CHEAPNESS HALTS PROGRESS:

Bulb In, Bulb Out (ANDREW RICE, 6/03/11, NY Times Magazine)

The notion of light as a thoughtless commodity would have seemed fanciful to our distant ancestors. Before electricity, light was expensive, a product of exhaustible sources like whale oil. It was Edison who finally took it to the masses in limitless quantities. On Dec. 31, 1879, the inventor invited a crowd of thousands to his laboratory in Menlo Park, N.J., to witness a demonstration of his fantastic innovation, described in a patent as an “electric lamp for giving light by incandescence.” Building on the experimentation of others, Edison had devised a practical method for generating illumination by running a current through a rudimentary filament — a carbonized strip of cardboard — encased inside a vacuum-sealed glass bulb. When the inventor lighted the lamp, it glowed orange, “like the mellow sunset of an Italian autumn,” a contemporary newspaper said.

Almost immediately, though, there were complaints. Some detractors saw electric light as unnatural and reddish, lacking the comforting attributes of a gas flame. But with further refinements — the cardboard filament was replaced by bamboo, and later tungsten — quality improved. At first, bulbs were fairly expensive: in 1891, one went for 44 cents, more than $10 when adjusted for inflation. But Edison accurately predicted that costs would plummet as electricity vanquished all competing technologies.

After that, advancement in home lighting more or less came to a halt. A century ago, incandescent lamps with tungsten filaments lasted about 1,000 hours (same as today’s), were only slightly dimmer and sold in the familiar varieties of 40, 60 and 100 watts. Edison didn’t worry about how many watts they consumed; after all, he also owned an electric company. Efficiency wasn’t an issue until the energy crisis of the 1970s, which inspired compact fluorescents, but they went over poorly and never made much of a dent in the incandescent’s market domination.

The compact fluorescent’s failings were a matter of price — the first ones sold for $25 to $35 a bulb — and taste. American consumers seem to prefer incandescence, for reasons connected to the science of light. “What we term ‘light’ does not exist without the human eye — it’s just radiation,” says Nadarajah Narendran, a professor at the Lighting Research Center at Rensselaer Polytechnic Institute. “Your eye is a detector that senses this energy coming to it at different wavelengths.” Those wavelengths are perceived as colors. Natural light combines all the colors of the visual spectrum. When people complain that fluorescent light is cold, what they’re really describing is an overload of radiation at the bluish wavelengths.

“I don’t think it’s cultural; I think it’s much deeper than that, that our reaction to long-wavelength light is warm and short-wavelength light is cold,” David DiLaura says. Humans don’t see all wavelengths equally well; DiLaura says the eye’s “sensitivity curve” is adapted to the spectral composition of light on the African savanna. The light that surrounds us can have psychological and physical effects. Research has suggested that altering wavelengths can affect students’ attention and that patients on the south side of a hospital, which gets more light, recover more quickly than those on the north. So it’s hardly surprising that the incandescent phaseout has prompted a visceral reaction.

Boosters say L.E.D.’s can be calibrated to create light that’s just as good as — maybe better than — natural. They have long been used for low-intensity applications, like the digits on your microwave, but it was only about a decade ago that a cadre of physicists began to awaken the industry to their wider potential. Roland Haitz, a scientist associated with Lumileds, argued that just as computer chips were becoming exponentially more powerful, L.E.D.’s were getting brighter and cheaper at a predictable rate, a proposition now known as Haitz’s Law. Transitioning to L.E.D.’s, Haitz forecast, would cut the amount of electricity used for lighting by more than 50 percent worldwide, eliminating some 200 million tons of carbon emissions a year.

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