Einstein’s revolution enters second century

Just after the turn of the century, scientists knew that their fundamental theories weren't quite right — they just didn't know what to do about it.

If we're talking about what happened a century ago, this is where Albert Einstein came to the rescue. During the "miracle year" of 1905, he published five groundbreaking scientific papers that are still sparking innovations 100 years later.

But we could as well be talking about what's happening right now. Over the past decade, physicists have come to appreciate, to an even greater degree than in Einstein's day, just how little they know about how the cosmos works. The latest observations indicate that 95 percent of the universe consists of stuff we don't understand:

• Dark matter, which can only be detected through its gravitational effect, makes up about 25 percent.
• Dark energy, a property of empty space that seems to be pushing galaxies farther apart at an increasing rate, accounts for the other 70 percent.

"In a sense, it's the ultimate Copernican revolution," says Sean Carroll, a physicist at the University of Chicago. "Not only are we not at the center of the universe — we're not even made of the same stuff as most of the universe is made of."

The current knowledge gap presents "an amazing parallel" between 1905 and 2005, says John Rigden, a physicist at the Washington University of St. Louis who wrote the book "Einstein 1905."

"In 1905, if a person put their hand on top of their desk, they had no idea what their hand was contacting," Rigden says. "In other words, the nature of matter was unknown. Atoms were speculated about, and many people believed in them in 1905, but other people did not.

"Now, today, if you put your hand on top of your desk, you know what your hand is contacting — but that type of matter makes up only about 5 percent of the universe," he says. "One hundred years have passed, and we're still 95 percent ignorant about the material world. I find that amazing."

Seeking a 'theory of everything'
As if that weren't enough to chew on, physicists are still trying to do what Einstein could not: bridge the two grand pillars of modern physics, relativity and quantum mechanics, with a unifying "theory of everything" that could explain phenomena ranging from the Big Bang to the ultimate fate of the universe.

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Some theorists say it could be done, if we could just add a few extra dimensions to the ones we perceive. Others, however, suspect that the effort might be fruitless.

"There's a huge, almost unanimous view that this is a fundamental problem, to unify these two things," says physicist Freeman Dyson, who like Einstein gravitated to the Institute for Advanced Study in Princeton, N.J. "My belief is that it very well may be that God didn't intend that."

So, as the world marks the centennial of Einstein's miracle year — and the 50th anniversary of his death on April 18, 1955 — legions of physicists are trying to extend the path of Einstein's genius, and sometimes leaving that path to blaze their own trail.

If the coming decades follow the model set by Einstein's miracle year, the effects won't be felt only in abstruse physics textbooks: Looking back at the past century, you can see the results of Einstein's theories in innovations ranging from the atom bomb to the microwave oven.

And it all started with a 16-year-old's daydream.

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