Lab Tuned to Gravity's 'Ripples' 173
Krishna Dagli writes "One of the great scientific experiments of our age is now fully underway. Success would confirm fundamental physical theories and open a new window on the Universe, enabling scientists to probe the moment of creation itself. The experiment is trying to detect ripples created in the fabric of space-time that sweep out from merging black holes or exploding stars and detection would be a final test of Albert Einstein's General Theory of Relativity. "
Re:negative outcomes? (Score:3, Insightful)
If the research doesn't pan out, then we will move on and create new hypothesis. You can only throw so much money at one thing at a time. If we fail, we redo.
just imagine the possibilities. Flying car anyone?
Baz
Re:negative outcomes? (Score:5, Insightful)
Re:negative outcomes? (Score:5, Insightful)
Is it? If I remember correctly the lack of an alternate hypothesis when Michelson and Morley failed to detect the aether caused Einstein to beging pondering special relativity.
Re:negative outcomes? (Score:3, Insightful)
But seriously - if things all point to a likely model, and nothing (rationally) points to an alternative, why kill yourself (and your budget) documenting hollow alternatives just so that you're sticking to academic form?
Re:negative outcomes? (Score:1, Insightful)
Will they measure the speed of gravity as well? (Score:3, Insightful)
It is important that we find what gravity is, because if it is a wave of particles, then maybe there is a possibility to find a way to shield gravity away. Shielding gravity would be a major step towards space exploration.
Re:negative outcomes? (Score:3, Insightful)
There are already alternative theories, such as bosons named gravitons. That might just be a variation in interpretation of wave-particle duality, but since quantum gravity isn't the same thing as general relativity it passes muster. There are other gravitational alternatives proposed, usually flawed and/or not well accepted by the scientific community. And what impact this experiment wil have on the Higgs particle question, one way or another?
Your post seems to imply this is an all or nothing experiment. But GR wouldn't be challenged only by a null result. If the magnitude of any detected gravity waves is significantly different from expectations, the discrepancy will have to be explained. Often, these differences are more challenging to a theory. Unexpected behavior of a newly detected but predicted phenomena is also a major challenge to existing theories. I can't wait to see what kind of information can be obtained by some analog of Zeeman splitting in gravity wave spectroscopy, if such a thing exists. That will be far more revealing than any "Yup, that's a gravity wave" result.
Re:negative outcomes? (Score:1, Insightful)
Your thought experiment proves nothing. GR predicts that a "cup of neutrinos" will oscillate back and forth; it also unambiguously predicts that gravitational waves are transverse. Therefore, neutrinos oscillating back and forth is not proof that gravitational waves must be longitudinal; a counterexample exists.
More directly: your thought experiment has nothing to do with gravitational waves, it is only sensitive to static gravitational fields. Of course objects will accelerate in the direction of the gravitational field. This has nothing to do with whether the waves are parallel or perpendicular to their direction of propagation.
Note that if you did the same experiment with a test charge and a uniformly charged ball, you'd get simple harmonic motion, but electromagnetic waves are provably transverse: another flaw in your logic.
Re:let me be more precise (Score:3, Insightful)
As to how many billions of dollars it takes - quite a lot. But the practical outcomes I've listed are what you get. Along with international co-operation - many countries working together for a common goal.
And another thing. It's gravitational wave detection. Not gravity wave detection, which is something completely different.
Large scale experiments are what research is all about. There comes a point in research where a table-top experiment just won't do.