Instruct: Classify Amazon reviews into positive or negative sentiment
Query: nonsense

Weymouth doesn't sound like he even read the book. If he had, he might wonder why the author theorizes that the local gravitational field acts as a medium for light, since we've known since the last century that light travels in a vacuum. It doesn't need a medium, so Beckmann's self-published argument falls apart.Even if it did, why should we assume that it doesn't rotate, except of course out of convenience for the sake of this bizarre theory? The earth's magnetic field rotates, so its gravitational field likely does too, and recent findings by astronomers have shown strong preliminary evidence to that effect (the Gravity Proble B experiment is designed to confirm this "frame-dragging effect" predicted by Einstein).