Environment

The magic lamp

Energy conservation is the bottomline of the latest innovations. A new light bulb has the combined attractions of less energy, more efficiency and a longer life. Filled with inert gas and sulphur, the bulb gives an output equivalent to several hundred mercury lamps. Besides, the light has sunlight-like radiance and less ultraviolet content which makes it suitablefor growingplants andfor displaying works of art. Apparently the bulb can burn on endlessly as it has no filament to burn out

DTE Staff

A NEWLY invented light bulb promises tooffer significant energy savings and better light to future users worldwide,according to the US department ofenergy (DOE). The bulb is filled withinert gas and a small amount of sulphurthat is bombarded by microwaves toproduce luminescence. The WashingtonPost writes, "one golf ball-sized sulphurbulb, when irradiated by the kind ofcompact microwave generator found inordinary kitchen ovens, puts out asmuch light as hundreds of high-intensity mercury vapour lamps".

A small microwave generator at thebase of the bulb bombards the inert gas,heating it. The hot gas energises electrons in the sulphur, which then emits alarge amount of visible light. The bulbitself is rotated quickly by a motor tocool it - otherwise it would melt.

According to DOE, the new lightinghas attractive optical qualities. Expertsnote that the 'new-fangled' bulb emitsless ultraviolet light than traditionallarge-area lighting, making it favourablefor displays or works of art. In addition,the new kind of light, which is opticallysomewhat similar to sunlight, seems tobe good for growing plants.

At the moment, nobody knows howlong the new bulbs will last. Since theydo not have electrodes, there are no filaments to burn out - so they may last along time. Light output does not seemto diminish after extensive use - andsince this high-efficiency lamp does notmake use of mercury, there is no toxicmercury to dispose off.

The new lighting "technology islikely to usher in high quality,high-efficiency illumination for largeindoor or outdoor spaces" once itis made commercially availableaccording to the US Information Service'Science Update. The DOE announcedlast year that it was "inauguratingthe use" of the new light bulb which hasbeen installed on an experimental basisat its Forrestal headquarters buildingand at the Smithsonian National Airand Space Museum in Washington DC.