First off I would like thank you all for responding.

If we could percieve gravitational waves(?), and the sensors that we
now use as has been mentioned of LIGO LISA, GRACE and others, can we
mathematically "re-constitue in numerical relativity computationally",
the structural failures over these vast distances accurately? Evidence
of supernovas, blackholes, gravitational collapses?

Sol

sol:
First off I would like thank you all for responding.

If we could percieve gravitational waves(?), and the sensors that we
now use as has been mentioned of LIGO LISA, GRACE and others, can we
mathematically "re-constitue in numerical relativity computationally",
the structural failures over these vast distances accurately? Evidence
of supernovas, blackholes, gravitational collapses?

If I understand you correctly, the answer is yes, in principle. In
practice, that won't happen any time soon. Gravitational detectors are
just telescopes for gravitational radiation, but by comparison to optical
or radio telescopes, LIGO, etc., are rather crude when it comes to
resolving power.

sol wrote:

First off I would like thank you all for responding.

If we could percieve gravitational waves(?), and the sensors that we
now use as has been mentioned of LIGO LISA, GRACE and others, can we
mathematically "re-constitue in numerical relativity computationally",
the structural failures over these vast distances accurately? Evidence
of supernovas, blackholes, gravitational collapses?

Sol

In principle, yes. In practise, absolutely not. There are all sorts of
terribly subtle issues with formulating general relativity as an initial
value problem/Cauchy problem suitable for computational work that jump
up and bite you in the ass. Most 3+1 decompositions of spacetime are
just rubbish once you try to evolve non-trivial spacetimes. For example,
the standard ADM equations, when used as a basis for numerical
simulations of a binary black hole spacetime, seem to be *highly*
sensitive to your choice of gauge, with most dying after about 60M (M
being a black hole mass).

There's obviously something very deep going on in the mathematics of
general relativity that we don't understand yet. The most promising
candidates for simulating events that will produce detectable
gravitational waves (for example, binary black hole coalescence;
inspiralling binary neutron stars; grazing black hole collisions) are
being produced using modified BSSN formulations or Jim York's
first-order symmetric hyperbolic work.

I don't have the URL to hand, but you may want to do a google for the
"Binary Black Hole Grand Challenge Alliance".

davidoff

davidoff404 wrote in message ...

In principle, yes. In practise, absolutely not.

There's obviously something very deep going on in the mathematics of
general relativity that we don't understand yet. The most promising
candidates for simulating events that will produce detectable
gravitational waves (for example, binary black hole coalescence;
inspiralling binary neutron stars; grazing black hole collisions) are
being produced using modified BSSN formulations or Jim York's
first-order symmetric hyperbolic work.

davidoff

http://www.crpc.rice.edu/CRPC/demos/BlackHole/gc1.html

Yes I see what you mean.

If I said the names of the following, Sacherri, Gauss and Rienmann,
what would come to your mind? If we considered the spacetime fabric
as flat, would we also say it is absent of gravitational waves?

Sol