Viewpoint: Causality in the Quantum World

Martin Ringbauer

Časlav Brukner

Xiaoyang Yu

Humans are limited in what they know by the technical limitation of their cortical language network. A reality is a situation model. The universe is a collection of self-driven mathematical entities. If we are happy to accept randomness, it’s obviously possible that all other so-called “worlds” in the many-worlds interpretation don’t exist objectively. From the viewpoint of an imagined external observer (who is located somewhere outside of all worlds), in all worlds, every self-driven elementary particle is changing its state to match its fated state, together form a single fated self-driven state machine; the so-called “subjective reality” (aka the so-called “subjective conscious experience”) is actually the use of a mathematical model (MM) by a Turing machine (TM). The so-called “subjective reality” shouldn’t be able to alter/impact the fated world line of any elementary particle within this world. Except one objective MM which is a fitted MM of the objective reality, every other causality is not an objective MM but a Granger causality, and is an under-fitted MM of the objective reality.

Xiaoyang Yu

Humans are limited in what they know by the technical limitation of their cortical language network. A reality is a situation model. The universe is a collection of self-driven mathematical entities. If we are happy to accept randomness, it’s obviously possible that all other so-called “worlds” in the many-worlds interpretation don’t exist objectively. The so-called “physical interaction” (aka objective interaction) among any number of elementary particles is consistent with the so-called “physical law”. From the viewpoint of an imagined external observer (who is located somewhere outside of all worlds), in all worlds, every self-driven elementary particle is changing its state to match its fated state, together form a single fated self-driven state machine; the so-called “subjective reality” (aka the so-called “subjective conscious experience”) is actually the use of a mathematical model (MM) by a Turing machine (TM). The so-called “subjective reality” shouldn’t be able to alter/impact the fated world line of any elementary particle within this world. Except one objective MM which is a fitted MM of the objective reality, every other causality is not an objective MM but a Granger causality, and is an under-fitted MM of the objective reality.

Benjamin F. Dribus

This paper offers suggested improvements to the causal sets program in discrete gravity, which treats spacetime geometry as an emergent manifestation of causal structure at the fundamental scale. This viewpoint, which I refer to as the causal metric hypothesis, is summarized by Rafael Sorkin's phrase, "order plus number equals geometry." Proposed improvements include recognition of a generally nontransitive causal relation more fundamental than the causal order, an improved local picture of causal structure, development and use of relation space methods, and a new background-independent version of the histories approach to quantum theory. Besides causal set theory, à la Bombelli, Lee, Meyer, and Sorkin, this effort draws on Isham's topos-theoretic framework for physics, Sorkin's quantum measure theory, Finkelstein's causal nets, and Grothendieck's structural principles. This approach circumvents undesirable structural features in causal set theory, such as the permeability of maximal antichains, studied by Major, Rideout, and Surya, and the configuration space pathology arising from the asymptotic enumeration of Kleitman and Rothschild. The paper culminates in the theory of co-relative histories and kinematic schemes, combining the causal metric hypothesis, the histories approach to quantum theory, and Grothendieck's relative viewpoint. This leads to the derivation of causal Schrödinger-type equations as dynamical laws for discrete quantum spacetime.

Christina Giarmatzi