waxen wings. Persian legends speak of flying magic carpets and bird-drawn flying chariots. In more modern times, the American authors Jules Verne and his younger contemporary, H. G. Wells wrote fantastic science fiction stories that would become fact only a century later.
One of Jules Verne’s most prophetic writings, From the
Earth to the Moon
, was first published in 1865. His books owed their popularity to their peculiar combination of fantastic detail and plausible scientific explanation. His most grievous error was his choice of a propulsion system. In his book, the space travelers are carried aloft in a velvet upholstered aluminum capsule shot from a giant cannon buried in the earth in Florida. This type propulsion system works in the circus, but surely would be fatal for moon voyagers!
The important contribution that writers like Jules Verne and others made to space flight, was that they sowed seeds in the form of ideas that would be harvested by a new breed of more practical dreamers. Two young impressionable readers of Verne’s works were the Russian schoolmaster, Konstantin Tsiolkovsky and a shy American physics professor, Dr. Robert H. Goddard. Together, in widely separated parts of the world, these great visionaries began to seriously explore the feasibility of using rocket power to overcome the chains of gravity that had held man on the earth for all of recorded history.
Ardous Huxley once said that “‘there is no more powerful force than an idea whose time has come.”’ The time had come for one of the most important ideas in human history. The rocket, more specifically the liquid fueled rocket, could provide mankind with the means to escape from the planet Earth-to begin the exploration of the universe. The Russian Tsiolkovsky was content to work in the abstract, but Goddard, the more practical of the two, wanted to put his theories into practice, much to the displeasure of his Massachusetts neighbors.
The work of the early space pioneers built on the genius of others. Sir Isaac Newton is quoted as having said, “‘that if he had seen further than others, it was because he was standing upon the shoulders of giants that had come before him”. Now Tsiolkovsky and Goddard would stand upon Newton’s shoulders and look far, far into the future. By the time Goddard and Tsiolkovsky began their rocket experiments, nearly two decades had elapsed since Sir Isaac Newton had published his classic work
Philosophiae
Naturalis Principia Mathematicia
, or “‘Mathematical Principles of Natural Philosophy”’. One of the main ideas discussed in this work was Newton’s Third Law of Motion. This law states: To every action there is always opposed an equal reaction; or, the mutual actions of two bodies upon each other are always equal but opposite in direction. It should be noted that at the time Newton stated this law, he had guns in mind, not rockets, but the principle remains the same. This law, although simple and direct, is often misunderstood by both students and adults alike. A common misconception is that a rocket pushes against air molecules. The fallacy of this idea becomes apparent when the learner is reminded of the fact that no air molecules exist in outer space. In fact, Robert Goddard conducted experiments in a vacuum chamber that proved that reaction engines like the rocket are actually more efficient in the vacuum of space. I believe that children learn best through direct evidence. In keeping with this philosophy there are many ways to have children investigate the law of action-reaction. Several examples of this principle can be drawn from their everyday experience. What happens when they jump off a skateboard? When you dive off a raft, which way does the raft tend to move? Several experiments with simple reaction engines are included in the sample lesson plans.
