The map of the millennium is drawn by thinkers

If it were necessary to define the modern era in one word, technology would be that word. We live in a world pulsing with technology - digital phones and cameras, the Internet, the space shuttle, cloned sheep, and countless other wonders. But the scientific theories upon which human invention rests often get short shrift and are little understood. Today, in the first of the Monitor's special millennium reports, we look back over the past 1,000 years and chronicle the major scientific theories and the changes they brought. Technological progress, or advances in the human condition, guided our selections.

On July 4, 1054, a great light from an exploding star appeared in the constellation Taurus. Observers in China, Japan, and the Middle East recorded this bright star, or supernova, which created the Crab Nebula and was visible even in daylight. The Anasazi, or "ancient ones," in the American Southwest painted it on a canyon wall.

To these skywatchers at the beginning of the millennium, the heavens determined the fate of men. The Anasazi aligned their great houses and kivas with sacred celestial objects, whose movements determined when to plant, sacrifice, or start a pilgrimage. Chinese court astrologers kept precise records of celestial events to alert the emperor to good or bad times to come.

Such close observations of the night skies marked a giant step away from peering into the entrails of sacrificed animals to predict the future - the "science" of many ancient peoples.

But observation alone did not produce the surge of scientific discovery that marks the end of this millennium, especially in the West. That required new instruments and an openness to the culture of science, especially a capacity to share information and bring observation under the discipline of mathematics.

Other civilizations made important scientific advances, but failed to develop them. China built an astronomical clock in 1090, centuries before anything comparable in the West. Chinese astronomers recorded observations of supernovae as early as AD 185, but emperors insisted that astronomical records be kept strictly a state secret. (Those who could read the skies might use this knowledge to unsettle the empire.) And by the mid-15th century, China had sealed itself off from outside contact.

Similarly, up to about 1500, Islam had a much higher level of scientific achievement than the West. Arab thinkers developed trigonometry and algebra and made important advances in optics and chemistry. Their astronomers developed instruments to use the stars to determine absolute direction, to ensure that all mosques faced Mecca.

By the 10th century, Muslims could calculate the exact time and had observed all that could be observed in the skies without a telescope, including sun spots. Their astronomical tables were the textbooks for Europe's great astronomers.

But the Arab world was not of one mind on the usefulness of wide-ranging scientific pursuits. "The Arabs built on what they got from the Greeks, but their natural philosophers that were doing this were under a cloud and were not fully accepted," says Edward Grant, distinguished professor emeritus in the history and philosophy of science at Indiana University, who recently completed a second book on this subject.

European universities taught natural philosophy, but a student in the Arab world had to seek out a teacher. "They called the Greek sciences the 'foreign' sciences. Natural philosophers were often physically or verbally attacked by those that felt that pure Islam was under threat," he adds.

However, without the contribution of Arab thought, including passing along Greek ideas, the subsequent breakthroughs in science in the West would have been inconceivable, he says.

On Nov. 11, 1572, Danish astronomer Tycho Brahe noticed that the brightest star in the night sky had never appeared before. The new star, a supernova in the constellation Cassiopeia, prompted a very different reaction than the exploding star that dazzled observers at the beginning of the millennium. This was no sign that the gods were restless or that a plague, famine, or war was about to break out on earth. For Tycho, the observation was a new fact that didn't fit expectations - and something that a curious mind could try to explain.

According to the prevailing view of cosmology, the earth was the fixed center of the universe, and the stars moved on a rotating spherical dome above them. In this view, there could be nothing new in the heavens - not even a bright new star.

Tycho had studied the Arab astronomical tables, and he knew the night sky. Two years before this sighting, he had invented a new device to measure the position of stars - a 30-foot-high quadrant of oak and brass. Unlike other astronomers in Europe, he didn't need to guess if the new star was fixed or moving. (It was fixed.)

The quality of his observations set a new standard of scientific work, and word of his analysis spread fast. As a result, the Danish king diverted nearly a third of the national budget to finance the most advanced research complex in Europe for the world's new most-celebrated astronomer.

It would take Galileo Galilei and the invention of the telescope 27 years later to settle the question of what the new view of the universe should be. But Tycho's celebrity signaled that a new scientific culture was taking hold in Europe - a culture of close observation and analysis that could capture the interest of a broad public and the backing of ambitious states.

The shared belief of science

"Europeans in the Renaissance began to share a belief that science can explain the world better than any other way - that we can explain, understand, and control the physical world. A thousand years ago, most people wouldn't have made those statements," says Michael Sokal, program director for science and technology studies at the National Science Foundation.

There's no one reason that Europe - "a little peninsula on the cape of Asia" - should have launched such a scientific revolution. Some historians note that Europe's dominance in science coincided with its conquest of the seas and a vast expansion in commerce. Others cite the importance of a vibrant print culture or Europe's concentration of cities, which allowed new ideas to circulate quickly.

Most scholars still support some version of German sociologist Max Weber's claim at the turn of the 20th century that Europe's dynamism was related to a change in thought, especially the Protestant ethic. The collapse of religious consensus in 16th-century Europe, and the wars that grew out of it, convinced many that mankind should shift from disputing God's Word to investigating His works.

"Protestant scientists like Robert Boyle defined the scientific method - the cautious, careful, tedious discipline that science requires - as a form of work ethic," says Margaret Jacob, a professor of European history and science at the University of California, Los Angeles.

Science and the Protestant Reformation

"Science became an expression of piety and very much a part of Protestant English households in the 17th century. Educated men and women came to believe that they should know this. They became interested in home experiments and bought orreries [mechanical models of the heavens] for their living rooms," she adds.

Latin was replaced by mathematics as the new language of science. New scientific journals spread discoveries fast. By the end of the millennium, gains in science and technology were piling up exponentially.

Scientists call the 20th century the golden age of mathematics, because so many other disciplines began reducing their work to mathematical expression.

"There is no doubt that science is the most extraordinary collective achievement of the human intellect in the 20th century," says Martin Rees, Royal Society professor at Cambridge University and Britain's astronomer royal.

"At the beginning of the century, people had no concept of just how much progress the world was going to make," he adds.

Astronomers are exploring deep connections between stars and atoms. Powerful new telescopes like the Hubble Space Telescope (1990), the Extreme Ultraviolet Explorer (1992), and the Chandra X-ray Telescope (1999), allow scientists to study stars deep in space and along the whole energy spectrum. To scientists at the end of the millennium, supernovae are more than a curious bright light. Their densities, dust disks, and massive stellar winds are opening windows on the origins of the universe.

The dominance of Europe and, later, the United States in scientific discovery carried through the millennium. Nearly 3 in 4 Nobel

Laureates in science have been scientists based in the US, Britain, or Germany, since the prize was first awarded. Experts say this is due, at least in part, to the investments needed to sustain big science.

"Science has become quite expensive in the modern age. You need strong economies to put the resources together to keep launching satellites and more powerful telescopes," says Mario Livio, senior astrophysicist at the space Telescope Science Institute in Baltimore, Md.

A social elite based on knowledge?

But this brilliance in science at the top of a handful of American universities does not extend deep into American public schools or popular culture. American high school students ranked poorly compared with the rest of the world on a recent international survey of math and science.

"It's clear that science is at the center of our culture. But we're having difficulty educating our students to become participants," says Timothy Ferris, a professor at the University of California, Berkeley and a science writer.

In this effort, the resources of the Internet could be as important as movable type in opening the possibilities of science to a wider audience. A modem can bring the latest images from new telescopes or unmanned space probes to labs, or laptops on a kitchen table. A fifth-grader could play a part, or be the first to recognize in the data being processed on his classroom's computer intelligent life in space.

"It hasn't begun to dawn on people what unmanned [space] exploration means when combined with an Internet world. Live images from the surface of Mars or Venus can be accessed simultaneously at 100 million nodes around the world. When you go to your science class, there is a possibility that you will be the person to discover extraterrestrial life on Europa or a fossil on Mars," says Professor Ferris.

Bob Evans, a retired Methodist minister in Hazelbrook, Australia, still studies the night sky any chance he can. He knows it well. Since 1981, he has discovered 32 supernovae - more than any other private individual has - using a 10-inch telescope that he can carry around in the back of his car.

"You have to learn where the galaxies are and look at them regularly. You learn what they're supposed to look like. If you see something new, it gives you a surprise. You just hope you're the first to see it," he says.

The Rev. Mr. Evans is one of about 50,000 serious amateur astronomers who regularly report results of sightings to professional groups, via the Internet.

"Our members observe the stars, and when an explosion occurs on a specific star, we inform the professional astronomers, and they turn the satellite to look at it. It's a partnership that has been extremely beneficial," says Janet Mattei, director of the American Association of Variable Star Observers, based in Cambridge, Mass.

But Evans says that what drives him is a love for observing night skies.

"I started off as a kid looking up at the stars, and it fascinated me. It makes you feel humble about how big nature is. And if a person has the feeling that the universe is created by God, it gives you a sense of how great God is, too," he says.

(c) Copyright 1999. The Christian Science Publishing Society