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The infrared light emitted by light bulbs can be harnessed to make them even
brighter, says General Electric of New York (GB 2362260). Today’s
spotlight-style bulbs normally use a silvered reflector behind the filament to
focus the light into a beam. GE’s new lamp is especially bright because it has
six filaments. But to make it shine even more brightly, the quartz bulb is
coated with tantalum oxide, which lets visible light pass through but reflects
infrared. So the infrared bounces back and makes the filaments even
hotter—generating more visible light.