Reality is discrete tho. Check out Planck length. The simulation hypothesis is r...

omnicognate · 2024-07-15T12:05:47 1721045147

The Planck length has no physical significance. It's just a unit of length, chosen for convenience as part of the system of Planck units.

The Planck scale is the scale of lengths/times/etc that are around 1 in Planck units. This happens to be the scale roughly around which the quantum effects of gravity become significant. Since we do not have an accepted quantum theory of gravity, it's therefore the scale at which we cease to have an accepted physical theory.

There is no evidence to suggest that space is discrete at that scale. It's just the scale at which we have no accepted theory, and AFAIK no evidence to evaluate such a theory.

Lichtso · 2024-07-15T14:53:13 1721055193

> The Planck length has no physical significance > There is no evidence to suggest that space is discrete at that scale

Bekenstein bound and "planckian discreteness".

Reality is most likely not composed of a regular tesselation of simple geometric shapes such as a cartesian voxel grid as that would introduce massive anisotropy. But, there is still theoretic evidence suggesting that spacetime is indeed discrete at the lowest level.

omnicognate · 2024-07-15T15:35:18 1721057718

Interesting stuff, and thanks - I didn't know about the Bekenstein Bound. I was referring to empirical evidence, though. AFAICS these are theoretical musings that, while they have some validity as far as they apply to the predictions of existing established theories, have to be considered entirely speculative in the quantum gravity regime where we don't have an accepted theory to base such reasoning on.

Lichtso · 2024-07-15T16:01:41 1721059301

> empirical evidence

That is going to be a though one, at least direct measurements are pretty much ruled out if you consider that the plank length is about a quadrillion (yes, really 10^15) times smaller than the classical electron radius.

So, we will have to settle for indirect evidence and theoretical results.

messe · 2024-07-15T11:24:31 1721042671

Reality, as best we understand it, is very much not discrete, and space is not split into chunks at the Planck length.

A discrete space-time would likely mean observable Lorentz-violations.

Lichtso · 2024-07-15T14:59:49 1721055589

Discrete spacetime does not necessitate a regular and nicely ordered tesselation, it could be pure chaos or be non-geometric.

Before we thought that energy, mass and matter were completely continuous and that turned out to be wrong.

rybosworld · 2024-07-15T14:47:23 1721054843

It's a misconception that the Planck length represents the smallest possible length.

karmakurtisaani · 2024-07-15T14:56:04 1721055364

Indeed, thanks for the correction! However, it would probably be enough for any simulation to be good enough.

smitty1e · 2024-07-16T10:42:35 1721126555

My point is that "probably" falls short of rigorous mathematical proof.

karmakurtisaani · 2024-07-17T06:00:24 1721196024

Surely you're not expecting anything rigorous related to the simulation hypothesis..

smitty1e · 2024-07-17T23:43:30 1721259810

I find it intellectually unsatisfying, so no.

But the way semi-serious people kick the idea around, sure. Pony up. I don't think that my religious beliefs submit to rigor, either. But I'm not here pushing something labeled as "religious beliefs" as a "hypothesis", either.

By the same token, if someone wants to call it the "Simulation Belief" in a religious sense, then I will lay by my dish.