Time in Quantum Theory

Keith Maxwell Hardy

Defining space and time in a manner that agrees more with an observer who measures distance and time with particles, I create a quantum theory of space and time which is more accurate than the special theory of relativity. This new theory, called distance-time theory, predicts the following quantum principles: Heisenberg's uncertainty principle, the probabilistic location of a particle, and the collapse of this probability once a particle is observed. These principles are derived mostly independent of traditional quantum theory, and they are intrinsic properties of time and space in distance-time theory. However, special relativity theory always gives a particle's exact location and speed. This relativistic result disagrees with the quantum principles previously discussed, but it agrees with classical physics. Special relativity theory is a classical theory, while distance-time theory is a quantum theory. Nevertheless, distance-time theory still predicts proven special relativistic results, and there are novel testable predictions made by distance-time theory. The most notable predictions are those regarding the speed of quantum tunneling and certain characteristics of light. Also, distance-time theory defines distance as equivalent to a time period according to the equation D = cT.

Valia Allori

Lev Vaidman A

Recently, several authors have criticized the time-symmetrized quantum theory originated by the work of Aharonov et al. (1964). The core of this criticism was a proof, appearing in various forms, which showed that the counterfactual interpretation of time-symmetrized quantum theory cannot be reconciled with standard quantum theory. I argue here that the apparent contradiction is due to a logical error. I analyze the concept of counterfactuals in quantum theory and introduce time-symmetrized counterfactuals. These counterfactuals do not lead to any contradiction with the predictions of quantum theory. I discuss applications of time-symmetrized counterfactuals to several surprising examples and show the usefulness of the time-symmetrized quantum formalism.

Juan Gonzalo Muga, R. Sala Mayato, I. L. Egusquiza

Lev Vaidman A

Recently, several authors have criticized time-symmetrized quantum theory originated by the work of Aharonov et al. (1964). The core of this criticism was the proof, which appeared in various forms, showing that counterfactual interpretation of time-symmetrized quantum theory cannot be reconciled with the standard quantum theory. I argue here that the apparent contradiction appears due to inappropriate usage of traditional time asymmetric approach to counterfactuals, and that the contradiction disappears when the problem is analyzed in terms of time-symmetric counterfactuals. I analyze various aspects of time-symmetry of quantum theory and defend the time-symmetrized formalism.

Juan Gonzalo Muga, R. Sala Mayato, I. L. Egusquiza