[tlb]

We have, today, approximate models that are simple. But they're not quite exact for things like quantum gravity. If you want an exact model, it is presumably longer. Presumably, because smart people have looked for a long time for simple models that are more accurate and haven't found one.

If the exact model is only moderately long, then we (or a Turing machine) can discover and simulate it. But it's at least conceivable that the shortest-possible exact description of physics is extremely long.

[garmaine]

The issue is more of data availability. Quantum gravity is hard to pin down because the differences are not observable at energies we can test or at cosmic scales we can measure. If we had a probe skirting the event horizon of a black hope the answer might be obvious. But we don’t.