Robert Dicke and the naissance of experimental gravity physics, 1957-1967

TL;DR

The paper reviews the pivotal decade from 1957 to 1967 when experimental gravity research transitioned into a recognized scientific field, highlighting technological advances, key figures like Robert Dicke, and the importance of empirical testing over purely theoretical arguments.

Contribution

It provides a historical analysis of the emergence of experimental gravity physics, emphasizing the role of technological progress, contingency, and nonempirical evidence in establishing gravity theories.

Findings

Experimental gravity became a recognized scientific field in the late 1950s.

Technological advances were crucial for progress in experimental gravity.

Empirical testing can lead to surprising confirmations of theories.

Abstract

The experimental study of gravity became much more active in the late 1950s, a change pronounced enough be termed the birth, or naissance, of experimental gravity physics. I present a review of developments in this subject since 1915, through the broad range of new approaches that commenced in the late 1950s, and up to the transition of experimental gravity physics to what might be termed a normal and accepted part of physical science in the late 1960s. This review shows the importance of advances in technology, here as in all branches of natural science. The role of contingency is illustrated by Robert Dicke's decision in the mid-1950s to change directions in mid-career, to lead a research group dedicated to the experimental study of gravity. The review also shows the power of nonempirical evidence. Some in the 1950s felt that general relativity theory is so logically sound as to be scarcely worth the testing. But Dicke and others argued that a poorly tested theory is only that, and that other nonempirical arguments, based on Mach's Principle and Dirac's Large Numbers hypothesis, suggested it would be worth looking for a better theory of gravity. I conclude by offering lessons from this history, some peculiar to the study of gravity physics during the naissance, some of more general relevance. The central lesson, which is familiar but not always well advertised, is that physical theories can be empirically established, sometimes with surprising results.