I've done some more work - apparently nonperiodic tiling is uncomputable. This is used to make toilet roll more compressed (that's why the sheets don't line up)

I've done some more work - apparently nonperiodic tiling is uncomputable. This is used to make toilet roll more compressed (that's why the sheets don't line up) and that must count as a manifestation of the uncomputable in our physical universe. I think this is a reasonable proof that the physical universe is uncomputable.