When nearly 30 years ago Dr. Jacob Fraden invented an ear thermometer working on this second principle, the infrared light sensor was so large that he needed a narrow gold-plated reflective tube to channel the light from the ear drum to the sensor.

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But now the simple invention of a cathode ray tube, transforming light into electrons, registering their impact on the magnetic tape, had torn the curtain away.

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Next year we will see this on the Tube and the Docklands Light Railway (DLR) but for now though it won't be included in the daily fare cap, which means passengers never spend more than the price of an equivalent Day Travelcard.

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At one end of the tube is a source of ultraviolet light and at the other a detector.

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Then your doctor uses a thin tube equipped with a camera lens and light (laparoscope) to view the area.

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His device will reportedly stream damp air containing microscopic water particles through a tube, while a laser diode beams light through the vessel onto a sensor located on the opposite side.

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The laparoscope is a flexible controllable tube, with a camera and a bright light at the end, which allows the surgeon to see inside a patient's body.

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Unlike conventional cameras, our femto camera captures an image as one thin slice at a time of one-dimensional space using a "streak tube, " a laboratory instrument that is commonly used by chemists to study light passing through chemical samples.

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