Preludes to dark energy: Zero-point energy and vacuum speculations

TL;DR

This paper explores the historical development of zero-point energy concepts and their early connections to dark energy and the cosmological constant, highlighting uncoordinated scientific steps over the past century.

Contribution

It provides a historical analysis of the origins and evolution of zero-point energy ideas and their relation to dark energy and the cosmological constant.

Findings

Zero-point energy ideas date back to early 20th century.

Connections between vacuum energy and the cosmological constant were recognized in the 1960s.

Early hypotheses on vacuum energy influenced modern dark energy theories.

Abstract

Although dark energy is a modern concept, some elements in it can be traced back to the early part of the twentieth century. This paper examines the origin of the idea of zero-point energy and in particular how it appeared in a cosmological context in a hypothesis proposed by Walther Nernst in 1916. The hypothesis of a zero-point vacuum energy attracted some attention in the 1920s, but without attempts to relate it to the cosmological constant that was discussed by Georges Lema\^itre in particular. Only in the late 1960s was it recognized that there is a connection between the cosmological constant and the quantum vacuum. As seen in retrospect, many of the steps that eventually led to the insight of a kind of dark energy occurred isolated and uncoordinated.