The Guest Editorial by Brian Greene in New Scientist is a pretentious peroration in favour of ‘nothing’ – of beliefs that space is empty – and shows the poverty of reductionist physics.
He’s wrong that Isaac Newton saw space as empty, for the latter believed in the aether (or several aethers) as Paul Davies’s article says. Johannes Kepler had conjectured a force in the Earth that causes the Moon to move, while Newton’s contemporaries contested the algebraic law of gravity on the grounds that action-at-a-distance is non-science. But not until Michael Faraday (~1850s) did the concept of a field of force, filling space, come to the fore.
Greene’s empty space is a false concept – space is filled with physical fields, zeropoint radiation / quantum fluctuations and dark energy. Paul Davies’s article embraces this physics – “the notion that space is a mere void with no physical properties is no longer tenable” – so why did Greene’s editorial ignore it?
As Davies says, fields possess energy and exert pressure. Recasting of Einstein’s unified field equation with a true (not pseudo) tensor shows gravity is not only geometry (Leonid Grishchuk). Gravitational wave scientists are seeking to detect physical waves, comprising propagating energy pulses. The idea of gravity as just geometry – the ‘shape of nothing’, Greene calls it – is plain wrong.