via Scientific American on 11/24/09
Was Newton right and Einstein wrong? It seems that unzipping the fabric of spacetime and harking back to 19th-century notions of time could lead to a theory of quantum gravity.
Physicists have struggled to marry quantum mechanics with gravity for decades. In contrast, the other forces of nature have obediently fallen into line. For instance, the electromagnetic force can be described quantum-mechanically by the motion of photons. Try and work out the gravitational force between two objects in terms of a quantum graviton, however, and you quickly run into trouble--the answer to every calculation is infinity. But now Petr Ho ava, a physicist at the University of California, Berkeley, thinks he understands the problem. It’s all, he says, a matter of time.
[More]
Physicists have struggled to marry quantum mechanics with gravity for decades. In contrast, the other forces of nature have obediently fallen into line. For instance, the electromagnetic force can be described quantum-mechanically by the motion of photons. Try and work out the gravitational force between two objects in terms of a quantum graviton, however, and you quickly run into trouble--the answer to every calculation is infinity. But now Petr Ho ava, a physicist at the University of California, Berkeley, thinks he understands the problem. It’s all, he says, a matter of time.
[More]
No comments:
Post a Comment