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Curious4Ever
Jun26-11, 01:43 PM
While letting the TV series, 'Through the Wormhole', drone on in the background today, I was reminded of a puzzlement that's been itching in the back of my head for decades.

Through the Wormhole is light on details, but a smorgasbord of interesting concepts, many of which involve gravity. Nearly all physicists and cosmologists refer to gravity as either a force or field. I always thought it was an effect.

Didn't Einstein define gravity as an effect caused by mass warping space-time? So would not the search for gravitons, or the gravitational field, be as futile as looking for the little gray particles that makeup a shadow?

Was Einstein wrong, or have I misunderstood him all these years?

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bcrowell
Jun26-11, 02:29 PM
Didn't Einstein define gravity as an effect caused by mass warping space-time? So would not the search for gravitons, or the gravitational field, be as futile as looking for the little gray particles that makeup a shadow?

Every other interaction, such as electromagnetism, is known to be both a field (wave) and a particle. GR is a field theory, with the field being interpreted as curvature of spacetime. (It's different from the 9.8 m/s2 gravitational field of Newtonian mechanics, though.) There are fundamental reasons why you can't get a consistent theory by coupling a classical field (with no quantum-mechanical particle properties) to a quantum mechanical field (with particle properties).