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Consequences of Modern Lamps.

"Lighting has finally arrived."
(Don Thomas, former Sylvania engineer, 1996)

Lighting considerations are now an integral part of the design of houses, offices, factories, museums, and other buildings. Architects and engineers consider not only light levels but also heat generation and long-term costs. And, increasingly, they consider energy conservation. In Thomas's words, they consider "the whole building as an energy-saving box."

The question for this exhibition is to what extent can this be considered a new "revolution"? In 19th Century Consequences we suggest that Edison's invention (with help from many others) led to two dramatic changes. One was our complete control over interior lighting. The second was the power infrastructure that brought electricity into homes and offices and made it economical to introduce a wide variety of electrical appliances and fixtures.

For 20th Century Consequences we would like you to consider two additional changes, still in process. One is the control we are achieving over exterior light. The second is the degree to which lighting is contributing to our understanding of the importance of energy conservation.


Exterior Lighting

"Some people want a lot of light and others don't."
(Robert Levin, OSRAM SYLVANIA scientist, 1997)

Strretlighting the side of a building, 1992
Example of "light trespass"
S.I. image #99-4118

Highly efficient lamps have made it practical to convert night into day around shopping malls, football stadiums, parking lots, filling stations, and barnyards. Not everybody thinks all of this light is necessary or desirable, like the people living in the apartment building to the right. People inside and outside the lighting industry now weigh costs and benefits when considering exterior lighting. But for better or worse, the changes in our lives have been significant.

On the side of benefits, traffic studies since the 1930s have indicated the safety value of street lighting. This includes well-lighted signs that can be read at a glance. Development of bright, reliable lights for use on vehicles has also advanced safety, though misaligned headlights sometimes create problems.

Lighting of large working areas like rail yards, docks, and quarries not only allows activity to proceed after dark but also aids in maintaining security. Airport lighting, with its many special devices, provides a prime example. Overnight delivery services like Federal Express and UPS could not function without night-capable airports.

The ability to illuminate stadiums, racetracks, and playing fields makes it possible for those who work during daylight hours to enjoy the diversion of night-time sports, either as a participant or as a spectator in person or on television. Evening concerts in large outdoor venues are also routine.

While some debate the actual effect of exterior lighting on criminal activity, most agree that people walking in well-lighted areas feel safer. Parking lots sprout lamp posts like trees. Many home owners mount powerful lights around their property, sometimes coupled to motion detectors, to deter crime–as well as smaller walkway and porch lamps to deter injuries.

Neon tubes, fluorescent signs, and lighted store-fronts and bill-boards have become advertising staples. Brilliantly illuminated "White Ways" once attracted shoppers to the downtown stores of major cities in the early 20th century. Now the lights of car dealerships, retail strip centers, and fast-food restaurants vie for attention along miles of major suburban routes.

The costs of exterior illumination began to be felt during the 1970s, when people questioned the amount of energy being used. Despite protests from businesses, illuminated advertising was curtailed for a time. Some streetlights were turned off. Engineers and designers started reevaluating both lighting standards and equipment designs. But as the energy crisis passed, the general public lost interest in the issue and the lights were turned back on.

Astronomers, however, began to feel pressure from increasing levels of "sky glow." Observatories built on top of remote mountains in the late nineteenth and early twentieth centuries found themselves trying to conduct sensitive research thru a haze of suburban lights. The problem became worse as more municipalities replaced older lamps with efficient metal halide and high-pressure sodium lamps. These lamps radiated many wavelengths of light rather than only one or two, making it difficult for astronomers to filter out the artificial light.

Environmental groups and campers also began to notice that night skies were fading into the haze. The term "light pollution" has been coined to describe the problem, and some local governments have enacted ordinances to address it. Wasted light, or light that does not provide illumination on the target surface, is a major cause of light pollution. Light that reflects off of the target surface into the sky is another.

While industry and interest groups debate the proper response, most agree that much of the problem stems from "bad lighting." Fixtures that throw light above the horizontal or that are misaligned are two of the culprits. Many people understand the annoyance of a streetlight that shines in the bedroom window.

New "full cut-off fixtures" have been developed that minimize "light trespass" by directing more light toward the target. Lower power lamps which provide adequate illuminance without excessive reflection are now commonly specified. Low-pressure sodium lamps, relatively easy for astronomers to filter out, are now used around most observatories.

These steps not only reduce light pollution but improve energy efficiency, an aspect of exterior lighting that is starting to attract attention once again.


Energy Conservation

"When the well's dry, we know the worth of water."
(Benjamin Franklin, in Poor Richard's Almanac, 1746)

North America from space.
"North America from Space"
S.I. image #99-4114

As Franklin experimented with static and lightning, he could not have imagined a day when Poor Richard's truism would apply to electricity. We, however, are reminded of the worth of electric power whenever the lights suddenly go out. In 1998 nearly 70 percent of U.S. electricity was generated using nonrenewable fuels, and we've seen what happens to the worth of oil when wells go dry.

The movement to conserve energy has been driven by several factors: the high cost of new electric generating plants, the oil crisis of 1973, and a moral desire to help conserve the world's limited resources. But in the United States, still a land of abundance, the impact of these factors on individuals is often short-lived.

Many manufacturers of electric appliances have tried to incorporate energy saving features into their designs, often with encouragement from agencies like the U.S. Department of Energy and the Environmental Protection Agency. More efficient refrigerators, clothes washers, and water heaters have been introduced into the market. Many computers sport an "Energy Star" label, attesting to efficient features.

Two problems exist, however. First, major appliances, with design lives of 10 years or more, are only replaced when they break or wear out. Even if every person chooses an efficient replacement, making significant improvements will be slow. Since new, efficient designs are generally more expensive than older, less efficient designs, many people decide to buy the cheaper product–the second problem.

Perhaps what is needed is an appetizer. Might electric light, our most common and obvious use of energy, provide an example? Efficient lamps cost more to buy but save money in the long run because they use less energy and last longer. As people begin to make conscious choices about changing light bulbs in their homes, could they develop an instinctive understanding of conservation? If so, it may become second nature to weigh long-term energy savings against short-term costs.

To 19th Century Preconditions To Consequences of Edison's Lamp

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