In collaboration withJames Bjorken, Glashow was the first to predict a fourth quark, thecharm quark, in 1964. This was at a time when 4leptons had been discovered but only 3 quarks proposed. The development of their work in 1970, theGIM mechanism showed that the two quark pairs: (d.s), (u,c), would largely cancel out flavor changing neutral currents, which had been observed experimentally at far lower levels than theoretically predicted on the basis of 3 quarks only. The prediction of the charm quark also removed a technical disaster for any quantum field theory with unequal numbers of quarks and leptons — ananomaly — where classical field theory symmetries fail to carry over into the quantum theory.
In 1973,[10] Glashow andHoward Georgi proposed the firstgrand unified theory. They discovered how to fit the gauge forces in thestandard model into anSU(5) Lie group group, and the quarks and leptons into two simple representations. Their theory qualitatively predicted the general pattern ofcoupling constant running, with plausible assumptions, it gave rough mass ratio values between third generation leptons and quarks, and it was the first indication that the law ofBaryon number is inexact, that theproton is unstable. This work was the foundation for all future unifying work.
Glashow is a skeptic ofsuperstring theory due to its lack of experimentally testable predictions. He had campaigned to keep string theorists out of theHarvard physics department, though the campaign failed.[13] About ten minutes into "String's the Thing", the second episode ofThe Elegant Universe TV series, he describes superstring theory as a discipline distinct from physics, saying "...you may call it a tumor, if you will...".[14]
Professor Glashow's KHC PY 101 Energy class, at Boston University's Kilachand Honors College (Spring 2011)
Glashow is married to Joan Shirley Alexander. They have four children.[5]Lynn Margulis was Joan's sister, makingCarl Sagan his former brother-in-law.Daniel Kleitman, who was another doctoral student ofJulian Schwinger, is also his brother-in-law, through Joan's other sister, Sharon.
In 2003, he was one of 22 Nobel Laureates who signed theHumanist Manifesto.[15] Glashow has described himself as a "practisingatheist" and a Democrat.[16]
From Alchemy to Quarks: The Study of Physics as a Liberal Art (1994)ISBN0-534-16656-3
Interactions: A Journey Through the Mind of a Particle Physicist and the Matter of this World (1988)ISBN0-446-51315-6
First Workshop on Grand Unification: New England Center, University of New Hampshire, April 10–12, 1980 edited with Paul H. Frampton and Asim Yildiz (1980)ISBN0-915692-31-7
Third Workshop on Grand Unification, University of North Carolina, Chapel Hill, April 15–17, 1982 edited with Paul H. Frampton and Hendrik van Dam (1982)ISBN3-7643-3105-4
^"[T]here ain't no experiment that could be done nor is there any observation that could be made that would say, `You guys are wrong.' The theory is safe, permanently safe." He also said, "Is this a theory of Physics or Philosophy? I ask you"NOVA interviewArchived 2011-08-30 at theWayback Machine
^"Notable Signers".Humanism and Its Aspirations. American Humanist Association. Archived fromthe original on October 5, 2012. RetrievedOctober 2, 2012.
^Sheldon Glashow, Nobel Prize in Physics for the Electroweak Theory . La Vanguardia, 20 June 2017, raed.academy/wp-content/uploads/2017/06/Sheldon-Lee-Glashow-contraLVeng.pdf.
