Quantum revolution

Soon after the quantum revolution of the mid 1920s, Linus Pauling and John C. Slater expanded Lewis s localized electronic-structural concepts with the introduction of directed covalency in which bond directionality was achieved by the hybridization of atomic orbitals.1 For normal and hypovalent molecules, Pauling and Slater proposed that sp" hybrid orbitals are involved in forming shared-electron-pair bonds. Time has proven this proposal to be remarkably robust, as has been demonstrated by many examples in Chapter 3. 

Thus the transformation of the default picture of the fundamental stmcture of matter underwent a thorough transformation during this time— and we have not even mentioned the quantum revolution during the latter portion of this same time. The foundations of matter must have appeared none too solid to many of the researchers of the period. 

E.B. Bolles, Einstein Defiant. Genius versus Genius in the Quantum Revolution, Joseph Henry Press, Washington, EX , 2004, pp. 286. 

A tentative answer to this question is affirmative. As noted by Dowling and Milburn [33], we are moving from passive observers to active experimenters "In the second quantum revolution, we are actively employing quantum mechanics to alter the quantum face of our physical world."... 

J.P. Dowling, G.J. Milburn, Quantum technology The second quantum revolution, Phil. Trans. R. Soc. London, A 361 (2003) 1655-1674. 

Refs. [i] Born M (1920) Z Phys 1 45 [ii] Born M, Oppenheimer JR (1927) Ann Phys 84 457 [in] Born M (1954) The statistical interpretation of quantum mechanics. Nobel Lecture [iv] http //nobelprize.org/index.html [vi] Thorndike Greenspan N (2005) The end of the certain world. The life and science of Max Born. The Nobel physicist who ignited the quantum revolution. Basic Boohs (German translation Thorndike Greenspan N (2006) Max Born -Baumeister der Quantenwelt. Elsevier, Munchen)... 

To understand the far-reaching nature of the quantum revolution, you should consider the state of physics at the end of the 19th century. The 200 years that followed the seminal work of Isaac Newton were the classical period in the study of mechanics, the branch of physics that predicts the motions of particles and the collections of particles that make up working mechanisms. By the end of that period, about 1900, physicists had achieved a deep understanding that successfully dealt with problems ranging from the motions of the planets in their orbits to the design of a bicycle. These achievements make up the field now called classical mechanics. 

This led to the important discoveries of Albert Einstein and the quantum revolution at the heart of modern chemistry. Modern chemical pioneers Gilbert Newton Lewis, Linus Pauling, and Mulliken elucidated the fundamental concepts of the electron as the heart of chemical bonding [1, 28, 29]. The role of the electron in modern society is much too extensive to chronicle. Radio, television, nuclear weapons and power are but a few applications. Indeed, the ultimate importance of the electron is easily realized if we return to the idea that all matter contains electrons. 

Brow94 Julian Brown A Quantum Revolution For Computing New Scientist 24/1944 (Sept. 1994) 21-24. 

The history of chemistry is a story of human endeavor— and as erratic as human nature itself. Progress has been made in fits and starts, and it has come from all parts of the globe. Because the scope of this history is considerable (some 100,000 years), it is necessary to impose some order, and we have organized the text around three discernible—albeit gross—divisions of time Part 1 (Chaps. 1-7) covers 100,000 BCE (Before Common Era) to the late 1700s and presents the background of the Chemical Revolution Part 2 (Chaps. 8-14) covers the late 1700s to World War I and presents the Chemical Revolution and its consequences Part 3 (Chaps. 15-20) covers World War I to 1950 and presents the Quantum Revolution and its consequences— and hints at revolutions to come. 

The second quantum revolution as lliis continuing further development of quantum physical thinking is called by Alain Aspect, one of the pioneers in this field one expects a deeper imderstanding of quantum physics itself but also applications in engineering. There is already the term quantum engineering which describes scientific activities to apply particle wave duality or entanglement for practical purposes, for example, nano-machines, quantum computers, etc. [8, 9] (Fig. 6.1). 

Most practicing physicists have learned what little they know of the history of this period by reading textbooks written after the quantum revolution. Often texts and teaehers treat the Planck radiation law, the Einstein photoelectric equatiorr, the Bohr atom and the Compton effect in one sequence assuming that this provides an adequate background for understanding E = hv and p = hv/c [de Broglie s equation]. This can leave a student with less than total respect for the physicists who took so long to see the obvious necessity for this form of quantization (p. 95). 

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