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A Sonic Black Hole

A laboratory black hole, made using sound waves and exotic matter, might prove Stephen Hawking right

3 min read

18 June 2009—In a first step toward observing the faint radiation that a black hole is supposed to emit, an Israeli team of physicists led by Jeff Steinhauer at Technion-Israel Institute of Technology has created an analogue of a black hole in the lab using sound waves and a frigid state of matter called a Bose-Einstein condensate. The theorist Stephen Hawking has predicted that black holes are not totally black but instead give off a mysterious and faint glow, known as Hawking radiation. Steinhauer says that his lab-created black hole could ultimately lead to the discovery of this radiation.

William Unruh of the University of British Columbia, the theorist who in 1981 first outlined the principles of creating an acoustic analogue of a black hole, calls the work ”very exciting.”

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Economics Drives Ray-Gun Resurgence

Laser weapons, cheaper by the shot, should work well against drones and cruise missiles

4 min read
In an artist’s rendering, a truck is shown with five sets of wheels—two sets for the cab, the rest for the trailer—and a box on the top of the trailer, from which a red ray is projected on an angle, upward, ending in the silhouette of an airplane, which is being destroyed

Lockheed Martin's laser packs up to 300 kilowatts—enough to fry a drone or a plane.

Lockheed Martin

The technical challenge of missile defense has been compared with that of hitting a bullet with a bullet. Then there is the still tougher economic challenge of using an expensive interceptor to kill a cheaper target—like hitting a lead bullet with a golden one.

Maybe trouble and money could be saved by shooting down such targets with a laser. Once the system was designed, built, and paid for, the cost per shot would be low. Such considerations led planners at the Pentagon to seek a solution from Lockheed Martin, which has just delivered a 300-kilowatt laser to the U.S. Army. The new weapon combines the output of a large bundle of fiber lasers of varying frequencies to form a single beam of white light. This laser has been undergoing tests in the lab, and it should see its first field trials sometime in 2023. General Atomics, a military contractor in San Diego, is also developing a laser of this power for the Army based on what’s known as the distributed-gain design, which has a single aperture.

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