# Foundations of quantum physics IV. More on the thermal interpretation

## TL;DR

This paper elaborates on the thermal interpretation of quantum physics, explaining how classical features emerge, discussing measurement processes, and analyzing standard experiments within this interpretative framework.

## Contribution

It provides new technical developments and intuitive explanations supporting the thermal interpretation, including how spectral features and measurement outcomes are understood.

## Key findings

- Spectral features and classical dynamics emerge under certain conditions.
- Measurement of a qubit via q-expectation can produce binary detection events.
- Analysis of standard experiments from the thermal interpretation perspective.

## Abstract

This paper continues the discussion of the thermal interpretation of quantum physics. While Part II and Part III of this series of papers explained and justified the reasons for the departure from tradition, the present Part IV summarizes the main features and adds intuitive explanations and new technical developments. It is shown how the spectral features of quantum systems and an approximate classical dynamics arise under appropriate conditions. Evidence is given for how, in the thermal interpretation, the measurement of a qubit by a pointer q-expectation may result in a binary detection event with probabilities given by the diagonal entries of the reduced density matrix of the prepared qubit. Differences in the conventions about measurement errors in the thermal interpretation and in traditional interpretations are discussed in detail. Several standard experiments, the double slit, Stern--Gerlach, and particle decay are described from the perspective of the thermal interpretation.