|
Items in cart [0] |
Questions? Call 888-624-8373 |
| ||||||||||||
| Copyright © 2009. National Academy of Sciences. All rights reserved. Terms of Use and Privacy Statement |
Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter.
Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.
OCR for page 435
JERROLD R. ZACHARIAS
January 23, 1 905-July 1 6' 1 986
BY N O RMAN F
. RAMSEY
JERROLD ZACHARIAS MADE important, creative, and lasting con-
tributions to physics, national defense, and education.
He participated in the first molecular beam magnetic reso-
nance experiments; he measured nuclear magnetic moments
and electric quadrupole moments of various nuclei, includ-
ing the proton and cleuteron; he confirmed the anomalous
hyperf~ne separation in atomic hydrogen; and he clevelope
the first commercial atomic clocks. During World War II,
he clevelope(1 radar systems at MIT and nuclear weapons at
Los Alamos. In the years following the war he initiated and
led important national defense studies. As a result of his
creep concerns about science education in the United States,
he initiated numerous fruitful studies to improve it. He
established the Physical Sciences Stucly Committee (PSSC),
which not only made successful recommendations but also
stimulated the production of movies and textbooks. The
PSSC became a model for similar educational reforms in
mathematics ant! most other sciences.
EARLY YEARS
JerroIcl Zacharias was born on January 23, 1905, in Jack-
sonville, Florida. His father, Isaclore, was a lawyer with in-
terests in real estate, and his mother was a taTentecl violin-
435
OCR for page 436
436
BIOGRAPHICAL MEMOIRS
ist. His childhoocI and education are well describer! in an
excellent biography by Jack S. Goicistein.~ {erroIcI had little
interest in music, while his sister, Dorothea, anct his adopted
brother, Beryl Rubenstein, were talentecl musicians. Their
musical mother was consequently less interested in Errol,
who found real companionship in his nurse, Anna Liza
Johnson, who later carecl for Jerroicl's children in New York
City.
JerroIcl's interest in physics began at age four with a fasci-
nation with his grancifather's automobile and continued into
his teens with interests in photography, crystal set raclio,
and the Tom Swift books. Although he received excellent
gracles in high school, including his first physics course,
JerroIcI later complained that he clict not learn much.
Soon after graduation from high school, his family moved
to Riverside Drive in New York City, where JerroIc3 enterer!
Columbia as an engineering student. By his sophomore year,
he fount! physics challenged him more than engineering,
so he changed to a major in mathematics with a minor in
physics. ierrold clic! well as an unclergracluate but later cle-
scribed himself as having been a fraternity playboy with a
generous allowance, a raccoon coat, en cl a Packarc! touring
car. In 1925 as a Columbia undergracluate, ierroIcI, on a
blind (late, met Leona Hurwitz, a delightful, serious biol-
ogy major at Barnard. They married two years later. Leona
remained his lifelong companion and became the mother
of Susan en c] Johanna.
After graduating, Errol enterer! Columbia graduate school
en cl began research with Shirley Quimby in solid state phys-
ics, a barely recognized research f~elcl at that time. Qulmby
suggested the problem of measuring the stress-strain rela-
tionship (Young's mocluTus) and internal friction in crystals
of nickel by studying their vibrations. Zacharias discovered
an unexpected diminution of internal friction of the crys-
OCR for page 437
JERROLD R. ZACHARIAS
437
tats at the Curie temperature, where their magnetic proper-
ties also change dramatically.
RESEARCH AT COLUMBIA
JerroIcl Zacharias completed his thesis research in 1931-
the middle of the great depression, when few jobs were
available. He succeecled in obtaining an appointment as a
tutor at Hunter College at a salary of $2,000 per year and
with a heavy teaching schedule.
Zacharias was an excellent teacher but was eager to re-
turn to experimental research as well, so, in adclition to his
Hunter teaching duties, he soon arranger! to work with I. T.
Rabi of Columbia University. He spent his free evenings
ant! weekends in Rabi's atomic beam laboratory as an un-
paicl research associate. Rabi had invented an atomic beam
methoc! for measuring the magnetic moments of nuclei by
their interaction with the magnetic moment of the elec-
tron, which affecter! how the atom would be (leflectec! by
an inhomogeneous magnetic fielcI. With his first graduate
student, Victor Cohen, Rabi was applying this method to
the measurement of the nuclear magnetic moments of so-
clium and cesium. Zacharias was especially interested in sim-
pler fundamental atoms, so he joined with Rabi and Jerome
M. B. Kellogg, a young Columbia instructor newly arrived
from Towa, on the more difficult task of measuring the nuclear
magnetic moments of hydrogen and deuterium. They con-
firmect Otto Stern's earlier observation that the magnetic
moment of the proton was much larger than the theoreti-
cally expected value of one nuclear magneton. These ob-
servations provident the first indications that the proton hacI
a complex internal structure. Later Zacharias and his asso-
ciates improved their results by using the new zero moment
method and then further mortifies! their apparatus to mea-
OCR for page 438
438
BIOGRAPHICAL MEMOIRS
sure the signs of the proton and deuteron magnetic mo-
ments.
In the summer of 1937, Zacharias, S. MilIman, P. Kusch,
and Rabi measured the magnetic moments of inclium and
gallium anc! found a small contribution to the deflection
patterns from the thermally excited higher energy states.
By studying these contributions they couict also measure
the nuclear quacirupole moments of these nuclei. With char-
acteristic humor, ~erroIcl clescribed this period! of research
as indium summer. T had the good fortune to join the Co-
lumbia atomic beam laboratory at this time and to work on
this experiment as an apprentice. It was a great experience
and T Earned much, ranging from apparatus design and
vacuum techniques to ciata analysis and theoretical prin-
ciples. Although Jerrold had not yet acquired his fame in
science education, he was a talentecl teacher. He taught me
one particularly memorable lesson. T hacl just given what
seemed to be a highly successful colloquium and ferrous
asked me to hanc! him my third slide. Instead of the ex-
pected question about its contents, he dramatically broke
the sTicle over the edge of the lecture table en c! said, "Don't
ever again show a slicle that cannot be react from the back
of the room" a painful lesson ~ have never forgotten.
In 1937 {erroIcI was appointee! assistant professor at Hunter
College and Leona obtainer! her Ph.D. and an appoint-
ment as instructor at the Columbia College of Physicians
en c! Surgeons.
Also in 1937 the research at Columbia was revolutionized
by Rabi's invention of the magnetic resonance method. The
first successful experiment with this methoc! was by Rabi,
Miliman, Kusch, en cl Zacharias. This experiment was the
forerunner of many different kinds of resonance experi-
ments, including nuclear magnetic resonance and paramag-
netic resonance. The first resonance experiment was soon
OCR for page 439
JERROLD R. ZACHARIAS
439
followed by the experiments of Kellogg, Rabi, Ramsey, and
Zacharias, which not only obtained accurate values for the
proton and deuteron magnetic moments but also discov-
ered the electric quadrupole moment of the deuteron, which
in turn showed the existence of a new kind of force a
tensor force—between the proton and neutron.
Zacharias then turned his attention to measuring the
magnetic moment of 40K, since some theorists had predicted
that its unusually long lifetime might be associated with a
large nuclear magnetic moment. The measurement was suc-
cessful though difficult because only one atom in 10,000 of
natural potassium is 40K. In 1940 ~errold and T were invited
to give talks on our magnetic and electric dipole moment
measurements at a meeting of the American Physical Soci-
ety in Seattle, Washington, so Jerrold drove my new wife
and me cross country to Seattle and then back to Glacier
Park where we were joined by l~eona. The trip was scientifi-
cally and scenically exciting but politically distressing since
the Nazis were moving through France almost as rapidly as
we moved across the United States. It appeared that the
war would soon be upon us.
THE WAR YEARS
Our fears soon proved to be valid; within the next four
months Zacharias, Rabi, and T had moved to the MIT Ra-
diation Laboratory, where we worked on microwave radar.
Zacharias's first task at MTT was to establish a lab on the
MIT roof and build a radar system there capable of detect-
ing distant objects. His success led to his being asked by the
Navy to install a radar set on a destroyer. When this was
successfully completed, Zacharias became the Radiation
Laboratory representative at the Bell Telephone Laborato-
ries in Whippany, New Jersey, during the development of a
production model for the MIT 10-cm night fighter radar.
OCR for page 440
440
BIOGRAPHICAL MEMOIRS
He then went to England to adapt the Oboe blind bombing
system from long wavelengths to microwaves. He returned
to the Racliation Laboratory to head the Transmitter Com-
ponents Division, and in the spring of 1945 he accepted
the offer of a full professorship at MTT while remaining on
leave to continue his racier research.
Zacharias left MIT to go to Los Alamos a few months
before the end of the war to head the Orcinance Engineer-
ing Division, a position vacated by Captain (later Aclmiral)
W. S. Parsons, who hac! left for the Pacific isTanct of Tinian.
That division later became the Z division, which evolved
into the Sanclia National Laboratories.
NUCLEAR SCIENCE, ATOMIC BEAMS, AND ATOMIC CLOCKS
At the war's end Jerrold Zacharias returned to MTT as
professor of Physics en c] director of the newly established
Laboratory for Nuclear Science en cl Engineering. He quickly
arranged for financial support from the newly established
Office of Naval Research en c! organized a strong research
staff, inclucling B. Rossi, I. G. Trump, M. Deutsch, R. I. Van
c3 eGraff, R. D. Evans, I. A. Getting, V. F. Weisskopf, M.
Benedict, and C. D. Coryell. Zacharias was also an MIT
representative on the Initiatory University Group en cl later
the Associates! Universities, Inc. (AUl), which establishecI
Brookhaven National Laboratory.
Zacharias and his associates establisher! a vigorous and
effective atomic beam research laboratory. They indepen-
dently confirmed! that the experimental value of the atomic
hydrogen hyperfine structure disagreed with the theoreti-
cal value, a disagreement that stimulated the clevelopment
of relativistic quantum electroclynamics. They measurer] a
number of nuclear spins ant! magnetic moments and for
the first time detectecl a nuclear magnetic octupole mo-
ment.
OCR for page 441
JERROLD R. ZACHARIAS
441
Zacharias at this time became interested in developing
atomic clocks en c! pursued two versions concurrently. One
was a cesium atomic beam clock using my separates! oscilIa-
tory fierce methoct,2 well engineered for reliability ant] com-
mercial applications, including a source and vacuum sys-
tem that could be operated for years rather than hours. He
cooperated with the National Company in developing a com-
mercial clock known as the Atomichron. The availability of
this highly successful cesium atomic beam clock contrib-
utec3 greatly to the adoption of atomic time and to the
international definition of the second! as 9,192,631,770 os-
cilIations of the cesium atom.
His other version had the potential for much greater ac-
curacy but the risk of total failure. A very slow beam of
atomic cesium was directecI upward and allowed to fall as a
fountain, with separates! oscillatory field excitation on the
way up and clown. The half second required for the roundtrip
in the fountain was approximately fifty times greater than
that for an atom to traverse the oscillatory field region of a
conventional atomic beam apparatus, so the resonance wraith,
by the Heisenberg uncertainty principle, would be fifty times
narrower with corresponclingly increased clock accuracy.
Despite valiant efforts by Zacharias ant! his associates, the
fountain experiment failed because the numbers of ultra-
sIow atoms in the beam were far below theoretical predic-
tions, probably clue to scattering in the nonequilibrium re-
gion between the slits. It is of interest to note that thirty
years later, in 1989, Steven Chu3 succeeded in making an
atomic fountain by using the new laser cooling techniques
to produce ultra-sIow atoms. The atomic fountain with laser
cooling is now one of the most promising prospects for
increasing the accuracy of clocks and frequency stanciarcts.
OCR for page 442
442
BIOGRAPHICAL MEMOIRS
DEFENSE STUDIES
As the CoIcl War intensified in the late 1940s, Zacharias
became involved in defense studies. The first of these was
Project Lexington, commissioned by the Atomic Energy
Commission in 1948 to study the feasibility of nuclear-pow-
erecI aircraft. Although deputy director of the study, Zacharias
was frustrates! by its being limited to the narrow question
of the feasibility of nuclear-powerecl aircraft to the exclu-
sion of the broacler questions of their practicality ant! clesir-
ability. He learner! from this experience that later studies
that he organizer! or directed must have broadly clefined
· ~
missions.
For the Navy he clirectect Project Hartwell, on the threat
by Soviet submarines. At his insistence the mission was so
broadly definecl that the title of the final report was A Re-
port on the Security of Overseas Transport. The conclusions
included recommendations for a new high-speec! merchant
fleet and modernization of port ant! cargo facilities as well
as recommendations for submarine detection.
In it951 Zacharias served as associate director of Project
Charles, which was established to make recommendations
on the air defense of the North American continent. The
project recommencled tests of an experimental system of
radars coupled through high-speecI digital computers ant!
the establishment of a new laboratory (Lincoln Laboratory)
to continue research on this problem. Jerrold later directed
a 1952 I~incoin Laboratory study of air (lefense that recom-
menclect establishment of the DEW (distant early warning)
line, a chain of huge radars stretched across the Arctic and
coupled to high-speec! computers to detect approaching
missiles. In 1955 Zacharias ctirectect Project Lamp Light to
study fleet ant! air defense.
Many years later, during the Vietnam War, Zacharias di-
OCR for page 443
JERROLD R. ZACHARIAS
443
rected one more Department of Defense study, this time on
means for preventing the infiltration of men and materials
across the demilitarized zone between North and South Viet-
nam. The study recommended an electronic barrier as an
alternative to air bombardment.
EDUCATION REFORM
In 1955, at the age of fifty and after ten years of service,
Zacharias retired as director of MIT's Laboratory for Nuclear
Science, and a year later he terminated his atomic beam
research to devote himself to his newest interest—educa-
tion reform, especially in the sciences. He deeply believed
that the United States would suffer in the future from the
inadequacy of its science education and that "in order to
save our democracy, we've got to It the neonle who
r - -r
vote."
Although his initial plans emphasized the development
of a series of educational physics films, he approached the
problems of education in the same broad manner that had
been so successful in his defense studies. With the support
of the National Science Foundation, he assembled a bril-
liant array of individuals, including research physicists, teach-
ers, scholars, writers, and motion picture directors, to form
the Physical Sciences Study Committee (PSSC). The com-
mittee agreed that an entirely new approach to physics edu-
cation was required, including new textbooks, laboratory
kits to provide firsthand experience with simple apparatus,
films, supplementary reading materials, and teacher train-
ing. The U.S. public reaction to the spectacular success of
the Russian Sputnik in 1957 added urgency to the PSSC
project. Talented new recruits joined the PSSC, which sub-
sequently was well supported by the NSF and private orga-
nizations such as the Alfred P. Sloan Foundation.
Nearly sixty films were eventually produced by the PSSC
OCR for page 444
444
BIOGRAPHICAL MEMOIRS
with scientists rather than actors en c! with emphasis on fun-
damental principles en c! on hoIcling student interest. A text-
book was written and widely a(loptecT, along with teaching
aids and new laboratory materials, including simple but in-
formative experiments for schools with low budgets. Since
good teachers are essential to the success of such a pro-
gram, special summer institutes for teacher training were
established.
The PSSC influence extencled far beyond the teaching of
high school physics in the United States. In universities
physics courses were improver! to meet the changed knowI-
ecige and expectations of entering students with PSSC ex-
perience. The PSSC also server! as a moclel for similar stucI-
ies and curriculum changes in mathematics and other
sciences. The PSSC was followed with great interest abroad,
en c! its textbooks were translated into more than twelve
languages.
Zacharias also became interested! in elementary school
science problems and establisher! Educational Services, Inc.
(ESI), under which a study was initiated to develop a sci-
ence program for elementary schools. Eventually, this hacI
a large impact on American education. His meetings ant!
discussions about the problems of science education in Af-
rica lecl to the African nations cooperating to establish a
Science Education Program for Africa (SEPA).
Zacharias's eclucational interests were not limiter! to sci-
ence. He also encourageec! EST to establish the influential
Social Studies Curriculum Program and the Negro College
Program.
A triple bypass coronary operation in 1977 only siowecl
Zacharias as he continued to push for education reform. At
the same time, his deep concerns about the threat of nuclear
war tell him to coauthor a thoughtful essay titled Common
OCR for page 445
lERROLD R. ZACHARIAS
445
Sense and Nuclear Peace. He died from coronary artery dis-
ease on July 16, 1986, at the age of eighty-one.
HONORS AND AWARDS
Jerrold Zacharias received many honors and awards, in-
cluding election to the National Academy of Sciences in
1~957 and to the American Academy of Arts and Sciences.
He was a fellow of the American Physical Society, American
Association for the Advancement of Science, and the Insti-
tute of Electrical and Electronic Engineers. He was an insti-
tute professor at MIT and a member of the American Asso-
ciation of Physics Teachers (AAPT) and the President's
Science Advisory Committee. The U.S. government awarded
him the President's Certificate of Merit and the Depart-
ment of Defense Certificate of Appreciation, its highest ci-
vilian honor. He received the AAPT's Oersted Medal for his
contributions to teaching, the National Teachers Associa-
tion Citation for Distinguished Service to Science Educa-
tion, and the T. I. Rabi Award "for technical excellence and
outstanding contributions in the fields relating to atomic
and molecular frequency standards." Zacharias also received
honorary degrees from Tufts University, Oklahoma City
University, St. Lawrence University, Lincoln University, and
Brandeis University.
SCIENCE, DEFENSE, AND EDUCATION
Science, national defense, and education were all greatly
changed by ~errold Zacharias. His work on the first molecu-
lar beam magnetic resonance experiments led the way for
later magnetic resonance techniques, such as nuclear mag-
netic resonance (NMR) and magnetic resonance imaging
(MRI). He and his associates measured numerous nuclear
spins and magnetic moments and discovered the quadru-
pole moment of the deuteron, which implied the existence
OCR for page 446
446
BIOGRAPHICAL MEMOIRS
of a new kind of nuclear force. His clevelopment of the first
commercial atomic cesium beam clock eventually lect to the
international adoption of the atomic cesium oscillations as
the definition of the second.
Zacharias's wartime work on racier increased the reliabil-
ity, versatility, and effectiveness of racier. The studies he
initiated cluring the coict war contributed importantly to
national defense.
The teaching of physics in many elementary and seconcl-
ary schools was greatly changed by studies, such as PSSC,
initiated by Zacharias and by new movies, classroom materi-
als, and teacher training programs. The success of these
programs in turn stimulatecI similar education reforms in
other sciences and in other countries.
In his scientific research his development of atomic clocks,
and his defense and eclucational projects, {erroIcI Zacharias
was not cleterrecI by formiciable obstacles. He attacked for-
midable problems with enthusiasm en c! determination. His
positive anti constructive attitude is well characterized by
the remark of I. I. Rabi: "Dr. Zacharias is a man who, if he
were to discuss the weather, would finish not by just talking
about it, but he would be cloing something about it."
NOTES
1. J. S. Goldstein. A Different Sort of Time: The Life of Jerrold R.
Zacharias Cambridge, Mass.: MIT Press, 1992. This excellent biog-
raphy is the source of much of my information about Zacharias's
full and varied life and provides a much fuller account than can be
presented in a brief memoir.
2. N. F. Ramsey. Molecular beam resonance method with sepa-
rated oscillatory fields. Phys. Rev. 78 ( 1950) :695.
3. M. Kasevich, E. Riis, S. Chu, and R. S. DeVoe. RF spectros-
copy in an atomic fountain. Phys. Rev. Letters (1989~:612.
OCR for page 447
JERROLD R. ZACHARIAS
SELECTED BIBLIOGRAPHY
1933
447
The temperature of Young's modulus for nickel. Phys. Rev. 44:116-
12.
With A. Dingwell and S. Siegel. The contamination of nickel crys-
tals grown in a molybdenum resistance furnace. Trans. Am. Electrochem.
Soc. 63:395-400.
1934
With I. I. Rabi and {. M. B. Kellogg. The magnetic moment of the
proton. Phys. Rev. 46:157-63.
With I. I. Rabi and J. M. B. Kellogg. The magnetic moment of the
deuteron. Phys. Rev. 46:163.
1936
With I. I. Rabi and T. M. B. Kellogg. The sign of the magnetic
moment of the proton. Nature 137:658.
With J. M. B. Kellogg and I. I. Rabi. The gyromagnetic properties of
the hydrogens. Phys. Rev. 50:472.
1937
With S. Millman. Signs of the nuclear magnetic moments of Li7,
Rb85, and Cs~35. Phys. Rev. 51:1049.
1938
With I. I. Rabi, S. Millman, and P. Kusch. New method of measur-
ing nuclear magnetic moment. Phys. Rev. 53:318.
With S. Millman and I. I. Rabi. On the nuclear moments of indium.
Phys. Rev. 53:384-91.
With I. I. Rabi, S. Millman, and P. Kusch. Magnetic moments of
3Li6, 3Li7, and gFi9. Phys. Rev. 53:495.
1939
With I. I. Rabi, S. Millman, and P. Kusch. The molecular beam
resonance method for measuring nuclear magnetic moments. Phys.
Rev. 55:728.
With J. M. B. Kellogg, I. I. Rabi, and N. F. Ramsey. The magnetic
OCR for page 448
448
BIOGRAPHICAL MEMOIRS
moments of the proton and deuteron. The radio frequency spec-
trum of H2 in various magnetic fields. Phys. Rev. 56:728.
1940
With I. M. B. Kellogg, I. I. Rabi, and N. F. Ramsey. The electric
quadrupole moment of the deuteron. Phys. Rev. 57:677-95.
1942
The nuclear spin and magnetic moment of K40. Phys. Rev. 61:270.
1947
With D. E. Nagle and R. S. Julian. The atomic hyperfine structure
of hydrogen. Phys. Rev. 72:971.
1949
With L. Davis~and D. E. Nagle. Atomic beam magnetic resonance
experiments with Na22, K40, CSI35 and Cs~37 Phys Rev 76:1068
1957
Today's science tomorrow's promise. Technol. Rev. (July) :501.
With R. D. Haun. Stark effects in cesium-133 hyperfine structure.
Phys. Rev. 107:107-9.
1961
Team approach to education. Am. f. Phys. 29:347-49.
1966
With O Cope. Medical Education Revisited: Report on the Endicott House
Summer Study on Education. Philadelphia: Lippincott.
Undergraduate education and atomic clocks. R. L. E. 1946+20, MIT.
1972
The common reader. Nat. Elem. Prin. 51:73-75.
1975
Testing in the schools: a help or a hindrance? Prospects 5:33-41.
The trouble with IQ tests. Nat. Elem. Prin. 54:23-29.
OCR for page 449
JERROLD R. ZACHARIAS 449
1980
The case of the missing scientists. Nat. Elem. Prin. 59:14-17.
1983
With M. Gordon and S. R. Davis. Common sense and nuclear peace.
Bull. At. Sci. 39 (April).
OCR for page 450
Representative terms from entire chapter:
nuclear magnetic
