The main stumbling stone of the local hype is inability of our current gravitational telescopes to study sources operating at all possible frequencies. Gravitational wave sources might have a variety of frequencies, and LIGO is sufficiently sensitive in a swath of spectrum only. At low frequencies, scattered light, seismic and control noise dominate; in the mid-band, thermal noise in the mirror dielectric coatings of LIGO rules. At high frequencies, quantum noise is the ultimate limiter.

Our instruments are hence better suited to looking on far quasars or binary black hole systems than inside the heart of our home thermonuclear hearth. Gravitational radiation is also quite weak, although impossible to screen from (in some modern theories, more or less exotic, this everpresence of gravity is said to be the result of its “leaking” between branes into a “bulk” spacetime proper, while all other forces of nature are localized within a brane inside a spacetime of higher dimensionality). A very strong gravitational wave would produce displacements on the order of 0.1 femtometer — this is about the diameter of a proton. More typical strains from astrophysical sources are on the order of 1 zeptometer, i.e., 100,000 times less.

Gravitational wave primordial background is still dark before our eyes.