Gravitational Wave Observatory Based on Solid Elastic Spheres

Spherical GW detectors offer a wealth of so far unexplored possibilities to detect gravitational radiation. We find that a sphere can be used as a powerful testbed for any metric theory of gravity, not only GR as considered so far, by making use of a deconvolution procedure for all the 'electric' components of the Riemann tensor. We also find that the sphere's cross section is large at two frquencies, and advantageous at higher frequencies in the sense that a single antenna constitutes a real xylophone in its own.Proposed GW networks will greatly benefit from this. The main features of a two large sphere observatory are reported.