Einstein’s nearly 90-year-old General Theory of Relativity is getting one of its most rigorous tests high above the Earth. The Gravity Probe B (GP-B) has been in orbit since April 2004 conducting what could be a two-year test of the so-called “frame-dragging” effect—the “twisting” of the local space-time fabric. Critical to the tests: advances in design of gyroscopes.
The Probe has four gyros. The gyro rotors are made of fused quartz and ground to near-absolute sphericity. The near-perfection of the ping pong-size gyros is necessary because imperfection can distort their position: They will be pointing to a reference guide star. The frame dragging that distots the space-time fabric, theoretically would distort the gyroscopes too. But imperfections in the gyros themselves could also cause distortion, invalidating the experiment.
Engineers levitated the rotors with three saucer-shaped electrodes so they could suspend them in their cavity without disturbing the spin. To get and keep the rotors spinning, they directed a precise stream of helium gas at the rotors. And, they used superconductivity as the basis of a noninterfering pointer readout based on the superconducting quantum interference device (SQUID). It senses any angular shift in the rotor spin axis.
Though the GP-B has another 16 or so months to go, engineers have already achieved successes, including advanced gyro fabrication, near-perfect elimination of interfering magnetic fields, and telescope pointing and control.
By experimenting with the photovoltaic reaction in solar cells, researchers at MIT have made a breakthrough in energy efficiency that significantly pushes the boundaries of current commercial cells on the market.
In a world that's going green, industrial operations have a problem: Their processes involve materials that are potentially toxic, flammable, corrosive, or reactive. If improperly managed, this can precipitate dangerous health and environmental consequences.
A quick look into the merger of two powerhouse 3D printing OEMs and the new leader in rapid prototyping solutions, Stratasys. The industrial revolution is now led by 3D printing and engineers are given the opportunity to fully maximize their design capabilities, reduce their time-to-market and functionally test prototypes cheaper, faster and easier. Bruce Bradshaw, Director of Marketing in North America, will explore the large product offering and variety of materials that will help CAD designers articulate their product design with actual, physical prototypes. This broadcast will dive deep into technical information including application specific stories from real world customers and their experiences with 3D printing. 3D Printing is