Free Republic

New paint blocks out cell phone signals ROCHESTER, N.Y., March 1 (UPI) -- A Rochester, N.Y., company has developed paint that can switch between blocking cell phone signals and allowing them through. "You could use this in a concert hall, allowing cell phones to work before the concert and during breaks, but shutting them down during the performance," said Michael Riedlinger, president of NaturalNano. Using nanotechnology, particles of copper are inserted into nanotubes, which are ultra-tiny tubes that occur naturally in halloysite clay mined in Utah. Combined with a radio-filtering device that collects phone signals from outside a shielded space,...