"While an operational device is at least five years in the future, developers of what can be loosely termed a force-field machine say it has cleared major theoretical hurdles. To demonstrate their claim, they invited POPULAR MECHANICS to visit their Huntsville, Ala., laboratory to see the most important component of their proof-of-concept demonstrator. It is a 12-in.-dia. high-temperature superconducting disc (HTSD). When the force-field machine is complete, a bowling ball placed anywhere above this disc, which resembles a clutch plate, will stay exactly where you left it."~~~JW