Is nature continuous or discrete? How the atomist error was born
Thomas Nail
Thomas Nail
Quote:Quantum gravity is of enormous importance. According to its proponents, it stands poised to show the world that the ultimate fabric of nature (space-time) is not continuous at all, but granular, and fundamentally discrete. The atomist legacy might finally be secured, despite its origins in an interpretive error.
There is just one nagging problem: quantum field theory claims that all discrete quanta of energy (particles) are merely the excitations or fluctuations in completely continuous quantum fields. Fields are not fundamentally granular. For quantum field theory, everything might be made of granules, but all granules are made of folded-up continuous fields that we simply measure as granular. This is what physicists call ‘perturbation theory’: the discrete measure of that which is infinitely continuous and so ‘perturbs one’s complete discrete measurement’, as Frank Close puts it in The Infinity Puzzle (2011). Physicists also have a name for the sub-granular movement of this continuous field: ‘vacuum fluctuations’. Quantum fields are nothing but matter in constant motion (energy and momentum). They are therefore never ‘nothing’, but more like a completely positive void (the flux of the vacuum itself) or an undulating ocean (appropriately called ‘the Dirac sea’) in which all discrete things are its folded-up bubbles washed ashore, as Carlo Rovelli puts it in Reality Is Not What it Seems (2016). Discrete particles, in other words, are folds in continuous fields.
The answer to the central question at the heart of modern science, ‘Is nature continuous or discrete?’ is as radical as it is simple. Space-time is not continuous because it is made of quantum granules, but quantum granules are not discrete because they are folds of infinitely continuous vibrating fields. Nature is thus not simply continuous, but an enfolded continuum.
This brings us right back to Lucretius and our original error. Working at once within and against the atomist tradition, Lucretius put forward the first materialist philosophy of an infinitely continuous nature in constant flux and motion. Things, for Lucretius, are nothing but folds (duplex), pleats (plex), bubbles or pores (foramina) in a single continuous fabric (textum) woven by its own undulations. Nature is infinitely turbulent or perturbing, but it also washes ashore, like the birth of Venus, in meta-stable forms – as Lucretius writes in the opening lines of De Rerum Natura: ‘Without you [Venus] nothing emerges into the sunlit shores of light.’ It has taken 2,000 years, but perhaps Lucretius has finally become our contemporary.
'Historically, we may regard materialism as a system of dogma set up to combat orthodox dogma...Accordingly we find that, as ancient orthodoxies disintegrate, materialism more and more gives way to scepticism.'
- Bertrand Russell
- Bertrand Russell