Customer Reviews (8) 
Spin: from a spectroscopic anomaly to the gates to quantum field theory
Textbooks necessarily present the laws of physics as a fait accompli, placing the primary emphasis on mathematical formalism, with only a few carefully selected experiments as empirical touchstones.Sin-itiro Tomonaga, who along with Richard Feynman and Julian Schwinger won the 1965 Nobel Prize in physics for his work in quantum electrodynamics, recounts the evolution of the concept of spin in much greater detail that a textbook could ever afford to--and on a human scale.Central to Tomonaga's story is the limit of human imagination and daring--even among the most brilliant theoretical physicists.He begins his story with the early years of quantum theory and its attempt to model atomic spectra.Only after earlier models proved unable to explain the details of atomic spectroscopy did the idea of electron spin acquire the impetus to move it forward--which occurs in the person of Wolfgang Pauli.
Tomonaga next introduces Pauli's addition of a spin term to the Schrodinger equation, a formulation that was soon followed by that of Paul Dirac's fully relativistic equation.The formulation of Pauli was published in 1927, while that of Dirac was published in 1928, with Dirac's work mirroring Pauli's work in many important respects--the inclusion of the Pauli matrices in particular.In addition to Pauli's significant influence on Dirac's work, the author observes that Pauli, in turn, was astonished at Dirac's achievement--praising Dirac's thought processes as "acrobatic".Despite the magnitude of his achievement however, Dirac appeared somewhat reticent to fully exploit his discovery, demurring from applying his newfound formulation to the hydrogen atom for fear that it might fall short.Tomonaga observed with regard to Dirac that:
"Because of his immense confidence in the correctness of his theory, even a 1 percent fear that his expectation might be crushed would perhaps also have been very frightening.This sentiment is as illogical as that of a sick person who does not want to consult a doctor for fear of being told he has cancer.However, even theoretical physicists often become prisoners of such irrationally twisted sentiment."
These and other keen observations on the evolution and substance of spin await the reader of Tomonaga's insightful book!
Clear and Pretty
What a beautiful book!It's derived from a collection of Tomonaga's lectures, and his love of simple statements and clear style really make them flow.I came away from this book understanding much more about field quantization, isospin, and the Thomas theory than I ever had before.
Oka's translation is clear and colloquial -- a justified act of love.And as a renowned physicist in his own right, he ensured that the physics was not mangled in translation -- the prose about the physics is clear and correct (at least to my understanding).I don't know if he had to clean up any equations, but I didn't notice any typos in them either.Also, this may be a minor point, but I thought the equation numbering scheme with the subscripts was really helpful.
This book is not intended for general audiences; if the reader isn't familiar with Hamiltonians or quantum mechanics he will gain relatively little from it.
From the clouds to the ground
A story about the hardships involved in the beginning of the 1900s with the birth of Quantum Mechanics.As a physicist one only hears about the great physicists in text books with theory's, experiments, and equations named after them.One even wonders if these scientists were humans or superhumans because colleagues speak of them so 'godly'.Tomonaga brings these great physicists 'down' to earth and describes the atmosphere at the time of incredible struggle.He brings to the forefront the pains the scientists went through,the frictions between mentor and apprentice, the battle to look for a pattern in the data, and the incredible enlightenment accompanied by the resolution of a problem.
This story is not simply of spin.It is also about LIFE, finding meaning in the struggle.Tomonaga spells out for you the hardships involved for every scientist working on problems; thinking outside the box, the everlasting obstacle.But it is in this where nature speaks truth as Tomonaga describes.
For scientists and laypeople alike, this story is about people trying to figure out nature, quantum nature.The scientists are not superhumans, filled with the spirits or god(s).Real people who really struggled, who cried and cursed to find a solution.
A great book about the great human stuggle written by one who solved a great problem.
A Wonderful Overview
This is a series of twelve lectures of the physics of the spin angular momentum, and essentially quantum mechanical notion allied only metaphorically to the macroscopic world. Not, perhaps, in all its implications-the theory of ferromagnetism gets short shrift- but in its essential physical aspects.
The topics include spectroscopy, Thomas precession (which one of my undergraduate professors could never fully believe), relativistic quantum mechanics, and statistical physics. It's all very rewarding.
Expounding on "the wide range of physics with varying degrees of difficulty" that understanding spin requires, the translator's preface quotes the Feynman Lectures, "It appears to be one of the few places in physics where there is a rule which can be stated very simply, but for which no one has found a simple and easy explanation. The explanation is deep down in relativistic quantum mechanics. This probably means that we do not have a complete understanding of the fundamental principle involved." The translator, Takeshi Oka, is a professor at the Enrico Fermi Institute at the University of Chicago, and the introduction is from 1996. We can trust his assessment of the situation and conjecture that it probably hasn't changed much since then.
The approach is collegial rather than academic and to anyone with a modest physics or mathematics background (e.g., someone with physics minor or an elementary understanding of vectors and differential equations), the treatments should be sufficiently accessible to use as an introduction. For an educated reader with no mathematical background, I think only lectures 9 and 11 will be a total wash, although another six will be rough going (but. I'd hope, rewarding).
Although the lectures aren't overly mathematical, at least in the sense that a physicist would use the term, the lectures contain mathematics. Some equations are shown, others swiftly derived and one or two proofs are introduced. Many times, Tomonaga introduces ideas to explain why a particular aspect of the mathematics, i.e., spinors, was needed or created. The intuitive descriptions of the mathematics and intimate explanations of how ideas were derived are invaluable for understanding the nature of spin.
a truly beautiful mind :)
Mr. Tomonaga deserves that expression more than others because of his sensitivity and sweetness (if such things can be said about physicists ;) .. the book speaks for itself and is a 'must read' for anyone interested in physics or the history of physics :) enuf said ;)
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