sonic

Gentlemen, welcome to the Holodeck. A team of Japanese scientists has finally created holograms you can touch.

Since the bombing of the U.S.S. Cole in 2000, protecting docked ships-both military and commercial-has been a big priority in the fight against terrorism. The Department of Homeland Security has already awarded $489 million to help guard the nation´s ports, spurring a number of innovative ideas, the latest of which is an underwater system that blasts enemy swimmers with painful acoustic waves. Patented by the Raytheon Corporation last October, the system is the brainchild of former Navy and Raytheon acoustics expert Frederick Di Napoli. His scheme is simple: Generate a region of high-pressure, low-frequency sound around the ship, creating a sort of sonic fence that â€shocks†anything that swims through it. Although a diver would probably flee from pain, Di Napoli says, "you could really dial up the pressure and make it lethal if you had to."

When a Concorde jet on its way from Paris to New York crashed on July 25, 2000, killing all 109 people aboard and four on the ground, the event was not simply a tragedy -- it seemed a metaphor for the sorry state of supersonic air travel.