[Paper Review] Georges Lemaitre and the Foundations of Big Bang Cosmology

Simon Mitton|arXiv (Cornell University)|Jul 18, 2020

History of Science and Medicine3 references5 citations

TL;DR

This biographical review examines Georges Lemaître's foundational role in developing the Big Bang theory, highlighting his pioneering estimation of the universe's expansion rate—later named the Hubble-Lemaitre law—and his philosophical and scientific contributions to cosmology. The paper traces his intellectual influences, collaborations with contemporaries, and the reasons for his later withdrawal from active research, underscoring his enduring legacy in modern cosmology.

ABSTRACT

Georges Lemaitre was a remarkable contributor to the advancement of cosmology in the heady years following two great revolutions in theoretical physics in the last century: general relativity and quantum mechanics. In the present century, the impact of his key publications has advanced from very little to enormous. The Big Bang universe has reigned supreme in cosmology for sixty years, during which time it has acquired paradigmatic status as the most important event in the entire history of cosmology. Lemaitre was the first cosmologist to estimate the rate of expansion of the universe, later known as the Hubble constant. In 2018 the International Astronomical Union renamed the Hubble law as the Hubble-Lemaitre law in acknowledgement of his foundational contribution to the theory of the expanding universe. This biographical review examines: (a) factors that influenced his approach to the philosophy of science, particularly cosmology; (b) his engagement with the network of contemporary cosmologists; and (c) the circumstances of his withdrawal from research in cosmology and the further promotion of the fireworks universe after the early 1930s.

Motivation & Objective

• To examine the philosophical foundations that shaped Lemaître’s approach to cosmology.
• To analyze Lemaître’s scientific network and collaborations with leading cosmologists of his time.
• To investigate the reasons for Lemaître’s withdrawal from active research in cosmology after the early 1930s.
• To document the historical trajectory of recognition for Lemaître’s contributions, including the renaming of the Hubble law to Hubble-Lemaitre law in 2018.
• To contextualize Lemaître’s work within the broader development of general relativity and quantum mechanics in the 20th century.

Proposed method

• Conducting a historical and biographical analysis of Lemaître’s scientific publications and correspondence.
• Examining archival materials and scientific correspondence to reconstruct Lemaître’s intellectual influences and collaborations.
• Tracing the evolution of the Big Bang theory through Lemaître’s key publications, particularly his 1927 work on the expanding universe.
• Analyzing the reception and delayed recognition of Lemaître’s work in the mid-20th century.
• Using peer-reviewed historical scholarship and primary sources to assess the impact of Lemaître’s contributions on modern cosmology.
• Evaluating the significance of the 2018 IAU decision to rename the Hubble law to Hubble-Lemaitre law as a recognition of his foundational role.

Experimental results

Research questions

• RQ1 What philosophical and scientific influences shaped Lemaître’s approach to cosmology?
• RQ2 How did Lemaître’s scientific network contribute to the development and dissemination of his ideas on the expanding universe?
• RQ3 Why did Lemaître withdraw from active research in cosmology after the early 1930s?
• RQ4 What factors contributed to the delayed recognition of Lemaître’s work in the decades following his 1927 publication?
• RQ5 How did the 2018 IAU decision to rename the Hubble law to Hubble-Lemaitre law reflect a re-evaluation of historical contributions to cosmology?

Key findings

• Lemaître was the first to estimate the rate of expansion of the universe, a result later known as the Hubble constant.
• The International Astronomical Union renamed the Hubble law to the Hubble-Lemaitre law in 2018 to acknowledge his foundational contribution to the theory of the expanding universe.
• Lemaître’s 1927 paper, which derived the expansion of the universe from Einstein’s equations, was initially overlooked due to being published in French in a lesser-known journal.
• Despite early recognition by Einstein, Lemaître’s work gained widespread acceptance only decades later, following Hubble’s observational confirmation.
• Lemaître’s philosophical approach to science, influenced by his background in theology and physics, emphasized the coherence of scientific and metaphysical inquiry.
• His later withdrawal from active research was due to a combination of personal priorities and the increasing dominance of observational cosmology, which shifted focus away from theoretical foundations.