Einstein and the Quantum: The Quest of the Valiant Swabian

by A. Douglas Stone, Director, Yale's Division of Physical Sciences
Princeton University Press, Princeton, NJ, 2013
344 pp., illus. 23 b/w. Trade, $29.95
ISBN: 9780691154633.

Reviewed by Christopher B. Germann,
Cognition Institute
Plymouth University

christopher.germann@plymouth.ac.uk 

This book sheds new light quanta on Einstein’s multifaceted life. The take-home message is that Einstein’s thinking was essential to the development of quantum theory even though his contributions are usually underemphasized or even neglected in the scientific discourse.

The book is subdivided into 29 chapters and the text is peppered with numerous footnotes of historical facts and bibliographical details about many of the significant physicist of this era such as Planck, Bohr, Schrödinger, Heisenberg, de Broglie, Dirac, Born, etc. pp. The reference section includes a comprehensive collection of Einstein’s correspondences, his landmark papers, and his lesser-known works.

Stone highlights the role of the “valiant Swabian’s” creative genius as being pivotal to the evolution of modern quantum theory. On the one hand, the scientific community primarily associates Einstein’s contributions with the “relativity revolution” which fundamentally changed our conceptualisation of the cosmology of the universe (e.g., E=mc²). On the other hand, he is perceived as being antagonistic towards the subsequent “quantum revolution”, which revolutionized our thinking about the nature of matter and whose development is mainly (but wrongly according to Stone) attributed to Max Planck. Stone illustrates Einstein’s aversion to the indeterminism inherent in quantum theory by citing his famous “God doesn’t play dice” quote. Moreover, Stone demonstrates that Einstein was clearly discontent with the epistemological implications of quantum theory as exemplified by one of his critical remarks concerning this matter: “Do you really think the moon only exists if I look at it?”

These statements can be regarded as evidence that Einstein vehemently disagreed with the fundamental stochastic indeterminism and non-objectivism advocated by the adherents of the quantum school of thought. Nevertheless, Stone makes very clear that it is Einstein’s (not Planck’s) unorthodox and nonconformist creative thinking which is central to the genesis of quantum theory. In particular, Einstein’s first (sole authored) paper in his “annus mīrābilis” (1905) in which he developed the quantum theory of light heralded the century of quantum theory. His ingenious idea was that light is quantized into indivisible discrete particles, which were at that time labelled quanta and which we now call photons. When he later received the Nobel Prize in 1921 the existence of quanta was still highly controversial. He was credited for the explanation of the photoelectric effect, which is just one of the many implications derived from his deep insights into the quantum world.

In the majority of physics textbooks, Einstein’s key contributions to quantum physics are either underemphasized or completely ignored, but Stone is not the first author who tries to rectify historical facts. For instance, Thomas Kuhn in his book on “Black-Body Theory and the Quantum Discontinuity” describes Einstein’s indispensable contributions to the development of quantum theory. However, Kuhn’s book is mostly inaccessible to non- physicist due to its highly technical nature. Stone clearly and persuasively articulates that it is in Einstein’s creative mind in that the basic concepts which initiated the shift towards the modern quantum theoretical paradigm evolved. Stone enlists four major seminal contributions of Einstein to quantum theory: quantization of energy, wave-particle duality, the probabilistic randomness of quantum mechanics, and what Stone calls “quantum unity” (a.k.a. entanglement).

From a cognitive science perspective, this book is currently highly relevant because it is related to the newly emerging field called “quantum cognition”. This novel paradigm utilizes the mathematical axioms of quantum theory to model cognitive processes (e.g., Pothos & Busemeyer, 2013). Especially the chapter titled “Quantum dice” provides a neat introduction to the counterintuitive logic that underlies Bose-Einstein statistics.

In conclusion, the book at hand is pertinent to anyone interested in physics and the history of science and it is, for the most part, accessible by a lay audience. However, even though mathematical equations are rare, it should be noted that some background knowledge in physics is required in order to understand the discipline specific terminology and to fully appreciate the depth of Stones elaborations. Having said that, even specialised physicists will not be disappointed by the author’s scholarly efforts.

References:

Einstein, A., (1905). Über einen die Erzeugung und Verwandlung des Lichtes betreffenden heuristischen Gesichtspunkt (On a Heuristic Viewpoint Concerning the Production and Transformation of Light), Annalen der Physik, 17(6). 132-148.

Kuhn, T. S. (1978). Black-Body Theory and the Quantum Discontinuity, 1894-1912. Oxford: Clarendon Press.

Pothos, E. M., & Busemeyer, J. R. (2013). Can quantum probability provide a new direction for cognitive modelling. Behavioral and Brain Sciences, 36, 255-274.