Matters of Gravity

Lee Smolin reviews Gravity’s Shadow: The Search for Gravitational Waves by Harry Collins, in American Scientist:

…despite the several billions invested in particle accelerators and detectors, there have been few truly major experimental discoveries in fundamental physics in the past 20 years. The fields that have continued to amaze are astronomy and cosmology, which are obviously healthy. But the only major addition to our knowledge of the elementary particles these past two decades was the discovery that neutrinos have mass. The list of new particles or effects that have been looked for—and so far not found—is longer: the Higgs particle, supersymmetric particles, dark-matter particles, proton decay, the fifth force, evidence of extra dimensions.

It is, then, very timely that Harry Collins has written a first-class study of how contemporary experimental physics operates. Collins is a distinguished sociologist, and in Gravity’s Shadow he demonstrates why it is important to go beyond superficial characterizations of science to study how groups of scientists actually work together and make decisions. Collins has taken as his subject the search for gravitational radiation.

Gravitational waves are ripples in the geometry of spacetime, analogous to electromagnetic waves. Just as moving charges and magnets produce light waves, masses when they accelerate inevitably produce waves in the gravitational field—a field that, as Einstein discovered in working out his theory of general relativity, is exactly the same as the geometry of space and time.

More here.