The Last Century of Physics

The mesotrons, or mesons, were the first elementary particles observed to be inherently unstable. This essay offers a reconstruction of the stream of researches related to mesotron decay, and examines how these researches shaped some of the basic concepts and practices of the emerging field of particle physics. Mass measurements could not settle the question of whether the mesons were a homogeneous kind of particles or an assortment of particles with different masses. The assumption of a single mass prevailed not on experimental grounds but because the mesons were identified tentatively with the carriers of the nuclear force according to a theory formulated by Hideki Yukawa. The identification gained currency because it entailed the prediction of meson decay, and thereby upheld the promise of a unified explanation of nuclear and cosmic-ray phenomena. In turn, the observation of decay and the measurement of the mean lifetime created the conditions for investigating the nuclear interactions of mesons at rest. Interest in these interactions was heightened, immediately after WWII, by the prospect of building and using accelerators to acquire knowledge about fundamental nuclear processes. Using decay to study nuclear capture, however, led to the realization that there exist not only different kinds of mesons but also two nuclear forces.     

The History of Chemistry: A Very Short Introduction

In 1668 Robert Hooke recognised the utility of a barometer which could foretell storms at sea, but neither he nor his contemporaries in Britain or elsewhere in Europe succeeded in constructing such an instrument which would work reliably on a moving ship. Theorists and instrument makers, including Hooke, Amontons, De Luc, Passement, Magellan and Blondeau proposed novel forms of tube, but at the time it was not possible to work glass to the suggested shape. The competition between France and England was won by Edward Nairne, who devised the constricted-tube barometer for Captain Cook's second voyage of 1772-75. Nairne barometers were soon taken on other British exploring voyages, but French ships were slow to follow the pattern, possibly in consequence of naval disruption following the Revolution. The earliest Nairne examples were adapted from the domestic barometer, with the tube mounted on a flat back, but within the lifetime of Nairne &; Blunt marine barometers adopted the form common for most of the nineteenth century, with the tube enclosed within a square or round-section wooden frame.     

单分子化学与物理

单分子科学的概念是在扫描探针显微镜、激光镊子和其他相关光谱法在纳米级或分子级研究中的应用中发展起来的。我们在此对近来单分子化学和物理的进展作一评论性的回顾,并主要介绍单分子化学和物理的概念以及单分子表面研究、单分子光谱检测、单原子和/蜮分子操纵、单分子荧光法、激光摄子、生物分子的力学研究,以及所谓单电子效应和单电子器件的进展情况。本文最后强调了单分子科学和技术的重要性。     

Orchid: A Cultural History

By now, the story of T. D. Lysenko's phantasmagoric career in the Soviet life sciences is widely familiar. While Lysenko's attempts to identify I. V. Michurin, the horticulturist, as the source of his own inductionist ideas about heredity are recognized as a gambit calculated to enhance his legitimacy, the real roots of those ideas are still shrouded in mystery. This paper suggests those roots may be found in a tradition in Russian biology that stretches back to the 1840s—a tradition inspired by the doctrines of Jean-Baptiste Lamarck and Etienne and Isidore Geoffroy Saint-Hilaire. The enthusiastic reception of those doctrines in Russia and of their practical application—acclimatization of exotic life forms—gave rise to the durable scientific preoccupation with transforming nature which now seems implicated in creating the context for Lysenko's successful bid to become an arbiter of the biological sciences.