Examining Gravity Waves

Joseph "JoeDaMac" Haake writes "Sometime within the next two years, researchers will detect the first signals of gravity waves -- those weak blips from the far edges of the universe passing through our bodies every second. Predicted by Einstein's theory of general relativity, gravity waves are expected to reveal, ultimately, previously unattainable mysteries of the universe."

Comments

Bit optimistic

[Anonymous Coward]

"Researchers WILL detect..."

On the whole, i think that's not necessarily true. There are several mathematically consistent fringe quantum-physical theorys (usually something akin to higher-order-symmetry electrodynamics) in whcih gravity waves are indistinguishable from e.m. waves, or are longitudinal-time e.m. waves.

Re:rigged model matching?

[radtea]

Scientists are extremely uptight about exact numerical analysis. We get the data and compare them to a tightly parameterized model which includes everything we know about our detector response as well as the probable sources of the events we are detecting. Good models have small numbers of parameters and many constraints compared to the richness of the data. "With enough free parameters you can fit an elephant", the saying goes, which indicates how important it is to scientists to keep the number of parameters small--no one wants to see a comment like that on a referee's report!

With regard to gravitational observatories, the data are very rich: polarization, amplitude, phase and frequency spectra will be available, possibly from several detectors with different orientations. Detector response is also extremely well understood. The theoretical physics of the sources--general relativity--is also very well understood, and models of stellar collapse, neutron star collisions, etc, contain few parameters (masses, angular momenta, impact parameter...that's about it.)

As such, we can compare model to reality and produce a statistically valid likelihood that the model is false. The Baysians in the audience will point out that relative to our prior knowledge we can also produce the probability that the model is true.

So it isn't a matter of getting something that "roughly fits"--the analysis either produces a fit within error or it does not. If it does not, we dig more deeply into the possible sources of disagreement. The data are sufficienty rich that many, many types of cross-checking and internal consistency checking will be available.

To a hardened skeptic, this of course will not do. But hardened skepticism is an anti-scientific attitude. Scientists are open-minded skeptics, who are able to keep the contingent nature of their beliefs in mind while at the same time maintaining a commitment to distinguish clearly between probable truth and probable falsehood.

--Tom