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No wonder these waves are so hard to detect.
Ed Seidel, NCSA/Univ. of Illinois, on-camera
QuickTime Movie (1.0 MB); Sound File (615K); Text
Eddington was not the only skeptic. Many physicists thought the waves predicted by the theory were simply a mathematical artifact. Yet others continued to further develop and test the concept. By the 1960s, theorists had showed that if an object emits gravitational waves, its mass should decrease. Then, in the mid 1970s, American researchers observed a binary pulsar system (named PSR1913+16) that was thought to consist of two neutron stars orbiting each other closely and rapidly. Radio pulses from one of the stars showed that its orbital period decreases by 75 microseconds per year. In other words, the stars are spiralling in towards each other -- and by just the amount predicted if the system were losing energy by radiating gravity waves.
Aside from demonstrating the existence of black holes and revealing a wealth of data on supernovae and neutron stars, gravitational wave observations could also provide an independent means of estimating cosmological distances and help further our understanding of how the universe came to be the way it looks today and of its ultimate fate. Gravitational waves might unveil phenomena never considered before. Nature is smarter than any theorist trying to imagine or calculate what might be out there!
Consider the waves emitted by a single, distorted black hole, for example.
Distorted Black Hole
The remarkable thing about a black hole when simulated on a computer is that no matter how it forms
or is perturbed, whether by infalling matter, by gravitional waves, or via a collision with another object
(including a second black hole), it will "ring" with a unique frequency known as its natural mode
of vibration. It's this unique wave signature that will allow scientists to know if they've really detected
a black hole. But that's not all. The signal will tell them how big the black hole is and how fast it's spinning.
to LIGO: A New Window on the Universe
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