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What does the last line of the abstract refer to, about "deviations from general relativity"? Is it simply a statement that this (and other) observations of gra

What does the last line of the abstract refer to, about "deviations from general relativity"? Is it simply a statement that this (and other) observations of gravity waves are another tool for verifying GR's predictions?

jlebar 10y ago
> Is it simply a statement that this (and other) observations of gravity waves are another tool for verifying GR's predictions? That is how I read it, yes.
ISL 10y ago
Yes. These gravitational wave detections are the only direct measurements anyone's ever made in regions of such strong gravity. If strong-field gravity betrays any failing of the theory of GR, we'd expect to find it in gravitational-wave waveforms. That these waveforms (the first one, in particular) appear to follow the basic GR plan at the time of the merger is actually kind of a bummer. As a physicist who makes precision tests of gravity for a living, I'd really hoped that we'd see something unexpected. Instead, the new thing that we learned is that GR continues to be an accurate model, something that was perhaps unexpected on its own.
- eaq 10y ago
  I'm not so surprised that there are no GR deviations in these early days of detections that are just becoming significant over the instrument noise. GW physicists are hard at work on the future generations of GW detectors... In 50 years, a signal like GW150914 might have an SNR of >1000, so we'll see all kinds of detail that may hold more information than what we've seen so far.
  - ISL 10y ago
    People have been testing GR really hard for a century, especially in the last fifty years. Nobody's convincingly found a single chink in the armor. Clifford Will's "The Confrontation between General Relativity and Experiment" is an excellent introduction to the state of the art (this is the stock reference for everyone in the field). http://relativity.livingreviews.org/Articles/lrr-2014-4/ http://relativity.livingreviews.org/Articles/lrr-2014-4/

jlebar 10y ago

> Is it simply a statement that this (and other) observations of gravity waves are another tool for verifying GR's predictions? That is how I read it, yes.

ISL 10y ago

Yes. These gravitational wave detections are the only direct measurements anyone's ever made in regions of such strong gravity. If strong-field gravity betrays any failing of the theory of GR, we'd expect to find it in gravitational-wave waveforms. That these waveforms (the first one, in particular) appear to follow the basic GR plan at the time of the merger is actually kind of a bummer. As a physicist who makes precision tests of gravity for a living, I'd really hoped that we'd see something unexpected. Instead, the new thing that we learned is that GR continues to be an accurate model, something that was perhaps unexpected on its own.

eaq 10y ago
I'm not so surprised that there are no GR deviations in these early days of detections that are just becoming significant over the instrument noise. GW physicists are hard at work on the future generations of GW detectors... In 50 years, a signal like GW150914 might have an SNR of >1000, so we'll see all kinds of detail that may hold more information than what we've seen so far.
- ISL 10y ago
  People have been testing GR really hard for a century, especially in the last fifty years. Nobody's convincingly found a single chink in the armor. Clifford Will's "The Confrontation between General Relativity and Experiment" is an excellent introduction to the state of the art (this is the stock reference for everyone in the field). http://relativity.livingreviews.org/Articles/lrr-2014-4/ http://relativity.livingreviews.org/Articles/lrr-2014-4/