Electromagnetism acts oddly in device

Using little fiberglass boards and copper wires, a group of California physicists has created a structure that behaves as though it were from some strange, mirror world.

Signs of their creation’s oddness showed up when David R. Smith and his colleagues at the University of California, San Diego shined a beam of microwaves through it. As expected, the beam bent, or refracted, as it exited the material. What’s bizarre is that the beam bent at an angle opposite from what it would have exiting from any other known material. Smith, Richard A. Shelby, and Sheldon Schultz describe their invention and its effect on microwaves in the April 6 Science.

The researchers have assembled a grid of thin fiberglass boards with straight copper wire segments glued to their backs and C shapes of copper plated on their fronts (SN: 3/25/00, p. 198).

Currents induced in the wires and the Cs by the microwaves generate large magnetic and electric fields that oppose the microwaves’ fields. The presence of those contrary fields flips the tilt of the refracting microwave beam to the angle opposite that which it would take leaving ordinary materials, the scientists say. Although the microwaves’ peculiar trajectory violates no laws of physics, “it really does counter your intuition,” Smith admits. The researchers say such materials could lead to novel microwave lenses, antennas, and other devices.

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