The magic lamp
A NEWLY invented light bulb promises to offer significant energy savings and better light to future users worldwide, according to the US department of energy (DOE). The bulb is filled with inert gas and a small amount of sulphur that is bombarded by microwaves to produce luminescence. The Washington Post writes, "one golf ball-sized sulphur bulb, when irradiated by the kind of compact microwave generator found in ordinary kitchen ovens, puts out as much light as hundreds of high-intensity mercury vapour lamps".
A small microwave generator at the base of the bulb bombards the inert gas, heating it. The hot gas energises electrons in the sulphur, which then emits a large amount of visible light. The bulb itself is rotated quickly by a motor to cool it - otherwise it would melt.
According to DOE, the new lighting has attractive optical qualities. Experts note that the 'new-fangled' bulb emits less ultraviolet light than traditional large-area lighting, making it favourable for displays or works of art. In addition, the new kind of light, which is optically somewhat similar to sunlight, seems to be good for growing plants.
At the moment, nobody knows how long the new bulbs will last. Since they do not have electrodes, there are no filaments to burn out - so they may last a long time. Light output does not seem to diminish after extensive use - and since this high-efficiency lamp does not make use of mercury, there is no toxic mercury to dispose off.
The new lighting "technology is likely to usher in high quality, high-efficiency illumination for large indoor or outdoor spaces" once it is made commercially available according to the US Information Service' Science Update. The DOE announced last year that it was "inaugurating the use" of the new light bulb which has been installed on an experimental basis at its Forrestal headquarters building and at the Smithsonian National Air and Space Museum in Washington DC.