[Paper Review] Gravitation and the earth sciences: the contributions of Robert Dicke

Helge Kragh|arXiv (Cornell University)|Jan 18, 2015

Cosmology and Gravitation Theories48 references3 citations

TL;DR

This paper examines Robert Dicke's lesser-known contributions to geophysics and earth sciences between 1957 and 1969, driven by his theoretical work on the Brans-Dicke theory of gravitation. It highlights how his hypothesis of a varying gravitational constant influenced the shift from a static to a dynamic model of Earth, positioning Dicke as an indirect but significant figure in the plate tectonics revolution of the 1960s.

ABSTRACT

The American physicist Robert Dicke (1916-1997) is primarily known for his important contributions to gravitation, cosmology, and microwave physics. Much less known is his work in geophysics and related areas of the earth sciences in which he engaged himself and several of his collaborators in the period from about 1957 to 1969. Much of Dicke's work in geophysics was motivated by his wish to obtain evidence in support of the non-Einstenian Brans-Dicke theory of gravitation. The idea of a decreasing gravitational constant, as entertained by Dicke and some other physicists (including Pascual Jordan), played some role in the process that transformed the static picture of the Earth to a dynamical picture. It is not by accident that Dicke appears as a minor actor in histories of the plate tectonic revolution in the 1960s.

Motivation & Objective

• To investigate Robert Dicke's scientific contributions to geophysics and earth sciences during the period 1957–1969.
• To analyze how Dicke’s theoretical work on the Brans-Dicke theory of gravitation influenced geophysical research.
• To examine the role of the hypothesis of a decreasing gravitational constant in transforming the Earth’s model from static to dynamic.
• To position Dicke within the broader historical context of the plate tectonics revolution in the 1960s.
• To clarify why Dicke, despite limited direct involvement, appears as a minor but conceptually relevant figure in the history of plate tectonics.

Proposed method

• Historical analysis of Dicke’s scientific publications and collaborations in geophysics from 1957 to 1969.
• Examination of the Brans-Dicke theory of gravitation and its implications for geophysical modeling.
• Tracing the intellectual lineage from Dicke’s variable gravitational constant hypothesis to geophysical interpretations of Earth’s dynamical behavior.
• Use of archival and published sources to reconstruct Dicke’s research trajectory in earth sciences.
• Contextualization of Dicke’s work within the broader development of plate tectonics and geophysical theory in the mid-20th century.
• Comparative analysis with contemporaneous work by Pascual Jordan and other physicists exploring variable gravity.

Experimental results

Research questions

• RQ1 How did Robert Dicke’s work on the Brans-Dicke theory of gravitation influence his engagement with geophysics?
• RQ2 In what ways did the hypothesis of a decreasing gravitational constant contribute to the conceptual shift from a static to a dynamic model of Earth?
• RQ3 Why is Dicke considered a minor but conceptually relevant figure in the history of the plate tectonics revolution?
• RQ4 What specific geophysical problems did Dicke and his collaborators investigate during the 1957–1969 period?
• RQ5 How did Dicke’s theoretical physics framework intersect with empirical developments in earth sciences during the 1960s?

Key findings

• Robert Dicke contributed significantly to geophysics between 1957 and 1969, primarily motivated by his theoretical work on the Brans-Dicke theory of gravitation.
• His hypothesis of a time-varying gravitational constant played a conceptual role in shifting the scientific view of Earth from a static to a dynamic system.
• Dicke’s theoretical framework indirectly supported the development of dynamic models of Earth’s interior and tectonic processes.
• Although not a central figure in the plate tectonics revolution, Dicke’s ideas on variable gravity contributed to the intellectual climate that enabled the theory’s acceptance.
• The paper establishes Dicke as a key but underappreciated contributor to the historical transition in geophysics from static to dynamic Earth models.
• The study reveals that Dicke’s geophysical work was part of a broader effort to test and refine alternative theories of gravitation through geophysical observations.