Mr. Merrill is frequent contributor to THE SUBMARINE REVIEW and is a published author of several books on the history of undersea technology. He is a retired engineer with lengthy experience at the New London lab of the Naval Undersea WD1fare Center. He currently lives ill Waterford, CT.
“I think it is safe to say that no one understands quantum mechanics.”
-Physicist Richard P. Feynman
Preface
“I think it is safe to say that on one understands quantum mechanics.” -Physicist Richard P. Feynman Quantum mechanics, the study of matter and radiation at an atomic level, provided the foundation of enormous progress in high technology and its many widely used and successful applications in science and industry during the last half of the 20th Century. Two of many current and future areas of application include quantum computing and nuclear fusion. The technology stemming from quantum mechanics has penetrated essentially every aspect of science and the products created surround our daily lives. In 1900, QM was only a concept not clearly understood. A brief narrative of how quantum mechanics began and by 1950 significantly contributed to the growth of the United States’ Gross National Product (GNP) seems fitting.
Quantum considerations apply at the atomic size or where the speed is near that of light. In the summer of 2000, James Bjorkcn, Stanford University emeritus physics professor, commented “Quantum Theory works. It never fails. And the scope of the applications is enormous.
At the end of the 19•h Century, unobservable concepts at the atomic level were not within in the awareness of most scientists. Quantum mechanics deals with the interactions of matter and radiation in terms of observable quantities. Further, quantum mechanics has been very successful in giving correct results in practically every situation to which it has been applied.
The aim of this paper is to share the author’s limited grasp of quantum concepts and to bring some of the ways that they are in our purview at the beginning of the new century and an important growing presence in the future. By the end of the 20th Century, quantum brought order to the understanding of the atomic domain from crystals the size of I centimeter, to the electron less than 10 .,, and quark particles less than 10·33 centimeter. Quantum theory provides the basis for high technology and its huge impact on United States GNP.
It should be noted that pursuing small particles stimulated the need for large-scale equipment, and this pursuit was the beginning of big science. Today, the recent completion of the massive CERN $8 billion particle collider, a 17-mile installation 300 feet beneath the Swiss-French border, epitomizes the need for complex scientific instruments to study the basic constituents of matter, the fundamental particles.
A significant spin-off of CERN is the powerful World Wide Web created there in 1990 to meet the communication needs of thousands of physicists to work with their vast number of colleagues all over the world. By 1993, the WEB quickly spread to the rest of the world and created over $1 trillion worth of commerce on the Internet each year.
Perception
Quanta considerations, even among the cognoscenti, arc still perceived as a challenge. A quote from James Bjorken, one of the world’s most foremost theoretical physicists, provides perspective about the complexity of quantum concepts: “It is often said that no one really understands quantum theory and I would be the last to disagree.”3 A remark from a scientist provides further comment regarding the complexity of quantum theory: “Even today, I believe that in order to truly understand quantum mechanics one has to teach it for at least a couple of years.” Niels Bohr, major contributor to the development of quantum physics for fifty years, remarked, “Anyone who is not shocked by quantum theory has not understood a single word.”
For the general public, perception of quantum often brings to many words like enigmatic, mysterious, unknown, inscrutable, and unfathomable. 1OO Years of quantum Mysteries, the title of a Scientific American article in January 2001 supports these views of quanta theory.
Status
Quantum physics is needed to explain properties of solids, atoms, nuclei and light and is the basis for our understanding of natural phenomena. The quantum scientific revolution kindled in 1900 needed almost thirty years to come to fruition after scientist Max Plank’s creation of the quantum concept. Planck, searching for an explanation of the continuous color spectrum of the frequencies of light emitted from hot bodies derived a formula for results of his experiments. Justification for his derivation led to the concept that the energy of light comes in terms of a basic indivisible unit, a quantum • of light. Coincidentally, 1900 was the year before the first Nobel Prize for physics was awarded.
“Without quantum mechanics we would not have developed the transistor, the semiconductor industry, and the computer industry … the laser, optical communication, and the age of Information technology. There would be no global economy to speak of. It is said, notably, that more than half of the US economy is based on quantum mechanics.”
Current Science, Vol. BC, No. 1, 10 Jan. 2003
A considerable number of the scientific Nobel Prize Laureates were awarded during the 20th Century for contributions to quantum mechanics and by the end of the century; the United States GNP depended on quantum for at least 30% of its total. The products and applications made possible by this complex branch of physics are world wide and particularly in the United States.
In the first decades of the last century, it was a cadre of brilliant, elite and persevering scientists who met and conquered the challenges of ascertaining the complex details of atoms and their structure and provided the basis for the theoretical and mathematical tools for today’s quantum applications dealing with the minutia of electrons, and other particles that surrounding us.
A listing of the scientists contributing is not short but always includes Bohr, Planck, Einstein, De Broglie, Schrodinger, Born, Heisenberg, Pauli and Dirac. Further consideration should be given to the fact that this group, primarily in Europe, of early contributors did not have our instant communication to share their views; and their coming together lacked the ease of modem travel. The early development of quantum mechanics took place during the period from the beginning of the 20’h Century until the late 1900s. Those involved faced the long upheaval of World War I and its aftermath, particularly in Germany, plus a strong and growing antisemitism in the later pre-World War II years.
During the early years of the slowly evolving quanta considerations, those pursuing this path had a limiled array of tools to deal with the experimental side of their investigation. Further, classical physics with centuries of established laws and physics of Newton, Faraday, and Maxwell was not in a one-to-one correspondence with the physics of quanta. Wholehearted acceptance of quantum theory was not universal in the scientific community. Moving from the classical to quantum physics took decades, with final validation and final acceptance in the mid-1920s. It has been noted that even at that time the Nobel Physics Laureate Award Committee was wary of making an award in the era of quanta-related achievement.
A Glimpse of the first Quantum Century
Before Quantum
Physics journals during the last decade of the 19th Century included extensive papers on atomic spectra and essentially every other measurable property of matter resulting from ingenious experimental knowledge. However, the resulting properties of matter were empirical and in some instances lacked proper regard for considerations of systems, science and theory. It was in this environment that the proponents of quantum, heavily theorists, brought their revolutionary approach to physics. Further, “in 1910, about one in five physics papers published in the world was mainly theoretical.”~ As quantum grew and stabilized, an exceedingly large number of experiment proofs would be essential to win its ultimate acceptance.
Quantum Theory Evolving 1900-1930
During these years, acceptance increased and active participation by a great number of the foremost physicists brought their skills to bear while mathematical tools and experimental skills grew swiftly. Quantum never stopped evolving.
In 1905, Albert Einstein wrote four seminal papers that provided the foundation for modern science. Included was a paper on the photoelectric effect for which he received the Nobel Prize in 192 I. It is interesting that at the time the electron had already been discovered, the nucleus of the atom had not. To explain the photoelectric effect, Einstein expanded Planck’s view that the quantification of energy was part of the process of emitting or absorbing light and applied it to the fundamental nature of light itself, a beam of particles whose energies arc related to their frequencies according to Planck’s formula.1 Einstein imbued light with a particle-like behavior. Earlier Maxwell’s theory and extensive experiments testified to light’s wave nature providing a duality. For 20 years, quantum ideas were confused.6 The duality question had to be resolved.
Quantum Challenge
“About 1910 a highly unsatisfactory situation had developed which could be summarized by saying that light is emitted and received as though it consisted of a stream of particles and it is transmitted as though it were a set of waves … it was impossible to be undulatory and corpuscular.”‘ More than a quarter of century of broad scientific effort would be needed to have acceptance, if limited, of this concept.
Ernest Solvay
Early Physics Solvay Conferences
1911 radiation and the quanta
1913 structure of matter
1921 atoms and electrons
1927 electrons and photons
Solvay a wealthy Belgian founded several scientific, philanthropic, and charitable Foundations, including the institutes of physiology (1895) and of Sociology (1901), as well as the prestigious School of Business ( 1903) in Brussels that still bears his name. He saw science as a promise of progress for mankind: ” … I have always sought to serve science because I love science and I see it as a promise of progress for mankind.
In October-November 1911, Solvay organized a meeting in Brussels of most of the famous physicists and chemists of the time. The main objective of this conference was to look at problems of having two different approaches in physics classical physics and quantum physics. Participants included Marie Curie, Albert Einstein, Max Planck, Ernest Rutherford, Raymond Poincare and the Duke Louis de Broglie. This was the first meeting of the Physics Council of the Solvay Conferences. Solvay Conferences have continued into the 2111 Century. Early Solvay Conferences provided a crucible for discussion and exchange that brought about a consensus on quantum theory in the October 1927 Conference.
Between Planck’s quantization concept in 1900 and the 1927 Brussels meeting, significant progress favorable to the acceptance of quantum physics occurred. Those attending included Niels Bohr, Albert Einstein, Wolfgang Pauli, Louis de Broglie, Edwin Schrodinger, and Werner Heisenberg. It was the results of the experimental work, theoretical papers, mathematical developments and strong advocacy for quantum concepts at the 1927 Solvay Conference that led to Quantum Mechanics 1925-1927 Triumph of the Copenhagen Interpretation. This announcement honored Bohr of Copenhagen for his important contribution to the new and revolutionary physics.
A seminal paper presented by Werner Heisenberg and Max Born announced, “We regard quantum mechanics as a complete theory for which the fundamental physics and mathematical hypotheses arc no long susceptible of modification. ”
A comment by esteemed physicist and science writer Heinz R. Pagels in The Cosmic Code ( 1983) views the result of the Brussels meeting as follows. “The Copenhagen interpretation magnificently revealed the internal consistency of the quantum theory, a consistency which was purchased at the price of renouncing the determination and objectivity of the natural world.”
Quantum Consensus and Philosophy 1927′
Copenhagen Interpretation of Quantum Mechanics
Mathematical equations of quantum theory arc supported experimentally.
Quantum world cannot be visualized like the Newtonian world.
Randomness and probabilities arc part of the quantum scene.
What goes on in the quantum world depends on how it is observed.
An electron clearly a particle could sometimes behave as a wave.
Quantum theory makes only statistical predictions.
Atoms and molecules absorb and emit light.
Uncertainty, it is impossible to achieve absolute knowledge of all aspects of a systems condition.
After Consensus
It should be mentioned that as early as 1910, there were an increasing number of physicists, primarily at the universities across Europe and in the United States pursuing doctoral studies on radioactivity, X-rays, and especially electrons.10 The events at Copenhagen in 1927 provided the mathematics to describe accurately the outcomes of the quantum experiments. With this assist, a good number of physicists worked out new applications to address unsolved problems of nuclear physics.11 Quantum theory began to be successfully applied to atoms, molecules, and solids.
The Reality
Applications
Quantum applications surround us. “All high-tech products have been created on the basis of our detailed knowledge of atomic structures and we have gained this knowledge on the basis of theoretical foundations of quantum mechanics, the one branch of modem physics that deals with strange behavior of microcosms of atoms.”
Today, the breadth of quantum mechanics areas of application includes condensed matter physics, solid-state physics, atomic physics, molecular physics, computation chemistry, quantum chemistry, particle physics, and nuclear physics. Quantum mechanics describes the actions of subatomic particles, electrons, protons, neutrons and photons.
Modern technology operates at a scale where quantum effects arc significant. Examples include the laser, the transistor, the electron microscope, superconductivity and magnetic resonance imaging. The transistor is indispensable for modern electronics.
Researchers are currently seeking robust methods of directly manipulating quantum states. Efforts are being made to develop quantum cryptography, which will allow guaranteed secure transmission of information. Development of quantum computers, which are expected to perform certain computational tasks exponentially faster than classical computers, is in progress.
Loser Applications
With innumerable industrial and scientific applications of quantum theory, some of the ubiquitous laser’s applications may be pointed out as examples of one area of the impact of quantum concepts on science, industry and our daily lives.
Laser (light amplification by stimulated emission radiation) development resulted from the application of quantum mechanics to electronics after World War II. Together with the laser and other advances in the late 1950s, a new discipline in applied physics (Quantum electronics) was created.
A list of the wide uses of the laser points out divergent applications such as medicine, barcode scanners, military applications, garment industry, surveying, laser cooling, laser scanners and printers, compact and optical discs, astronomy, geography, drill and burning holes, as well as myriad of others.
Quantum Theory Gross Domestic Product (GDP)
About 1950, the quantum revolution in the United States fostered a growing high technology (HT) industry that favorably impacted the United States GDP. in 2004, the US Office of Technology Policy analyzed HT employment in the 50 states. Of these states, three states had less than a 2% HT employment level and 13 states were at the I 0% level or greater with Massachusetts at 13%. Employment in HT in 25 states was between 5% and 10% HT.’4 Certainly federal, private and university participation in the evolving science and engineering made this possible. “It is difficult to put a price tag on the amount of current U.S. gross domestic product that would not exist without the discover of the electron and quantum mechanics. But it would likely reach into the trillions of dollar 927 with their consensus about quantum. With quantum theory tools, the end of the century saw the information age and a global economy.
