Reports on experiments conducted on two biological clocks, in organisms in the plant and animal kingdoms, which indicate that biological oscillation can be arrested by a single stimulus of a definite strength delivered at the proper time. (GS)

Discusses four periods of development in American physics during the last two hundred years and the discoveries and research of both Benjamin Franklin and Henry Rowland. (MLH)

Discusses how sophisticated instrumentation techniques yield practical results in three typical materials problems: fracture analysis, joining, and compatibility. Describes techniques such as scanning and transmission electron microscopy, and Auger spectroscopy. (MLH)

Describes how the use of tunable lasers in coherent Raman techniques allows spectra to be taken for samples in which spontaneous Raman scattering is intrinsically weak. (MLH)

Discusses a new branch of optical spectroscopy that deals with the optical analogs of spin transients and provides ways to explore dynamic interactions in optically excited materials. (MLH)

Lists activities of the February 2-5, 1976, joint meeting of The American Physical Society (APS) and the American Association of Physics Teachers (AAPT) in New York city. (CP)

Reveals the self-imposed censorship practiced by western scientists to keep sensitive information concerning nuclear fusion from Nazi Germany before and during World War II. (CP)

Discusses recent progress in using tunable lasers to selectively separate substances at the atomic and molecular level. Emphasizes biological applications, such as selective excitation and breaking of hydrogen bonds in DNA. (MLH)

Discusses new laser techniques that make it possible to see optical spectra without Doppler broadening, to label energy levels, and to enhance sensitivity. (MLH)

Discusses the origin of de Broglie's concept and its influences on his contemporaries, notably on Einstein, Schrodinger, Elsasser, Davisson, and Thomson. Indicates that the theory served not only as the starting point of quantum mechanics, but also opened new experimental possibilities. Historical inaccuracies are corrected with new material…