You get up in the morning and put on your glasses, snap on the radio, and grab the morning paper. Already you have directly benefited from three of the greatest inventions of the last 1,000 years: the glass lens, wireless communications, and the printing press. Later you ride the subway to work, where you use a computer and make telephone calls—three more developments made possible by scientific breakthroughs during the fertile millennium that is now coming to an end.

The last 1,000 years have produced an incredible number and variety of scientific and technological breakthroughs—but which of these were the most important? Narrowing a list of the thousands of inventions made since the year 1000 to the ten greatest requires some stringent criteria. The qualifying inventions either provided radically new ways to do an important job, or they made possible tasks that were previously unimagined. Their impact was felt, if not right away then eventually, by a large portion of humanity. These developments have enabled significant new technological innovations and scientific discoveries. And finally, they have had an enduring effect on the world.

The inventions that meet these criteria, in chronological order, are the compass（指南針）, the mechanical clock（機械表）, the glass lens（鏡片）, the printing press(印刷機), the steam engine(蒸汽機), the telegraph(電報機), electric power(電), wireless communications(無線通信), antibiotics(抗生素), and the transistor(晶體管).

Fundamental Breakthroughs

Missing from this list are many extremely significant technological advances, including the airplane, telephone, automobile, and computer. In many cases these inventions were omitted because they are based on earlier developments or breakthroughs that are included in this discussion. While a device that could artificially transmit the human voice was clearly significant, the telephone was not really a fundamental leap when it was developed in the 1870s. That came decades earlier, when the first telegraph machine ushered in our present era of instantaneous communications. Indeed, American inventor Alexander Graham Bell was working on ways to improve the telegraph when he devised the telephone. The phone was, in origin and in practice, an improvement on existing technology.

Similarly, the steam engine brought for the first time the possibility of rapid transportation. Before that, no person could travel on land faster or farther than an animal could hold out. After the invention of the steam engine, the only limits were the amount of fuel and the reliability of the machine—both factors that people could control. The airplane, the automobile, and even the rocket are based on this basic idea of deriving huge amounts of propulsive power by burning fuel. Once the steam engine put that idea into practice, developments such as the internal-combustion engine—which now powers the world's millions of automobiles—came as almost inevitable refinements.

In considering the ten most significant inventions of the past 1,000 years, a subtle distinction must be made: The difference between “invention” and “discovery” is not as clear as one might think. A discovery can be as simple as the observation of a previously unnoticed phenomenon, while an invention is a human-devised machine, tool, or apparatus that did not previously exist. For example, ancient people discovered that drops of water and certain gemstones distorted light in a predictable way. However, it was not until medieval times that others tried to reproduce this effect by applying new glass-shaping technology to the formation of lenses—the basic elements of spectacles, microscopes, telescopes, and cameras. Similarly, people knew about and studied electricity as a force of nature for thousands of years, but it was the technological leap of mass-producing electricity and delivering it to homes and factories in the early 20th century that transformed the world.

The Compass

The explorations that led to the European arrival in the Americas required that mariners know which way they were going. On clear days and nights, the position of the Sun and stars (especially the North Star) yielded this information. However, long voyages inevitably included sustained periods of cloud cover, and this threw navigators off course. The invention of the compass made possible the exploration of distant, uncharted lands.

The origin of the compass is cloaked in obscurity. Ancient peoples knew about the peculiar properties of lodestone (magnetite)—that a sliver of this material, hung from a thread, will point in the direction of the North Star. The idea of mounting a needle-like piece of the stone in a case that has directions marked on it seems to have been a European invention of the 13th century, although it is possible that Arab traders brought the idea from China. In any case, by the end of the 14th century the compass was widely used.

Of the many technologies that aided navigation over the millennium, the compass is most fundamental. Using its seemingly magical sense of direction, sailors grew bold, striking out on longer and longer voyages of discovery. With this tool in hand, European explorers journeyed for the first time to the Americas—perhaps the single most transforming event of civilization of the past 1,000 years.

The Mechanical Clock

Methods for keeping approximate track of time date from antiquity. Sundials, for example, were used by the ancient Egyptians. In the cloudier climates of Europe, however, sundials proved inadequate. Another ancient Egyptian invention was the water clock, in which water dripped from one reservoir into another at a relatively constant rate. The second reservoir contained a float attached to a pointer arm. As the float rose over the course of a day, the pointer indicated the approximate hour.

The first true mechanical clocks emerged in the 14th century in Europe. History gives no single person credit for the key invention that made these clocks possible: a mechanism called the verge escapement that uses a notched wheel powered by a weight or a pendulum and checked by a set of teeth. The teeth of the notched wheel “escape” at a regular interval, keeping the time. Early mechanical clocks had only hour hands—understandable considering that these timepieces were often off by as much as two hours a day. Subsequent refinements, such as the development of the pendulum based on a concept by Dutch astronomer Christiaan Huygens in 1657, made it possible to keep reasonably accurate track of minutes and seconds as well.

The achievement of artificial timekeeping has reverberated throughout civilization. It became an important part of navigation, as mariners relied on accurate time measurements to calculate longitude. It was a boon to science, as scientific observations often require accurate measurements of time. The same is true for many of the operations of business and industry, which require coordination of events and human activities. Today, an increasingly industrialized world is highly structured by time: Our clocks govern when we work, play, eat, and sleep.

The Glass Lens

Many of the scientific advances that have shaped the modern world were possible only because people devised tools to improve their ability to see. The development of glass lenses, which can be used to see things that are either very small or very far away, has had profound consequences for humanity.

The first application of ground, or polished, pieces of glass was not for the microscope or telescope, however. It was for spectacles (eyeglasses), which improve the vision of people with imperfect eyesight. It might be argued that without the invention of spectacles, printing would have taken much longer to catch on. Most people become farsighted as they age, and printed material held near the face dissolves into a blur. Without corrective lenses, reading becomes frustrating, if not impossible. The first spectacles were invented in Italy in the late 13th century, although crude versions may have been used in China several centuries earlier.

It took several hundred years before anyone assembled glass lenses in a way that made distant objects appear close. The credit for the invention of the telescope goes to Dutch optician Hans Lippershey. In 1608 Lippershey demonstrated his “looker” for the Dutch government, which immediately grasped its usefulness as a military tool. The next year, Italian physicist and astronomer Galileo used an improved version of Lippershey's invention to study the sky. Galileo's telescope could magnify things to 20 times their actual size. With this instrument he observed moons orbiting Jupiter, which contradicted the prevailing belief that all heavenly bodies revolved around the Earth. Galileo's observations helped initiate the scientific revolution that has fundamentally altered our world.

Early-17th-century Holland was a hotbed of optics development. It was here around the year 1600 that the microscope was invented, although sole credit for this achievement is difficult to determine. By 1625 optical workshops had been set up to build these new instruments, and in the late 1600s scientists were using microscopes to observe teeming microbes in a drop of water and the physical structure of living cells. These and other microscopic discoveries transformed biology. It was also during the 1600s that Dutch naturalist Antoni van Leeuwenhoek built his own microscope and discovered what he called animalcules, which are now known as bacteria and protozoa. Much of our knowledge of disease and how to fight it, including the concept of immunization, has flowed from the use of the microscope.

The Printing Press

Imagine a world without books, magazines, or newspapers. Until the 15th century, little imagination was required—few people knew how to read or write, and those that did had precious little to choose from in the way of reading material. For thousands of years the dissemination of knowledge was limited to word of mouth and laboriously handprinted, extremely costly manuscripts. The printing press provided a practical and inexpensive way to widely distribute information on a vast range of human activities, from literature to science to politics to religion. If any single invention can be said to have shaped the past millennium, it is the printing press. This machine ignited an era of artistic expression and scientific progress that continues today.

Some form of automated printing almost certainly predated AD 1000. The Chinese and Koreans had developed block printing, a technique in which raised letters and pictures are carved onto pieces of wood or other material. The surface is then coated with ink, and the image is transferred by rubbing or stamping. By the 2nd century AD the Chinese had developed a fairly widespread technique of printing texts. The Chinese are also credited with pioneering the art of papermaking at around the same time.

Printing in the Western world lagged behind. The bubonic plague, or 'Black Death,' that ravaged Europe in the 14th century, had severely depleted the continent of people who could read and write. There were so few scribes that copying books by hand became extremely expensive. At the same time, the widespread availability of linen resulted in a large supply of relatively inexpensive paper. The combination of these two factors helped create the economic conditions that fostered the development of mechanized printing.

It was the invention of movable metal type in the 1400s that proved the major breakthrough. Sometime around 1450, a German goldsmith named Johannes Gutenberg combined several key printing technologies. The most important was a method of creating uniformly shaped pieces of metal, each with a different letter of the alphabet on its face, that could be endlessly rearranged to form new text. Gutenberg also devised a hand-operated mechanical press able to push the type against the paper with sufficient force to guarantee high-quality pages of text. Gutenberg's first book was an edition of the Bible that still stands as a landmark of typographical elegance.

The printing press stoked intellectual fires at the end of the Middle Ages, helping usher in an era of enlightenment. This great cultural rebirth was inspired by widespread access to and appreciation for classical art and literature, and these translated into a renewed passion for artistic expression. Without the development of the printing press, the Renaissance may never have happened. Without inexpensive printing to make books available to a large portion of society, the son of John Shakespeare, a minor government official in rural England in the mid-1500s, may never have been inspired to write what are now recognized as some of history's greatest plays. What civilization gained from Gutenberg's invention is incalculable.

The Steam Engine

It is tempting to think of the car or the airplane as among the most important inventions of the millennium. But these were merely evolutionary refinements of the steam engine—the first machine to convert burning fuel into mechanical energy on a large scale. The first steam engines were powered by wood, and later ones by coal. Steam engines transformed the industrial world as few other technologies have. This invention liberated people from the limitations of their own muscles and those of beasts of burden. It made possible the factories that drove the Industrial Revolution. And it was at the heart of the first form of high-speed mechanized transportation: the locomotive.

The steam engine is a classic example of an invention that came about in stages. In 1698 English engineer Thomas Savery developed a water pump that used steam from a boiler for its power. Savery obtained a broad patent on the idea, even though his engine design never proved to be very useful. This was followed by a significantly more effective steam engine, built by English blacksmith Thomas Newcomen in 1712. Newcomen's device was also used primarily to pump water from coal mines. However, Scottish engineer James Watt is the individual most commonly cited as the inventor of the steam engine. His machine, patented in 1769, was vastly more efficient than were previous devices, chiefly because of its separate cooling chamber for condensed steam. Watt added other improvements, such as oil lubrication and insulation. He also designed a system of gears that translated the up-and-down motion of the steam-driven piston into rotary motion, which was more useful in driving machinery.

Watt's engine freed factories from their dependence on water power and gave a huge advantage to nations with ready supplies of coal. Britain's great reserves of coal fueled the expansion of the British Empire in the 18th and 19th centuries. Steam-powered railroad trains played a huge role in industrialization and trade and were vital to the westward expansion of the United States. Internal-combustion engines and electrical generating stations have since taken over most of the jobs once performed by steam, but these creations had to stand on the shoulders of the steam engine.

Electric Power

The modern world is an electrified world. It might be argued that any of a number of electrical appliances deserves a place on a list of the millennium's most significant inventions. The light bulb, in particular, profoundly changed human existence by illuminating the night and making it hospitable to a wide range of human activity. But the light bulb—and myriad other devices, from televisions and stereos to lasers to heart and lung machines—became useful only with the ready availability of centrally generated electrical power. It was not a single electrical device that changed the world so much as it was the system for generating and distributing the streams of electricity. In fact, although Thomas Edison is best known for his invention of the incandescent light bulb, his most important legacy was probably his founding of the electric power industry. Edison established the country's first large station for generating electric power in New York City in 1882.

The study of electricity dates from the early 1600s. In the mid-18th century, American statesman and scientist Benjamin Franklin conducted his celebrated experiments with electricity. During this time electricity for power was available only in limited quantities, from crude early batteries. The telegraph, for example, which debuted in the 1840s, ran on battery power.

The innovation that made electricity available in large quantities for human use was the dynamo, a machine that converted mechanical motion into electrical power. The dynamo is based on a discovery made by British scientist Michael Faraday in 1831. Faraday found that moving a coil of wire through a magnetic field produces an electric current in the wire. This allowed a straightforward conversion of steam, used to spin a rotor, into electricity. Once created, the electricity needed only a system of cables and transformers to carry it to the houses, factories, and office buildings that used it to power light bulbs and other electric appliances.

Access to cheap, reliable electric power at the flick of a switch has helped raise living standards around most of the world. To understand how important electricity is to everyday life, think of what happens when the power goes out in a storm. People fumble in the dark for flashlights and candles. Household appliances, including most computers and televisions, will not work. Food begins to thaw and spoil in useless refrigerators. Life grinds to a halt. When the power is restored, normal life resumes.

The Telegraph

For most of human history, messengers were the chief method of relaying information across long distances. The marathon in athletic contests is said to commemorate the time in ancient Greece when a messenger ran 42 km (26 mi) with the news of a great battle victory. According to the legend, the man collapsed and died just after delivering the good news. First horses and later the steam engine shortened the time that information spent in transit, but these were incremental improvements. Then came the telegraph, and the world has never been the same since.

The principle of telegraphy is simple: Pulses of electrical current are sent through a wire by manually tapping on a key to operate a simple switch. At the receiving end, the pulses create a magnetic field that causes a needle to punch holes in a strip of paper or that creates an audible click as a contact closes. When relayed in a coded fashion, these pulses can transmit a message, potentially over great distances.

In the 1830s and 1840s several scientists and tinkerers built telegraph prototypes. However, the technology did not take hold until an American painter and sculptor named Samuel F. B. Morse convinced the United States government to fund a telegraph line between Washington, D.C., and Baltimore, Maryland, in 1843. Morse also invented a system of dots and dashes—the code that now bears his name—to help standardize transmissions by wire. After the Washington-to-Baltimore line was completed in May 1844, Morse tapped out the first message: “What hath God wrought!” When the message was successfully received almost instantaneously 60 km (40 mi) away, the telecommunications revolution had begun.

Early telegraph operators soon found that the dots and dashes of Morse code could be distinguished by sound, and the paper tapes were discarded. A little more than 30 years later, Alexander Graham Bell came up with the telephone, a refinement that has become commonplace in modern society. More than a century of further improvements have brought high-speed communications of all types, including the Internet. But the telegraph shrank the world in one fell swoop in a way that no subsequent invention has matched.

Wireless Communications

If a person who lived in the year 1000 could somehow be transported to the year 2000, that person, no matter how awestruck, would still probably be able to grasp the principles behind many of the inventions described so far. However, the ability to send information through space, without wires or any other visible medium, might appear to be a form of black magic. Today's global web of communications depends on the ability to send signals long distances through space. The concept of broadcasting—sending a message to large numbers of people simultaneously—is possible only with radio waves.

Radio waves are a form of electromagnetic radiation, just like visible light, infrared light, ultraviolet light, and X rays. In 1888 Heinrich Hertz generated and detected the first known radio waves and proved that they travel at the speed of light. Because of the importance of this and other discoveries made by the German physicist, the term for cycles per second is known today as hertz (Hz).

It was Italian engineer Guglielmo Marconi who turned Hertz's laboratory experiments into a communications technology. After learning of Hertz's work in 1894, Marconi quickly realized the possible application. By the end of 1895 he had built a transmitter and receiver and had sent radio signals a distance of 2.5 km (1.5 mi). In 1901 he had improved the technology and was able to send a signal across the Atlantic Ocean.

Much of the public first learned about radio in the wake of a tragedy: When the luxury liner Titanic struck an iceberg in April 1912, the doomed ship used the new technology to desperately call for help. Only about 700 of the 2,220 passengers were rescued, but the number of survivors might have been much lower if other ships had not arrived when they did.

At first, radio functioned as a wireless telegraph, sending pulses of Morse code. Canadian-born American physicist Reginald Fessenden came up with a scheme for modulating radio waves, a technique that made it possible to transmit sound, and later, pictures. In 1906 he conducted the first radio broadcast. The first home television receiver was demonstrated in 1928. Wireless communication technologies have changed the world, bringing news and ideas to far-flung corners of the globe and influencing everything from fashion and language to the rise and fall of political systems.

Antibiotics

For most of human history, infectious diseases have killed people with brutal regularity. As recently as World War I (1914-1918) more battlefield deaths came from infection than from the direct trauma of gunshot. Physicians had very few weapons to combat cholera, pneumonia, meningitis, scarlet fever, gonorrhea, tuberculosis, or any of dozens of other diseases.

In 1896 French medical student Ernest Duchesne stumbled across a mold that seemed to kill bacteria. His discovery had little impact, however. Then, in 1928, Scottish researcher Alexander Fleming noticed that the presence of a certain mold in petri dishes stopped the growth of bacteria. He identified the mold as coming from the penicillium family and called it penicillin.

Fleming's achievement probably counts more as a discovery than it does as an invention—his penicillin was unstable and difficult to purify. Subsequent work by chemists Ernst Chain and Howard Florey at Oxford University in England resulted in techniques to culture the mold within a liquid held in huge vats. In late 1941 a wide-scale collaboration began among the U.S. government, industry, and academia to come up with a way to mass-produce penicillin. By 1944 manufacturers were able to make enough penicillin to treat all of the Allied soldiers wounded in the June 6 D-Day invasion of Europe during World War II.

The development of penicillin and the huge range of antibiotics that followed may have had a more profound effect on the health of humanity than any other in medical history. Within the space of a few decades following World War II, whole classes of once-fatal or life-threatening diseases became treatable. The development of antibiotics gave people an enormously effective shield against the scourge of disease.

The Transistor

What the steam engine was to the Industrial Revolution of the 18th and 19th centuries, the transistor was to the information revolution of the latter portion of the 20th century. Almost every piece of equipment that stores, transmits, displays, or manipulates information has at its core silicon chips filled with electronic circuitry. These chips each house many thousands or even millions of transistors.

Although the details are mind-bendingly complex, the transistor's basic function is simple: The device enables a small electrical voltage to control a flow of electric current. In computers, transistors act as tiny, speedy on-off switches. In the binary language of computing, these on and off states translate into the digital 1s and 0s that encode all manner of information—everything from letters of text to notes of music to colors in a photograph. It is this ability to reduce so rich a variety of information into such basic code that has made possible the explosion in information technology.

In one sense, the transistor does the same thing that an earlier technology, the vacuum tube, did. Vacuum tubes also use a small input voltage to control a flow of current, and they are therefore able to manipulate signals in the binary format that computers use. However, the computer revolution would have gone nowhere had the transistor not been developed to replace the bulky, unreliable vacuum tube. The first general-purpose digital computer weighed more than 30 tons and used some 19,000 vacuum tubes. Known as ENIAC, an acronym for Electronic Numerical Integrator and Computer, it was introduced to the public in 1946. ENIAC required huge amounts of power to operate, and the tubes frequently burned out or failed.

The transistor was invented in 1948 at Bell Telephone Laboratories by a team led by physicists John Bardeen, Walter Brattain, and William Shockley. At first, the computer was not high on the list of potential applications for this tiny device. This is not surprising—when the first computers were built in the 1940s and 1950s, few scientists saw in them the seeds of a technology that would in a few decades come to permeate almost every sphere of human life. Before the digital explosion, transistors were a vital part of improvements in existing analog systems, such as radios and stereos.

When it was placed in computers, however, the transistor became an integral part of the technology boom. They are also capable of being mass-produced by the millions on a sliver of silicon—the semiconductor chip. It is this almost boundless ability to integrate transistors onto chips that has fueled the information age. Today these chips are not just a part of computers. They are also important in devices as diverse as video cameras, cellular phones, copy machines, jumbo jets, modern automobiles, manufacturing equipment, electronic scoreboards, and video games. Without the transistor there would be no Internet and no space travel. Transistors are deeply embedded in the fabric of modern technology.

Inventing the Future

What a difference 1,000 years have made! In AD 1000 the world was a very different place. Most people spent their entire lives within a few miles of their birthplace. Communication was limited to a small circle of villagers and the occasional passer-through. Disease struck with dreadful regularity against a population that had almost no defenses. With the exception of a few priests and other elites, people were basically illiterate, and there was very little to read anyway. People in 1000 measured time by the Sun and the Moon. Scientific observation was limited to what could be seen with the naked eye.

Today, thanks to a millennium of scientific discovery and innovation, people's lives have been transformed. They can view events as they happen half a world away. They can pick up the phone and talk to a friend or relative in a foreign country in seconds. Motorized transportation, from cars to jets, allows people to travel long distances in short time periods. Electricity runs a vast array of labor-saving and entertainment devices. Newspapers and books are inexpensive and readily available. Life expectancy has greatly increased as medical science tracks down the causes and cures of more and more diseases. The desktop computer is a powerful tool for working, creating, and communicating.

This list of greatest inventions has focused exclusively on technological achievements. In a broader sense, humans have invented a great many other things over the past 1,000 years. One is modern democracy, with its assumption of basic human rights; another is symphonic music; still another might be baseball. Humankind's creative output spans a huge range of fields in addition to science and engineering—each with their own great developments and innovations during the last millennium.