The name of Albert Einstein is synonymous with intellectual power, which explains why he heads the list of the 20 most influential thinkers of the past 100 years.
People as diverse as Ludwig Wittgenstein, the Austrian philosopher, William Shockley, the inventor of the transistor, and Sigmund Freud, the pioneer of psychoanalysis, are among the famous names listed by Time magazine as this century's greatest brains.
The 20th century, Time says, "overthrew our inherited ideas about logic, language, learning, mathematics, economics and even space and time. And behind each of these great inventions is, in most cases, one extraordinary human mind."
Britain is well represented in the list, with seven names among the top 20, including Alexander Fleming, the discoverer of antibiotics, John Maynard Keynes, the influential economist, and Alan Turing, the tortured mathematician and computer scientist.
But it was Einstein who dominated the 20th century with his two theories of relativity. He published his first, "special" theory in 1905 while he was still a patent office clerk, and his more important, "general" theory in 1916.
James Gleick, the science author, writes in Time that the scientific touchstones of the age - the nuclear bomb, space travel and electronics - all bear Einstein's fingerprints. "He discovered, just by thinking about it, the essential structure of the cosmos," he says.
Sir Martin Rees, Britain's Astronomer Royal, agreed with Time that Einstein dominated the scientific achievements of the 20th century, notably with his general theory of relativity, which explains the relationship between gravity and space.
"If he hadn't come up with his general theory, it might not have been described for several more years. Einstein put a more distinctive mark on science," Sir Martin said.
Many discoveries came about as a result of good luck and "people who made the greatest discovery don't always have the greatest intellect", he said.
Alexander Fleming's discovery of penicillin, made after an accidental contamination in his laboratory, is a prime example of a lucky accident leading to a major breakthrough.
Francis Crick and Jim Watson, the two Cambridge scientists who discovered the double helix structure of DNA, did what others would have done a few years later, said Lewis Wolpert, professor of biology as applied to medicine at University College London.
But being first matters, which is why Crick and Watson achieve a place in Time's hall of fame as the co-discoverers of the "secret of life" in 1953.
"Not until decades later, in the age of genetic engineering, would the Promethean power unleashed that day become vivid," the magazine says, referring to late-20th-century developments in biotechnology.
Men dominate Time's list of great thinkers, which includes technology intellectuals such as Tim Berners-Lee, the architect of the Internet, and Wilbur and Orville Wright, the pioneers of powered flight.
But one woman stands out: Rachel Carson, an American biologist, is credited with virtually inventing the environmental movement with her book Silent Spring, which alerted the world to the dangers of pesticides.
"Silent Spring, serialised in The New Yorker in June 1962, gored corporate oxen all over the country," Time says.
Not surprisingly, Carson was violently assailed by threats of legal action from some of the biggest companies in the United States, including Monsanto, the agrochemicals giant.
"In their ugly campaign to reduce a brave scientist's protests to a matter of public relations, the chemical interests had only increased public awareness. Silent Spring became a runaway best-seller, with international reverberations. Nearly 40 years later, it is still the cornerstone of the new environmentalism," says Time magazine.
Patent office clerk who became the century's most influential scientist. At 26, developed theory of relativity, basis for advances in quantum physics, space travel and electronics.
The father of psychoanalysis. Credited with opening the door to our unconscious selves. Concepts such as ego, repression and penis envy spring from his work.
Bacteriologist who invented penicillin, world's most effective lifesaver and key to all antibiotics. Found when an experiment was accidentally contaminated.
Atomic physicist who helped pioneer nuclear fission. Co-inventor and designer of the first nuclear reactor. Hailed as last great physicist to excel both at theory and experimentation.
WILBUR AND ORVILLE WRIGHT
Brothers Wilbur and Orville (above) were bicycle mechanics who made first powered human flight in 1903. Ultimately responsible for the aviation age.
Computer scientist who built the world's first calculating machines and laid the groundwork for all computer technology. Committed suicide after prosecution for homosexuality.
Virologist who invented the polio vaccine in the Fifties after two epidemics which crippled thousands of children. Suffered from in-fighting in US scientific establishment.
Pioneering philosopher who started out trying to "end philosophy" in 1922 by elegantly codifying all thought in terms of logic. Eventually questioned all original ideas.
JAMES WATSON AND FRANCIS CRICK
Molecular biologists Watson (above) and Crick discovered DNA's double helix, basis of life. Fought opinion in developing theories ranging from crime-fighting to philosophy.
Solid-state physicist and inventor of the transistor, which made computer technology possible. Held radical racial view that black people were inherently less intelligent than whites.
Belgian-born chemist who invented the first synthetic plastic - Bakelite. It was discovered in 1909 during his search for an insulating material for the growing electric industry.
British computer network designer who originated the World Wide Web. Credited with the huge growth of the Internet - 600,000 to 40 million users from its launch in 1991 to 1996.
Marine biologist who wrote Silent Spring in 1962, forerunner of environmental movement. Listed effects of pesticides on wildlife, despite attack by US chemical companies
JOHN MAYNARD KEYNES
Economist thought of as father of modern economics. Theories on pulling economies out of depression by increasing demand credited with saving capitalism.
Astronomer who formulated theory of Big Bang in 1920s, realising universe beyond the Milky Way was expanding. Einstein said Hubble's contribution helped prove his theories.
Author of arguably the most important discovery of 20th-century mathematics. His "incompleteness theorem", of 1931, proved wrong nearly 100 years of mathematical research.
Rocket scientist who pioneered the technology in the 1930s amid ridicule. Nazis used ideas to produce V2 rockets for attacking London, but rockets did put a man on the moon.
THE LEAKEY FAMILY
British family of pioneering anthropologists - Louis, Mary and son Richard (above) - whose work in Kenya revolutionised the understanding of human evolution.
Child psychologist who developed the theory that children were not empty vessels to be filled with knowledge but had their own logic with which they constructed their world.
Inventor of the TV tube, after the ideacame to him at 14. Died in obscurity. "There's nothing on it. We're not watching it in this house," he told his son.