📓 wolfram physics.md by @flancian ☆

a [[project]].
- led by [[stephen wolfram]]
- recommended by:
  - [[stephen wolfram]] ;)
  - maybe [[lex fridman]] with their impressive multi hour podcast together.
  - [[xiq]]
- #technical https://www.wolframphysics.org/technical-introduction/potential-relation-to-physics/cosmology-expansion-and-singularities/
- #paper https://arxiv.org/abs/2004.08210
- #go https://writings.stephenwolfram.com/2020/04/finally-we-may-have-a-path-to-the-fundamental-theory-of-physics-and-its-beautiful/
  - [[hypergraphs]]
  - [[physical space]]
    - [[causal invariance]] https://www.wolframphysics.org/technical-introduction/the-updating-process-for-string-substitution-systems/the-phenomenon-of-causal-invariance/
    - [[multiway graphs]]
      - [[causal graphs]]
        
        [[black holes]] are disconnections in the causal graph
  - [[relativity]]
  - [[quantum physics]] "The Inevitability of Quantum Mechanics" https://hyp.is/DyQ-ADUGEe2WSqvaokeu7w/writings.stephenwolfram.com/2020/04/finally-we-may-have-a-path-to-the-fundamental-theory-of-physics-and-its-beautiful/
    - [[oligons]]
  - [[branchial space]] https://www.wolframphysics.org/technical-introduction/the-updating-process-for-string-substitution-systems/the-concept-of-branchial-graphs/
    - According to Wolfram the [[uncertainty principle]] is due to curvature in [[branchial space]]
    - In the same space, the [[Einstein equations]] are the [[path integral]] (?)
    - #q But causal invariance has other consequences too. One of them is that there should be an analog of special relativity that applies not in spacetime but in branchtime. The reference frames of special relativity are now our quantum observation frames. And the analog of speed in physical space is the rate of entangling new quantum states.
      - which is related to the [[quantum zeno effect]].
    - #q The speed of light c is a fundamental physical constant that relates distance in physical space to time. In our models, there’s now a new fundamental physical constant: the maximum entanglement speed, that relates distance in branchial space to time. I call this maximum entanglement speed ζ (zeta) (ζ looks a bit like a “tangled c”). I’m not sure what its value is, but a possible estimate is that it corresponds to entangling about 10102 new quantum states per second. And in a sense the fact that this is so big is why we’re normally able to “form classical thoughts”.
  - What if there are multiple rules in our universe?
    - #q Or could it be that in some fundamental sense it doesn’t matter what the rules for the universe are: that to observers embedded in a universe, operating according to the same rules as that universe, the conclusions about how the universe works will always be the same?
    - #q In what we’ve discussed so far we’re imagining that there’s a particular, single rule for our universe, that gets applied over and over again, effectively in all possible ways. But what if there wasn’t just one rule that could be used? What if all conceivable rules could be used? What if every updating event could just use any possible rule? (Notice that in a finite universe, there are only ever finitely many rules that can ever apply.)
    - [[greg egan]]‘s [[dust universe]] link, maybe?
    - leads to [[rule space]]
  - [[rule space]]
    - #q It’s a strange but rather appealing picture. The universe is effectively using all possible rules. But as entities embedded in the universe, we’re picking a particular foliation (or sequence of reference frames) to make sense of what’s happening. And that choice of foliation corresponds to a description language which gives us our particular way of describing the universe.
    - #q There’s one immediate thing: that the universe, whatever foliation one uses to describe it, is just a universal computer, and nothing more. And that hypercomputation is never possible in the universe.
  - According to Wolfram, [[computer experiments]] are more flexible than traditional mathematical methodology.