DESPITE the fact that the University of Illinois campus is "centrally isolated" 1 more than 80 physicists (including the discoverer, Rudolf Mossbauer) from 23 university, government, and industrial laboratories in eight foreign countries and the United States converged on Allerton House, the University of Illinois conference retreat, on June 5. They came to report their most recent, unpublished experiments and to present and discuss their ideas for future research in the exciting field of recoilless gamma-ray absorption. 2

There are cycles in the history of scientific development just as there are in the affairs of men. To keep a Society such as The American Physical Society healthy and strong in the face of these changes, we must review our objectives periodically and adjust to the demands and needs of the present. In preparing this report on the State of Physics I sought to acquire some sense of the historical development of American physics by browsing through two famous addresses given by Henry Augustus Rowland, the founder and first president of our Society.

EACH new discovery of natural science broadens our knowledge and deepens our understanding of the physical universe; but at times these advances raise new and even more fundamental questions than those which they answer. Such was the case with the discovery and investigation of the radioactive process termed 'beta decay'. In this process an atomic nucleus spontaneously emits either a negative or positive electron, and in so doing it becomes a different element with the same mass number but with a nuclear charge different from that of the parent element by one electronic charge. As might be expected, intensive investigation of this interesting alchemy of Nature has shed much light on problems concerning the atomic nucleus. A new question arose at the beginning, however, when it was found that accompanying beta decay there was an unaccountable loss of energy from the decaying nucleus1, and that one could do nothing to the apparatus in which the decay occurred to trap this lost energy2. One possible explanation was that the conservation laws (upon which the entire structure of modern science is built) were not valid when applied to regions of subatomic dimensions. Another novel explanation, but one which would maintain the integrity of the conservation laws, was a proposal by Wolfgang Pauli in 1933 which hypothesized a new and fundamental particle3 to account for the loss of energy from the nucleus. This particle would be emitted by the nucleus simultaneously with the electron, would carry with it no electric charge, but would carry the missing energy and momentum escaping from the laboratory equipment without detection.