Abraham Pais > Quotes

“The ultimate unification of weak and electromagnetic interactions has probably not yet been achieved, but a solid beach-head appears to have been established in terms of local non-Abelian gauge theories with spontaneous symmetry breakdown. As a result, it is now widely believed that weak interactions are mediated by massive vector mesons. Current expectations are that such mesons will be observed within the decade. It is widely believed that strong interactions are also mediated by local non-Abelian gauge fields. Their symmetry is supposed to be unbroken so that the corresponding vector mesons are massless. The dynamics of these 'non-Abelian photons' are supposed to prohibit their creation as single free particles. The technical exploration of this theory is in its early stages.”
― Abraham Pais, Subtle Is the Lord: The Science and the Life of Albert Einstein

“All modern work on unification may be said to represent a program of geometrization that resembles Einstein's earlier attempts, although the manifold subject to geometrization is larger than he anticipated and the quantum framework of the program would not have been to his liking.”
― Abraham Pais, Subtle Is the Lord: The Science and the Life of Albert Einstein

“The preceding collection of stories about Einstein the young boy demonstrates the remarkable extent to which his most characteristic personal traits were native rather than acquired.”
― Abraham Pais, Subtle Is the Lord: The Science and the Life of Albert Einstein: Science and Life of Albert Einstein

“he described his own ideals, the desire for fulfillment not just as a theorist but also as an experimental physicist. (In the second respect, he, of course, never matched Newton.)”
― Abraham Pais, Subtle Is the Lord: The Science and the Life of Albert Einstein: Science and Life of Albert Einstein

“He understood that the sources of the gravitational field were not just ponderable matter but also field energy. He realized that gravitational field energy is to be included as a source and that the gravitational field equations were therefore bound to be nonlinear.”
― Abraham Pais, Subtle Is the Lord: The Science and the Life of Albert Einstein

“He had no need to push the everyday world away from him. He just stepped out of it whenever he wished.”
― Abraham Pais, Subtle Is the Lord: The Science and the Life of Albert Einstein: Science and Life of Albert Einstein

“I introduce the subject of fine structure with a mini-calendar of events. ...

Winter 1914-15. Sommerfeld computes relativistic orbits for hydrogen-like atoms. Pashcen, aware of these studies, carefully investigates fine structures, ....

January 6, 1916. Sommerfeld announces his fine structure formula, citing results to be published by Paschen in support of his answer.

February 1916. Einstein to Sommerfeld: "A revelation!"

March 1916. Bohr to Sommerfeld: "I do not believe ever to have read anything with more joy than your beautiful work."

September 1916. Paschen publishes his work, acknowledging Sommerfeld's "indefatigable efforts.”
― Abraham Pais , Inward Bound: Of Matter and Forces in the Physical World

“Promising steps have been made toward grand unification, the union of weak, electromagnetic, and strong interactions in one compact, non-Abelian gauge group. In most grand unifies theories the proton is unstable. News about the proton's fate is eagerly awaited at this time. Superunification, the union of all four forces, is the major goal. Some believe that it is near and that supergravity will provide the answer. Others are not so sure.”
― Abraham Pais, Subtle Is the Lord: The Science and the Life of Albert Einstein

“Weak, electromagnetic, and strong interactions have distinct intrinsic symmetry properties, but this hierarchy of symmetries is not well understood theoretically. Perhaps the most puzzling are the small effects of noninvariance under space reflection and the even smaller effects of noninvariance under space reflection and the even smaller effects of noninvariance under time reversal. It adds to the puzzlement that the latter phenomenon has been observed so far only in a single instance, namely, in the K° - K^-^ system. (These phenomena were first observed after Einstein's death. I have often wondered what might have been his reactions to these discoveries, given his 'conviction' that pure mathematical construction enables us to discover tbe concepts and the laws connectin them'.”
― Abraham Pais, Subtle Is the Lord: The Science and the Life of Albert Einstein

“Special relativity killed the classical dream of using the energy-momentum-velocity relations of a particle as a means of probing the dynamic origins of its mass. The relations are purely kinematic. The classical picture of a particle as a finite little sphere is also gone for good. Quantum field theory has taught us that particles nevertheless have structure, arising from quantum fluctuations. Recently, unified field theories have taught us that the mass of the electron is certainly not purely electromagnetic in nature. But we still do not know what causes the electron to weigh.”
― Abraham Pais, Subtle Is the Lord: The Science and the Life of Albert Einstein