杏吧原创

IN this era of global upheaval, we all need as much certainty as possible.
Take the laws of physics. While nobody thought we had it licked, what we did
know looked solid enough. Now, suddenly, that ground may be about to give
way.

At first glance, it doesn鈥檛 sound that serious鈥攐ne of the numbers which
determines the nature of the Universe may have been very slightly different from
its present value billions of years ago
(see p 12). It is, in fact, a bombshell.
Everyone is in a state of disarray, from the Nobel prizewinners who call it
鈥渞evolutionary鈥� to the rank and file physicist who just knows it could be Very
Important.

The number in question鈥攖he fine structure constant鈥攃ontrols the
interaction between light and matter. That means it controls essentially
everything in the everyday world from the combustion of petrol to the stiffness
of steel, from soap bubbles to the solidity of tables and chairs.

As its name suggests, the number is supposed to remain fixed at one value
throughout space-time. If it does vary, we will need to rethink fundamental
ideas about how the Universe evolved鈥攁nd possibly even about how our world
works.

Of course, the claim may be wrong. The variation that has been measured
amounts to only a few parts in 100 000. There is always the chance鈥攁s the
researchers admit鈥攐f some kind of instrumental error. And to be honest,
physicists鈥� track record on 鈥渞evolutionary鈥� findings has been pretty abysmal of
late. Last April, we heard about 鈥渆mpty space twisting the path of
light鈥濃�攚hich turned out to be based on a statistical mirage. Even more
remarkable was the 鈥渄iscovery鈥�, last March, of a previously unknown 鈥渇ifth鈥�
force of nature鈥攁 finding that has never been confirmed. And before that
there was a widely reported false alarm about the discovery of particles more
fundamental than quarks.

What these events are telling us is that physicists have reached an an
exciting crossroads. They are desperately seeking a bigger, more comprehensive
picture of the Universe, and are prepared to entertain ever wilder ideas to find
the missing pieces.

We shouldn鈥檛 judge them too harshly. Surely discoveries that do not fit the
prevailing world view are the lifeblood of science.

A variation in the fine structure constant is as inexplicable in terms of any
current theory as radioactivity was to the classical physics of the late 19th
century. But we should remember that radioactivity led to lasers and an
explanation of sunlight. Even more importantly, it led to a new quantum physics
which fundamentally changed our view of reality.

Who knows what kind of revolution might be born if, and it is a big if, a
variation of the fine structure constant turns out to be real.