Amplified Piano

The introduction of electronic amplification to the piano, which began as an innocent bluff by a teenage composer living in the Arctic Circle, had a devastating consequence for Tudor’s virtuosity on the keyboard instrument: it dissolved his control of escapement mechanism, opening up instead the world of feedback where a sound once activated could potentially never end. A detailed examination of Tudor’s idiosyncratic realization of John Cage’s Variations II in 1962 shows what previous scholars, as well as the composer himself, have failed to see: the specific nature of the amplified piano that was altogether a different instrument from the piano. What the new instrument presented was not simply more complexity and indeterminacy but a specific kind of complexity and indeterminacy which is reflected in how Tudor actually performed the music.

Friction and Dynamics of Verge and Foliot: How the Invention of the Pendulum Made Clocks Much More Accurate

The tower clocks designed and built in Europe starting from the end of the 13th century employed the “verge and foliot escapement” mechanism. This mechanism provided a relatively low accuracy of time measurement. The introduction of the pendulum into the clock mechanism by Christiaan Huygens in 1658–1673 improved the accuracy by about 30 times. The improvement is attributed to the isochronicity of small linear vibrations of a mathematical pendulum. We develop a mathematical model of both mechanisms. Using scaling arguments, we show that the introduction of the pendulum resulted in accuracy improvement by approximately π/μ ≈ 30 times, where μ ≈ 0.1 is the coefficient of friction. Several historic clocks are discussed, as well as the implications of both mechanisms to the history of science and technology.

Thermodynamic impacts of combinatorial mutagenesis on protein conformational stability: precise, high-throughput measurement by Thermofluor

ABSTRACTThe D1 switch is a packing motif, broadly distributed in the proteome, that couples tryptophanyl-tRNA synthetase (TrpRS) domain movement to catalysis and specificity, thereby creating an escapement mechanism essential to free-energy transduction. The escapement mechanism arose from analysis of an extensive set of combinatorial mutations to this motif, which allowed us to relate mutant-induced changes quantitatively to both kinetic and computational parameters during catalysis. To further characterize the origins of this escapement mechanism in differential TrpRS conformational stabilities, we use high-throughput Thermofluor measurements for the 16 variants to extend analysis of the mutated residues to their impact on unliganded TrpRS stability. Aggregation of denatured proteins complicates thermodynamic interpretations of denaturation experiments. The free energy landscape of a liganded TrpRS complex, carried out for different purposes, closely matches the volume, helix content, and transition temperatures of Thermoflour and CD melting profiles. Regression analysis using the combinatorial design matrix accounts for >90% of the variance in Tms of both Thermofluor and CD melting profiles. We argue that the agreement of experimental melting temperatures with both computational free energy landscape and with Regression modeling means that experimental melting profiles can be used to analyze the thermodynamic impact of combinatorial mutations. Tertiary packing and aromatic stacking of Phenylalanine 37 exerts a dominant stabilizing effect on both native and molten globular states. The TrpRS Urzyme structure remains essentially intact at the highest temperatures explored by the simulations.

The potential which may lie in discarded, undeveloped or overlooked ideas

Purpose The purpose of this paper is to examine a particular aspect of the history of the watchmaking industry during the eighteenth century. Attention is drawn to overlooked ideas and inventions and how years later they may become profitable business opportunities for entrepreneurs. The approach adopted allows examination of the development and commercialisation of a watch escapement mechanism, the rack lever, within the context of the development of other escapements. The rack lever was an escapement which was initially overlooked in the early part of the eighteenth century but which many decades later was reinvented and became a commercial success in the early nineteenth century. Design/methodology/approach Reference is made to the literature on entrepreneurship and acquisition of knowledge in the eighteenth century and the nature of watchmaking in the same epoch. The literature on entrepreneurship produces a framework for examining the actions that were taken to bring the rack lever escapement to market. The historical context within which the innovations occurred was examined to establish the events and circumstances surrounding the times when commercialisation took place. An account of the commercialisation of the rack lever escapement is presented. Findings The entrepreneurial opportunity examined in this article relates to a need to satisfy consumers with a reasonably accurate and reliable portable time piece. The historical context within which commercialisation took place was found to be significant. Attention to the escapement mechanism in watches was identified as the key to improving performance, and the focus of the paper is placed upon how this opportunity was satisfied through the means provided by the rack lever escapement. Alertness to the potential of already discovered but undeveloped ideas appears to be an additional feature behind the entrepreneurial activity. The paper shows that innovation can be a discontinuous process. It also indicates the relevance of modern-day knowledge brokers in facilitating the process of new product innovation. Originality/value Entrepreneurship and innovation along with research and development are all intrinsically linked in producing goods and services to satisfy customer wants and needs. Together, they represent a cornerstone which helps to establish a business and maintain its continued survival. Importantly, the development of new products is a key contributor to this end and innovation and entrepreneurship play their part in bringing this about. The paper suggests that new ideas can occur which may be deemed unsuitable for commercialisation at one period in time but which can at a future time be considered a temporary solution to meet an unfulfilled need in the market place. It argues for the case for reserving judgement on new ideas that are not commercialised and ensuring that knowledge of them is kept for posterity and made accessible to future generations.

Kinematic Analysis of Swiss Lever Escapement

The escapement mechanism in a mechanical watch movement plays a critical role. Its purpose is to maintain and count the oscillations of the balance wheel. The timekeeping accuracy is therefore regulated. The motion of the escapement mechanism is highly complicated and no in-depth study on its kinematics has been done by now. This paper investigates the kinematics of the Swiss lever escapement which is used in almost all mechanical watches. One half cycle of the motion is described in different phases. Mathematical models for each key component are developed. Simulation result shows that the model is precise in describing and predicting the motion of the escapement. This method is essential for improving and optimizing the design.