Albert Einstein, in 1905, when he published his relativity, to bring chaos in the world of Physics. 

Clear your misconceptions about Dr. Albert Einstein.

We've come to think of Albert Einstein as the white-haired genius with sagging eyes who dressed casually and needed a haircut.

But that aging icon was decades past his prime, spinning his wheels on a grand theory that didn't pan out.

The Einstein who revolutionized our understanding of the universe was a nattily dressed young man with unlined skin, a trim mustache and dark, neatly cropped hair.
In 1905, when Einstein was an unknown, 26-year-old patent clerk, he published three theories of breathtaking brilliance, including his mind-bending special theory of relativity.
Physicists call it Annus Mirabilis, the Miraculous Year.

To mark the centennial of Annus Mirabilis, the United Nations has declared 2005 the World Year of Physics. There has also been an outpouring of Einstein-related school projects, poster competitions, lectures, books, exhibits, documentaries and blogs.

The Illinois Humanities Council, for example, is sponsoring a series of five Einstein lectures. The first lecture last month was standing room only, and people had to be turned away. "The response has been unbelievable," a spokeswoman said.

Free time to pursue science
Albert Einstein was born in 1879 to a middle-class family of German Jews. His parents initially worried that Einstein might be retarded because he barely spoke before age 3. Contrary to mythology, Einstein got good grades in elementary school -- though he chafed at the rote learning. He went to high school and college in Switzerland, where he found the progressive schools more to his liking.

The greatest scientist of the 20th century began his career as a bureaucrat. After graduating from the Swiss Polytechnical Institute, Einstein tutored for two years before finding a full-time job as a low-level technical expert with the Swiss patent office.
Fortunately, the job left him enough free time to pursue science. Einstein made notes that he kept in a drawer he jokingly called his department of theoretical physics.
During his miraculous year, Einstein published a series of papers in the prestigious journal Annalen der Physik (Annals of Physics). Einstein biographers Michael White and John Gribbin have written that Einstein's achievements were especially impressive, considering he didn't yet have a doctorate, couldn't get even lowly academic jobs and was "totally isolated from the rest of the scientific community."

March 1905. Miracle One: Light. The prevailing theory held that light traveled in smooth waves. Einstein showed that light behaves not only like waves but also like a stream of particles -- now called photons. He later won a Nobel Prize for this work.

May 1905. Miracle Two: Atoms. Einstein provided new insight into the theory that heat is caused by the agitated motion of atoms, called Brownian motion. Einstein offered mathematical proof of the existence of molecules. This finding alone "would have earned Einstein a place in history," physicist Roger Penrose writes in Einstein's Miraculous Year.

June 1905. Miracle Three: Relativity. One hundred years later, the theory's predictions still startle.
Einstein showed that the speed of light in a vacuum -- 186,282 miles per second -- is absolute and unchanging, regardless of the observer's position. But time, mass and length are relative.
We don't notice relativity in our everyday world. But relativistic effects become much more pronounced at speeds approaching the velocity of light.

Speed of light
Say, for example, you are on a spaceship traveling at 75 percent the speed of light, and another spaceship shoots by in the opposite direction at 75 percent the speed of light. You might guess that the other ship would recede from you at 150 percent the speed of light. But as Einstein showed, nothing goes faster than light. According to relativity theory, the two ships will recede from each other at 96 percent the speed of light.

Relative to a stationary observer, as an object approaches the speed of light, its time slows and it shrinks in size, as its mass increases. If a spaceship traveled at 99 percent the speed of light, for example, it would appear to a stationary observer to contract to one-seventh its length. Similarly, one hour on a spaceship clock would equal seven hours on a stationary clock.

A 70-pound baseball
Say you left earth on a five-year. round-trip journey, traveling at 99 percent the speed of light. When you got back, you would be five years older, while folks on Earth would have aged 36 years.

Another effect: Mass increases as an object speeds up. If you threw a 5-ounce baseball at 99.999 percent the speed of light, it would weigh 70 pounds.
This all may seem hard to believe, but time and again, sophisticated scientific experiments have confirmed relativity theory. In one such test, an extremely accurate clock flown on a fast jet was compared with a synchronized clock on the ground. Just as Einstein predicted, a tiny bit less time elapsed on the jet's clock.

In 1916, Einstein broadened his theory to include gravity. According to this new general theory of relativity, gravity from a massive body such as the sun warps space.
Therefore, light should curve as it passes through the warped region of space near the sun. In 1919, British astronomer Arthur Eddington tested this prediction by observing starlight during a solar eclipse, when stars are briefly visible.

Just as Einstein predicted, starlight curved as it passed the sun. Overnight, this dramatic confirmation of general relativity turned Einstein into a worldwide celebrity.
Einstein was never one for small thoughts. He spent his last decades working on his "unified field theory" -- an ambitious attempt to tie together the forces of gravity and electromagnetism.
It didn't work out, and Einstein's futile quest left him isolated from most physicists. As he wrote to a friend, "I have become a lonely old chap who is mainly known because he doesn't wear socks and who is exhibited as a curiosity on special occasions."

Understanding came in '70s
Maybe he was just ahead of his time. "Physics wasn't ready," said physicist Jessica Clark of the American Physical Society. "We didn't have the tools."
If Einstein had never lived, someone else almost certainly would have discovered relativity, physicists today say. But it would have taken another 10 or 20 years.
It wasn't until the 1970s that physicists understood all of the nuances of relativity.
It turns out the theory isn't perfect. For example, relativity is not fully consistent with the well-established quantum theory that describes the structure and forces of subatomic matter.

There also are several cosmic questions relativity can't answer, said University of Chicago cosmologist Michael Turner:

*What happened before the universe began with a Big Bang?

*What is the ultimate fate of the universe? Will it keep expanding until the stars burn out -- the Big Chill? Will it collapse in on itself -- the Big Crunch? Or will it collapse and then bounce back in another Big Bang?

*What's at the center of a black hole? If you fall into a black hole, would you come out in another part of the universe, or even in another universe altogether?
Picking up where Einstein left off, physicists are trying to tie together the fundamental forces of nature into what they now call the Theory of Everything.

"We have digested what he did and are ready to move on," Turner said. "We're poised for another revolution."

Simple formula explains atom bombs -- and the sun
After publishing his special theory of relativity, Albert Einstein submitted a three-page follow-up paper containing the most famous equation in science, E=mc2.
Energy (E) equals mass (m) times the speed of light squared. In other words, energy and mass are different forms of the same thing. It's why we have atom bombs, nuclear energy and smoke detectors.

The equation says you can turn mass into energy and vice versa. Notice that mass is multiplied by a very large number, the speed of light squared. Because of this multiplier effect, a small amount of mass can be converted into a large amount of energy.

It happens every day in a nuclear power plant. Each time an atom of uranium fuel splits apart in the reactor, about 0.1 percent of its mass is converted into heat energy.

The same thing happens in a nuclear bomb, and in the center of the sun. Every second, the sun's nuclear furnace turns 4 million tons of hydrogen into pure energy.

A small amount of mass also is turned into energy during radioactive decay. This has practical applications as varied as smoke detectors, red-glowing exit signs and medical tests such as PET scans, often used to detect cancer

Newton laid the groundwork in 1660s
As great a year as Albert Einstein had in 1905, it probably falls short of what Sir Isaac Newton accomplished from 1665 to 1667.

In 18 months, the English scientist showed how the universe is held together with gravity, explained the optics of light and color and invented calculus, an entire new branch of mathematics.

Einstein relied on others for the math he used in deriving his theories. By contrast, when Newton needed new math for his work, he invented calculus. (Calculus was independently discovered by German scholar G.W. Leibniz.)

"Newton easily is the best physicist, and arguably the best mathematician of all time," said University of Chicago physicist Sean Carroll.

Einstein himself acknowledged Newton's greatness. He said his work would have been impossible without Newton, whose concepts "are even today still guiding our thinking in physics."