Bounds on gravitational parity violation using a rotating torsion pendulum with chiral masses

In this letter we employ recent results on gravitationally induced parity violation with a rotating torsion pendulum whose test bodies are quartz enantiomers (Zhu et al. in Phys Rev Lett 121:261101, 2018) in order to estimate, using a simple model, Hari Dass’s $$\alpha _{2}$$ α 2 constant which parametrizes the strength of parity violation in the gravitational interaction. The result here obtained, $$\alpha _{2}\sim 10^{17}$$ α 2 ∼ 10 17 , is in agreement with estimations based on high resolution experiments performed using chiral molecules, showing that the Hari-Dass’s framework for spin-dependent gravity, together with our simple model, are versatile enough in order to be applied to the analysis of other experimental results involving spin-dependent gravitational effects. Interestingly, it can also be used to constrain indirectly parity-violating effects in macroscopic samples of quartz crystals due to electron–nucleon interactions.

Translations of Steinhausen's Publications Provide Insight Into Their Contributions to Peripheral Vestibular Neuroscience

The quantitative relationship between angular head movement and semicircular canal function is most often referenced to the well-known torsion-pendulum model that predicts cupular displacement from input head acceleration. The foundation of this model can be traced back to Steinhausen's series of papers between 1927 and 1933 whereby he endeavored to document observations of cupular displacements that would directly infer movement of the endolymph resulting from angular rotation. He also was the first to establish the direct relationship between cupular displacement and compensatory eye movements. While the chronology of these findings, with their successes and pitfalls, are documented in Steinhausen's work, it reflects a fascinating journey that has been inaccessible to the non-German speaking community. Therefore, the present compilation of translations, with accompanying introduction and discussion, was undertaken to allow a larger component of the vestibular scientific community to gain insight into peripheral labyrinthine mechanics provided by this historical account.

Implementation of high-precision inertial reference for Taiji-1 satellite and its ground evaluation based on torsion pendulum system

As the key measurement load of Taiji-1 satellite, inertial sensor detects the acceleration disturbance of test mass (TM) under nonconservative force in line with the basic principle of capacitive sensing, while keeping the TM in equilibrium position through electrostatic drive. In order to ensure the smooth progress of the mission, it is necessary to test and evaluate the performance of inertial sensor on the ground. In this paper, a torsion pendulum system is designed to eliminate the influence of the Earth’s gravity so as to meet the requirements of ground test. The experimental results show that the inertial sensor in closed-loop control mode can stably keep the TM at equilibrium position. At the same time, the ground detection of acceleration resolution of inertial sensor is greatly affected by ground vibration noise. If the inertial sensor operates normally in space, its acceleration resolution can reach [Formula: see text], thus meeting the requirement of Taiji-1.