This should put to rest once and for all the notion of many, including some self-styled scientists, that the explosion of a hydrogen bomb would set the hydrogen in the waters, and the oxygen and the nitrogen in the air, on fire and thus blow up the earth. The energy in common hydrogen is locked up in one of those cosmic vaults which only the sun and the stars that shine can open and which no number of H-bombs could blow apart. Oxygen and nitrogen are locked even for the sun. As for the deuterium in the water, it cannot catch fire unless it is highly concentrated, condensed to its liquid form, and heated to a temperature of several hundred million degrees. Hence all this talk about blowing up the earth is pure moonshine. But while we know that we have reached the limit of what can be achieved either by fission or by fusion, that by no means justifies the conclusion that we have reached the ultimate in discovery and that fission and fusion are the only possible methods for tapping the energy locked up in matter. We must remember that fifty years ago we did not even suspect that nuclear energy existed and that until 1939 no one, including Dr. Einstein, believed that it would ever become possible to use it on a practical scale. We simply stumbled upon the phenomenon of fission, which in its turn opened the way to fusion. If science tells us anything at all, it tells us that nature is infinite and that the human mind, driven by insatiable curiosity and probing ever deeper into nature’s mysteries, will inevitably find ever greater treasures, treasures that are at present beyond the utmost stretches of the imagination—as far beyond fission and fusion as these are beyond man’s first discovery of how to make a fire by striking a spark with a laboriously made flint. The day may yet come, and past history makes it practically certain that it will come, when man will look upon the discovery of fission and fusion as we look today upon the crudest tools made by primitive man. A great measure of man’s progress has been the result of serendipity, the faculty of making discoveries, by chance or sagacity, of things not sought for. Many an adventure has led man to stumble upon something much better than he originally set out to find. Like Columbus, many an explorer into the realms of the unknown has set his sights on a shorter route to the spices of India only to stumble upon a new continent. Unlike Columbus, however, the explorers in the field of science, instead of being confined to this tiny little earth of ours, have the whole infinite universe as the domain of their adventures, and many a virgin continent, richer by far than any yet discovered, still awaits its Columbus.