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Matsushita of Japan is developing a long-life lamp that uses microwaves to
make artificial daylight. Today’s light bulbs use a white-hot filament, while
fluorescent tubes use electrodes to create a plasma—but both kinds burn
out after a few thousand hours. Matsushita uses 2.4-gigahertz
microwaves—the same frequency used in microwave ovens—that resonate
and excite indium and bromide compounds, radiating light. Without filaments or
electrodes to wear out, the 50-watt lamp lasts 60 000 hours. It’s not due to go
on sale until 2002, however.