Thursday, February 1, 2024

The World is not Discrete

Some people like to say that Quantum Mechanics makes the world discrete. That is not true. But I always assumed that QM models could be approximated by lattice models.

Apparently this is not true. We know that the weak force is chiral, ie, it violates mirror reflection symmetry. Neutrinos are left-handed in the Standard Model.

From the Scott Aaronson blog:

“There is currently no fully satisfactory way of evading the Nielsen-Ninomiya theorem. This means that there is no way to put the Standard Model on a lattice. On a practical level, this is not a particularly pressing problem. It is the weak sector of the Standard Model which is chiral, and here perturbative methods work perfectly well. In contrast, the strong coupling sector of QCD is a vector-like theory and this is where most effort on the lattice has gone. However, on a philosophical level, the lack of lattice regularisation is rather disturbing. People will bang on endlessly about whether or not we live “the matrix’”, seemingly unaware that there are serious obstacles to writing down a discrete version of the known laws of physics, obstacles which, to date, no one has overcome.”
There is a whole industry of physicists doing lattice approximations to the SM, but the SM is chiral and the approximations are not, so there is no hope that the approximations converge to the SM.

Aaronson is commenting on the silly idea that we live in a computer simulation. If we did, it would raise another silly idea that we could overwork the simulator by doing certain experiments.


  1. There is no 'weak force', just a black box kludge to say 'we have no idea why functionally so we just created a magical teeny tiny bullshit force that does something'. The weak force is not science, it is a heuristical (black box) solution pretending to be science. This kind of nonsense is why Dark Matter is so casually employed on the macro side of the scale to explain away utter gravity model failure instead of finding out a real solution.

    Fix your damn atomic models. Jettison Rutherford monkey bread nuclei and 'electrons do everything' drivel, explain how the nucleus functions mechanically and how they take in energy to continue moving as they do. Presently, atomic models runs entirely on fairy farts, since they have no explicable way to take in, utilize, and expel energy, which is actually required if you want them to act like atoms and emit heat. Do this and then you won't have to worry about imaginary black box forces to stop your atoms from blowing up or collapsing in on themselves.

  2. I have never understood the whole 'the universe is a simulation' argument, since to embrace it is to jettison all precepts of science. You might as well argue that 'life is but a dream' and see where that goes... which is nowhere with nothing to show for it.