A slight variation (1 714)

The implications of even a slight variation in alpha are many. The grand scale of some of these may explain why the John Templeton Foundation of Radnor, Penn., a spiritual organization with a goal of using new scientific discoveries to broaden theology, is in part supporting the research by Webb's team. On its Web site (http://www.templeton.org/), the foundation states that it takes particular interest in evidence that some unseen hand is molding the universe over time.

One of the most profound implications for science would be that the presumption of immutability for the laws of physics may be wrong. Although the universe is full of evidence of the constancy of these laws, the new finding suggests that "maybe there's a tiny violation of that," says Turner, a cosmologist.

On the other hand, it may not prove easy to distinguish a revision of the laws from merely a better understanding of parameters found in those laws.

As an example, Turner points out the accepted theoretical claim that elementary particles known as the W boson and the Z boson had no mass when the universe first exploded into being. Modern accelerator experiments have shown, however, that both are very massive today. Even so, physicists have not concluded that the laws of physics have changed. Instead, they envision that as the universe evolved according to the steady laws of physics, the inherent possibility for W and Z bosons to become massive was realized. Something similar may be behind the apparent discrepancy between ancient and modern values of alpha.

Taylor explains that the laws that describe the forces between charged particles, such as atomic nuclei and electrons, wouldn't necessarily change even if the values of alpha or other parameters do in fact vary. However, if alpha has enlarged in the past 12 billion years, the strength of that atom-binding force would have grown slightly. "I would take the view that, until we know better, the law might be universal but the values of these parameters may be time-dependent. It's hard to say," he adds.

String theory (1 637)

In the 1990s, the burgeoning branch of physics known as string theory fueled efforts to find variation in fundamental constants. In string theory, the fundamental particles of the universe are not points as they are in today's dominant theories. Instead they are vibrating, elongated stringlike entities. And, there are not just four dimensions—three spatial ones and time—but as many as 11 (SN: 2/19/00, p. 122: http://www.sciencenews.org/20000219/bob1.asp).

According to some string models, the values of certain constants are dependent on the scales of those extra dimensions. Although today those extra dimensions would remain tightly curled up and hidden on subatomic scales, some of them may have been more spread out shortly after the universe was born.

Although the string-theory models suggest that alpha variation would have taken place much earlier in the universe than 12 billion years ago, Webb's team may be seeing a "tail" remaining from a larger, earlier variation, Turner speculates. In any case, an ancient, slightly diminished alpha might be a sign that extra dimensions exist, and it might provide a coveted window onto their properties, says John D. Barrow of the University of Cambridge in England, a theorist on the varying-alpha team.

Complicating the interpretation of a once-smaller alpha, the quantity's magnitude relies on the values of other fundamental constants. Those are the size of the electron's charge, the speed of light, and Planck's constant, which defines the scales at which quantum phenomena operate.

A once-smaller alpha, therefore, could indicate that radiation may have zipped around slightly faster in the early universe than it does today, Webb says. As a result, interactions might have been possible between more widely separated regions in the early universe than in today's. That, in turn, might have affected the uniformity of the universe and some of its other properties, Webb adds.