Tag Archives: patents

Wirelessly powered non-magnetic rotary actuator

(image of mechanism #77 from Henry T. Brown’s Five Hundred and Seven Mechanical Movements, via 507movements.com) The leading systematic uncertainty in our group’s test of the equivalence principle is variations in the local gravity gradient.  The gravity gradient is the spatial derivative of the gravitational field—the amount of change in the strength and … Continue … Continue reading Wirelessly powered non-magnetic rotary actuator

A device to measure picoradians

The science data for our torsion-balance experiments is collected by measuring the rotation of the pendulum using laser autocollimators. In these autocollimators, light from a laser diode is collimated by a lens, reflected off a mirror on the pendulum, refocused by the original collimating lens, and directed onto a position-sensitive photodetector by a … Continue … Continue reading A device to measure picoradians