I am told that physicists, astronomers, and cosmologists dream about is the placement of a radio telescope on the far side of the moon. Putting it on the dark side would of course ensure that the planet earth would not be in its way. What is more important, the moon has no atmosphere, so the clarity of radio 'view' the human race would get of distant parts of the cosmos would be ... well, to use a technical phrase, an ass-kicking thrill. And though a radio telescope would be all that, ambitious scientists have additional related ideas. For example, there is a proposal to put a gravitational wave interferometer in the moon. Obvious question ... a whaaaaat? Interferometry is a set of techniques by which waves are made to interfere with one another, creating patterns that convey information. Usually this sort of measurement involves electromagnetic waves. But the study of gravitational waves is a new thing. The first direct observation of gravity waves was recorded in...