Publisher: St. Martin's Press
Publication date: 5/22/2012
It is my task to convince you not to turn away because you don’t understand it. You see, my physics students don’t understand it either. That is because I don’t understand it. Nobody does.— Richard Phillips Feynman
The search for gravity waves can be compared to weather forecasting, writes popular science author Brian Clegg in a new book, Gravity: How the Weakest Force in the Universe Shaped Our Lives.
Both sciences rely on approximation rather than accurate prediction. Yet, weather forecasting is never considered a pointless endeavor.
While scientists cull through years of data analysis, an impatient public expects immediate results that justify the investment of millions of dollars.
“This doesn’t make the efforts of the gravity wave search totally worthless,” argues Clegg whose previous books include A Brief History of Infinity, Light Years, The God Effect and Before the Big Bang.
To be released in May, Gravity focuses on the countless theories, experiments and device technologies that have eluded attempts to realize a quantum theory of gravitation.
Clegg proposes there is no reason gravity should not be a quantum force, like electromagnetism and the strong and weak nuclear forces.
So, where does science look for further evidence?
“Gravity wave enthusiasts would like to follow Hubble and take a gravitational telescope into space.” Clegg writes of the project to develop the Laser Interferometer Space Antenna (LISA).
The isolation and controlled environment of space would prevent the distortions of air movement and pollution experienced by Earth-based interferometers. Currently in the proposal stage, the LISA project has become a hard sell in a worldwide recession.
Clegg starts the narrative of gravity as a very weak force by citing popular experiments.
Hold a small magnet near a refrigerator. Let go and the Earth’s mass will pull it downward, while magnetism will pull it toward the refrigerator. Which force wins? Certainly not gravity.
Strike a water molecule with a more powerful field from a magnet and the force repels the gravity field. Experiments with levitating frogs, which are light and have a high water content, are the stuff of antigravity science fiction.
And so is electromagnetism. Clegg remarks that this antigravity force is a real-world application of maglev trains. A strong magnetic field creates repulsion, which levitates the train above the track with no direct physical contact with the ground.
Despite the characteristic of gravity as a very weak force, Earthlings would never thrive in conditions of low gravity. Any long space journey would require some form of artificial gravity.
A spinning space station would generate the sensation of gravity toward the hull. Working against centrifugal force, the hull would stop the natural tendency of passengers rotating with the space station to shoot off sideways.
Clegg’s book reminds us of the simplicity of the physical law of gravity. He devotes a chapter to Newton’s amazing discovery and a chapter on Einstein’s theory of warped space-time.
According to Clegg, general relativity is for now the most effective way to make predictions about gravity that jibe with experiment.
The leap in thinking comes from accepting that time warped by a massive object makes passing through time also passing through space.
Gravity by Brian Clegg is a worthwhile read and a handy primer for learning the language of a quantum theory of gravitation.
Category: Nonfiction, Science