Re: Follow up to question 1147817854.Ph

Hi, Milton

you are right. A gravity wave distorts space-time. Usually one assumes that the distortion is small and the metric is almost the Minkowski metric. Let us denote the distortion by h. Squares of h are neglected. Gravity waves are solutions to the Einstein equation inserting the distorted Minkowski metric into Einstein's equations. To some respect, gravity waves are very similar to electromagnetic waves. A general gravity wave is a superposition of waves with two possible polarizations. Let us assume that the wave propagates along the z-direction and that there is a ring of test-particles in the x-y plane perpendicular to the propagation. If a polarized gravity wave passes the ring of test particles, it will be squeezed in one direction and stretched in the perpendicular direction. This specific form of gravity waves is due to the Einstein equations. The pattern of a general wave will be more complicated as it is a superposition of polarized waves. But still, it will squeeze and stretch distances between particles in the transverse direction of its propagation.
A good reference is the book by Foster and Nightingale, "A short course in General Relativity" or this article on LIGO.

I hope this helps you
regards, Michael