Physicists' Finding Raises Relatively Huge Question: Was Einstein Wrong?

(Sept. 7) -- It's called the fine-structure constant, and physicists thought it would stay the same forever.

But a team at Australia's University of New South Wales suspect that this number, written into the very behavior of atoms, might actually change according to where you are in the universe, and when you are in time.

If these findings are valid, it could mean we have to rethink the laws of physics as we understand them.

It would also contradict Einstein's equivalence principle, a fundamental tenet of the general theory of relativity that says that certain values -- the fine-structure constant among them -- must remain the same no matter where or when in the universe they are observed.

The general theory of relativity lies at the basis of most of our models for explaining the way the universe works, so this is no small news.

The fine-structure constant: a primer

So what is the fine-structure constant? Put simply, it's a number that indicates the strength of the electromagnetic interaction -- how electrically charged particles, like protons and electrons, behave within the context of an atom.

If you wanted to calculate the fine-structure constant, you'd use an equation that plugs in a host of other values, including Planck's constant, the speed of light, the charge of an electron and pi.

Here, the units cancel each other out, and you're left with a dimensionless number equal to about 1/137.036 -- a number that, it was believed, would always stay the same no matter where you go in the universe.

But according to a team led by UNSW professor John Webb, that number seems to change depending on where you point your telescope.

The change, and what it means

Webb's team found that billions of years ago, the fine-structure constant appeared to have been smaller in one part of the universe -- and larger in another.

Though unexpected, the disparity seems to exist in accordance with a predictable pattern, and the team says that the odds are vanishingly small that what they're observing is just random variation.

The Australian team's findings need to be corroborated by further research, but they suggest that the fine-structure constant may have represented different values at other points in history, and in other sections of space.

In other words, what we think of as an immutable number may actually answer to an unknown set of influences.

As of yet, it's impossible to say what those influences might be. One suggestion, though, is that changes in unseen spatial dimensions -- which have long been a part of many physicists' models of existence -- may be affecting the physical constants here in our familiar three dimensions.

Whatever it means, the scientific community is paying close attention. Wim Ubachs, the head of the physics department at the Netherlands' Vrije Universiteit, has described the Australian team's findings as "the news of the year in physics."

It's enough to make you wish Einstein were still around.