Sheldon Lee Glashow (; born December 5, 1932)
is a Nobel Prize winning American theoretical
physicist.
He is the Metcalf Professor of Mathematics
and Physics at Boston University and Eugene
Higgins Professor of Physics, Emeritus, at
Harvard University, and is a member of the
Board of Sponsors for the Bulletin of the
Atomic Scientists.
== Birth and education ==
Sheldon Lee Glashow was born in New York City,
to Jewish immigrants from Russia, Bella (née
Rubin) and Lewis Gluchovsky, a plumber.
He graduated from Bronx High School of Science
in 1950.
Glashow was in the same graduating class as
Steven Weinberg, whose own research, independent
of Glashow's, would result in Glashow, Weinberg,
and Abdus Salam sharing the 1979 Nobel Prize
in Physics (see below).
Glashow received a Bachelor of Arts degree
from Cornell University in 1954 and a Ph.D.
degree in physics from Harvard University
in 1959 under Nobel-laureate physicist Julian
Schwinger.
Afterwards, Glashow became a NSF fellow at
NORDITA and joined the University of California,
Berkeley where he was an associate professor
from 1962 to 1966.
He joined the Harvard physics department as
a professor in 1966, and was named Eugene
Higgins Professor of Physics in 1979; he became
emeritus in 2000.
Glashow has been a visiting scientist at CERN,
and professor at Aix-Marseille University,
MIT, Brookhaven Laboratory, Texas A&M, the
University of Houston, and Boston University.
== Research ==
In 1961, Glashow extended electroweak unification
models due to Schwinger by including a short
range neutral current, the Z0.
The resulting symmetry structure that Glashow
proposed, SU(2) × U(1), forms the basis of
the accepted theory of the electroweak interactions.
For this discovery, Glashow along with Steven
Weinberg and Abdus Salam, was awarded the
1979 Nobel Prize in Physics.
In collaboration with James Bjorken, Glashow
was the first to predict a fourth quark, the
charm quark, in 1964.
This was at a time when 4 leptons had been
discovered but only 3 quarks proposed.
The development of their work in 1970, the
GIM 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 — an anomaly — where classical
field theory symmetries fail to carry over
into the quantum theory.
In 1973, Glashow and Howard Georgi proposed
the first grand unified theory.
They discovered how to fit the gauge forces
in the standard model into an SU(5) group,
and the quarks and leptons into two simple
representations.
Their theory qualitatively predicted the general
pattern of coupling 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 of Baryon number is inexact,
that the proton is unstable.
This work was the foundation for all future
unifying work.
Glashow shared the 1977 J. Robert Oppenheimer
Memorial Prize with Feza Gürsey.
== Criticism of superstring theory ==
Glashow is a skeptic of superstring theory
due to its lack of experimentally testable
predictions.
He had campaigned to keep string theorists
out of the Harvard physics department, though
the campaign failed.
About ten minutes into "String's the Thing",
the second episode of The Elegant Universe
TV series, he describes superstring theory
as a discipline distinct from physics, saying
"...you may call it a tumor, if you will...".
== Personal life ==
Glashow is married to the former Joan Shirley
Alexander.
They have four children.
Lynn Margulis was Joan's sister, making Carl
Sagan his former brother-in-law.
Daniel Kleitman, who was another doctoral
student of Julian Schwinger, is also his brother-in-law,
through Joan's other sister, Sharon.
In 2003 he was one of 22 Nobel Laureates who
signed the Humanist Manifesto.
Glashow has described himself as a "practising
atheist" and he is a Democrat.
== Works ==
The charm of physics (1991) ISBN 0-88318-708-6
From alchemy to quarks: the study of physics
as a liberal art (1994) ISBN 0-534-16656-3
Interactions: a journey through the mind of
a particle physicist and the matter of this
world (1988) ISBN 0-446-51315-6
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) ISBN 0-915692-31-7
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) ISBN 3-7643-3105-4
"Desperately Seeking Superstrings?" with Paul
Ginsparg in Riffing on Strings: Creative Writing
Inspired by String Theory (2008) ISBN 978-0-9802114-0-5
== See also ==
List of Jewish Nobel laureates
GIM mechanism
