The plenty celebrated during the holidays in Chicago obscures an elemental scarcity: light.
Yet, no amount of eggnog, fruitcake or latkes fully compensates for the pervasive cloud cover and the sun’s low arc across the city’s sky this time of year.
From the time prehistoric people gathered around a campfire to cook food and harden spear points, to today, when indoor lighting keeps factories churning out goods 24 hours a day, light and life have formed an inseparable weave. The technological innovations for harnessing and distributing light have radically altered society, fostering literacy, urbanization and industrialization.
“You live by the light,” said Pamela Horner, education director for Osram Sylvania, an electric lighting manufacturer in Danvers, Mass. “Our world has evolved, in many ways, because of it.”
Before the technology for creating light extended much beyond rubbing two sticks together, though, the emotional impact of light was known and honored. Many ancient texts talk of its power. Best known, perhaps, is the book of Genesis:
And God said, Let there be light: and there was light.
And God saw the light, that it was good: and God divided the light from the darkness.
And God called the light Day, and the darkness he called Night. And the evening and the morning were the first day.
The Egyptians, bathed often in sunshine, wrote eloquently of its importance. An Egyptian text from around 1500 BC paid homage to Aton, the sun:
Thou dost appear beautiful on the horizon of heaven
O living Aton, thou who wast the first to live
When thou hast risen on the eastern horizon,
Thou hast filled every land with thy beauty. . .
Kent Weeks, professor of Egyptology at American University in Cairo, Egypt, said ancient people recognized that light was central to their existence.
“Ancient Egyptians saw light not as the original source of life, but as the foundation of all life,” said Weeks. “Without light, there would be no existence.”
If fires likely were the first way that early people harnessed light, other methods soon followed. Torches, oil lamps in vessels composed of seashells, bronze and clay and candles were used for thousands of years.
“In Europe, before 1700, most of the lighting was by flame,” said Wilbert Hasbrouck, a Chicago preservationist architect. “If you go to some of the cathedrals, the ceilings will be black, and that is from smoke.”
In homes, lighting was by a small flame–the candle or oil lamp. And the limited light it threw off influenced home design.
“From the founding of the U.S. in 1776 to about 1850, interiors were extremely vivid colors, almost garish by today’s taste,” said Hasbrouck. “Part of that is a consequence of low light.”
The simple flame of a lamp was hardly improved upon until the middle of the 18th Century when it was discovered that by running the wick through a central burner enclosed in a metal tube the intensity of the flame could be controlled. Soon after came the realization that the flame could be intensified by aeration and a glass chimney.
Until the late 18th Century, the primary fuels burned in lamps included vegetable oils such as olive oil, and tallow, beeswax, fish oil and whale oil. Then coal gas became available and in the middle 1800s most cities in the United States and Europe had gas-lighted streets and gas lines to some private homes and offices
It was the invention of the lamp mantle in the 1820s that made gas lamps so much more efficient than candles or open-flame lamps. With a mantle lamp, a controlled amount of air was admitted to the gas current, which produced a high-temperature flame that heated a refractive, noncombustible material to a very high temperature.
This material, not the flame, was the source of light. The higher it could be heated, the whiter the light became. Mantles were generally made of cotton threads impregnated with thorium and cerium salts.
Still, many buildings in Chicago also depended on daylight–that is, windows–along with gas or oil lamps until the time of the Chicago Fire in 1871.
But after the fire, the steel frame was developed, which supported much larger windows, said Hasbrouck. These advances in technology helped to spur the demand for more offices, sending buildings soaring and, in turn, fostering urbanization.
Still, however, light was at a premium, and a variety of design tricks were employed to enhance the light levels in building interiors. Special prisms on windows bent incoming light, bouncing it farther into a room than it would otherwise penetrate. Some structures, such as Chicago’s famous Rookery, were designed around a central light court, whose huge rooftop skylights sent sun into the middle of the building.
As the 19th Century edged into the 20th, lighting technology underwent a dramatic change. In 1879, Thomas Edison introduced the first practical electric lamp. People had been experimenting with lamps and bulb-like devices for years. But Edison’s genius was to be the first to couple his lamp design with a means of delivering the electricity–a power plant. The pairing moved the invention out of the laboratory and into society. Gradually, entire cities were lit.
But at first, people noticed little difference. Early electric lights were perhaps twice as bright as their gas forerunners, which were already so dim that a 100 percent improvement was not particularly remarkable. Over time, electric lighting improved in brightness.
Edison “wanted to open up the night and light up the darkness so that we could do things at times” we wanted to do them, not when daylight was available, said Horner. “You had to transmit electricity to people’s homes, or that wouldn’t work.”
Lighting technology spurred industrialization, which led to advances in a variety of areas, including communications technology.
“There was so much work that needed to be done in order to survive, we needed to carve out the night,” said Horner. “And all of this was coupled with the desire to be more productive, the desire to make more use of one’s time.”
What enhanced productivity during the first half of the 20th Century was the development of a usable fluorescent lamp. The innovation was unveiled during the 1939 New York World’s Fair.
Incandescent lamps, such as those developed by Edison, are inefficient. An incandescent lamp radiates light from a thread or filament, generally made of tungsten today. So that the filament does not burn itself out, it is enclosed in a vacuum or inert gas. In essence, light is produced because an electric current passing through a filament is heated so hot that it glows.
By comparison, a fluorescent light gives off light by having electricity flow though a gas and then producing ultraviolet rays, which interact with a phosphorus coating. That coating glows, or fluoresces.
“It was a giant leap in lamp efficiency, a giant leap forward,” said Horner. “Fluorescent light is the primary source of light, especially if you want to talk about commercial use of light, in the world because it is more economical.”
Such efficiencies may warm the hearts of accountants the world over, but generations of office workers, schoolchildren and swimming suit shoppers have cringed under its harsh glare. And although it is improving, many people still think of it as the light that lends their skin a peculiar cast.
“Think of fluorescent lighting as the smirk on the face of the boss that he gave you something cheap,” said Mark Rea, director of the Lighting Research Center at Rensselaer Polytechnic Institute in Troy, N.Y.
Another major innovation–at least from the standpoint of lighting designers and marketers–occurred in the 1960s with the development of high intensity discharge metal halide lamp and, later, high pressure sodium lamps.
Large and bright, these lamps could easily light up the outdoors, illuminating the growing network of highways, calling attention to used-car lots and lighting up shopping centers. These newer kinds of lamps deliver more light per watt than incandescent bulbs, and have a far longer lifespan, easing maintenance. And the new lamps function in all temperatures. By contrast, fluorescent lights are sensitive to extremes of cold and hot, and may become dim.
“People, like moths, are attracted to light,” said Rea. “It’s attention-getting.”
But the burgeoning array of outdoor lighting, which washes out the night sky, and a growing desire for access to sunlight inside of buildings is causing a change in how people, designers and engineers look at light. In coming years, the way light makes us feel, not just the way it lights our homes, offices and factories, is likely to become increasingly important.
“There are a lot of psychological aspects of lighting that are just as important as physical,” said Robert Shook, principal at Schuler and Shook, a lighting design consulting firm in Chicago.
“Our general knowledge of light has moved to the front in the last 20 years or so,” he said. “Like any science–and the study of light is a science as well as an art–we just discover more about everything as our culture progresses. We discover that you can’t just fix lighting or just design lighting by working around the physical aspects, but that you must be just as aware of the psychological aspects.”
And as the study of light progresses, it may become clear that the familiar flame of prehistory is an elusive daily companion.
“I find lighting and light to be kind of an enigma. We’re surrounded by it. We come into the world and it’s there, and we feel we know it, that everybody’s an expert,” said Horner, of Osram Sylvania. “It surrounds us so much we have virtually become oblivious to it.
“But on the other hand, we don’t know it.”
