Probability and Causality in Quantum Physics

Henry Margenau

Xiaohui Jiang

M.Born's notions on causality are that Quantum World is governed by causality and chance jointly;that quantum particle has the intrinsic property of uncertainty,and the law of chance is the last law of nature;and that the concepts of probability and chance are more elementary than causality.While D.Bohm's notions of potential causality are that there is no last law of nuture at all,and each level manifests unique rules;that causality is just relative necessity and contingency always appears on the cross point of many different factors or probable tendencies;that the potential causality interpretation is some kind of integration of causal determination and probability statistics,which has clear intuitive model in physics,and has definite ontological base in philosophy.

Patrick Suppes

Marco Zaopo

Quantum theory is a mathematical formalism to compute probabilities for outcomes happenning in physical experiments. These outcomes constitute events happening in space-time. One of these events represents the fact that a system located in the region of space where is situated a physical device has a certain value of a physical observable at the time when the device fires the outcome corresponding to that value of the observable. The causal structure of these events is customarily assumed fixed in an absolute way. In this paper we show that this assumption cannot be substantiated on operational grounds proving that two observers looking at the same quantum experiment can calculate the probabilities of the experiment assuming a different causal structure for the space-time events constituted by the outcomes. We will thus say that in quantum theory we have relativity of causal structure.

Giulio Chiribella

This presentation provides a non-technical overview of the notion of quantum superposition of causal structures, of its applications, and of its proposed physical realizations. The conceptual underpinning for these investigations is a view of quantum theory as a new kind of probability theory. At the axiomatic level, the principles of this new kind of probability theory suggest new causal relations that have no analogue in the classical world. These new causal relations are a potential resource for new technologies, including computation and communication technology.

Patrick Suppes