The Exploration of the Moon [antikvár]

can IT is little more than fifty years since the flight of the first successful aeroplane. That fifty years has been the most momentous in the whole history of Mankind; it has seen changes in society, art, and politics beyond the wildest dreams of our grandfathers. But above all, it has been an age of astounding advances in science and technology— so much so that the material world around us is now being completely transformed every generation. As a result, we have now come to accept the idea of change—forgetting that for the greater part of history everyday life remained almost unaltered from one century to the next. Ours is the first age which accepts no frontiers, which does not admit that anything is impossible because it has never been done before. The change in outlook is profound, and perhaps may be summed up by the following example:—at the opening of this century, there was scarcely a single scientist who would admit the possibility of heavier-than-air flight. Today, on the other hand, it would be quite difficult to find any competent expert prepared to state outright that space-travel was impossible. As a result of this newly-awakened consciousness of the future, an enormous amount of study has been debted to the still infant science of "astronautics," and probably no achievement of the human mind has been so well documented before the event as has the conquest of space. Until recently, speculations concerning interplanetary flight were based almost entirely on theory; there were no practical achievements to support the claims put forward. In the last decade, however, the situation has been completely transformed by the development of giant rockets such as the V.2. In many parts of the world, thousands of men are working on rockets of ever-increasing speed and range. It is typical of our age that ninety per cent of this work is for military purposes. Nevertheless, whatever its motivation, it is providing the skills and knowledge which will give humanity the freedom of space. ' One result of this work is that the idea of rocket-flight in the empty vacuum beyond the atmosphere is universally accepted. Not so long ago, there were many people who held the totally erroneous idea that a rocket had to have "something to push against" and so could not work in space. This fallacy is now practically extinct, but it is still not generally realised that rockets actually work much better in a vacuum, where the escaping exhaust gases are no longer hindered by the presence of air. Although the rocket has many limitations, and presents great problems to engineers, metallurgists and chemists, there is now no question of its ability to conquer space. The heights reached by present-