There are not many devices which emit radiation at several million million cycles per second, and those that do exist are unwieldy.

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The new work focuses instead on cold, dense masses of gas that have markedly less random motion, and which emit their radiation in the microwave part of the electromagnetic spectrum.

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The change also will likely squelch pilot complaints about going through full-body scanners, some of which emit low levels of radiation.

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When the sides were heated, the electrons in the atoms become agitated and emit radiation, which bounces around the container, being continuously absorbed and re-emitted.

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The CCK said "sub-standard components" were often used which had not been put through safety checks and might emit higher than recommended radiation levels.

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It was later discovered that the radiation was coming from its cargo of clay tiles, which naturally emit low levels of the stuff.

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