My father, Ju Chin
Chu, came to the United States in 1943 to continue his education
at the Massachusetts Institute of Technology in chemical
engineering, and two years later, my mother, Ching Chen Li,
joined him to study economics. A generation earlier, my mother's
grandfather earned his advanced degrees in civil engineering at
Cornell
while his brother studied physics under Perrin at the Sorbonne
before they returned to China. However, when my parents married
in 1945, China was in turmoil and the possibility of returning
grew increasingly remote, and they decided to begin their family
in the United States. My brothers and I were born as part of a
typical nomadic academic career: my older brother was born in
1946 while my father was finishing at MIT, I was born in St.
Louis in 1948 while my father taught at Washington
University, and my younger brother completed the family in
Queens shortly after my father took a position as a professor at
the Brooklyn Polytechnic Institute.
In 1950, we settled in Garden City, New York, a bedroom community
within commuting distance of Brooklyn Polytechnic. There were
only two other Chinese families in this town of 25,000, but to
our parents, the determining factor was the quality of the public
school system. Education in my family was not merely emphasized,
it was our raison d'être. Virtually all of our aunts and
uncles had Ph.D.'s in science or engineering, and it was taken
for granted that the next generation of Chu's were to follow the
family tradition. When the dust had settled, my two brothers and
four cousins collected three MDs, four Ph.D.s and a law degree. I
could manage only a single advanced degree.
In this family of accomplished scholars, I was to become the
academic black sheep. I performed adequately at school, but in
comparison to my older brother, who set the record for the
highest cumulative average for our high school, my performance
was decidedly mediocre. I studied, but not in a particularly
efficient manner. Occasionally, I would focus on a particular
school project and become obsessed with, what seemed to my
mother, to be trivial details instead of apportioning the time I
spent on school work in a more efficient way.
I approached the bulk of my schoolwork as a chore rather than an
intellectual adventure. The tedium was relieved by a few courses
that seem to be qualitatively different. Geometry was the first
exciting course I remember. Instead of memorizing facts, we were
asked to think in clear, logical steps. Beginning from a few
intuitive postulates, far reaching consequences could be derived,
and I took immediately to the sport of proving theorems. I also
fondly remember several of my English courses where the assigned
reading often led to binges where I read many books by the same
author.
Despite the importance of education in our family, my life was
not completely centered around school work or recreational
reading. In the summer after kindergarten, a friend introduced me
to the joys of building plastic model airplanes and warships. By
the fourth grade, I graduated to an erector set and spent many
happy hours constructing devices of unknown purpose where the
main design criterion was to maximize the number of moving parts
and overall size. The living room rug was frequently littered
with hundreds of metal "girders" and tiny nuts and bolts
surrounding half-finished structures. An understanding mother
allowed me to keep the projects going for days on end. As I grew
older, my interests expanded to playing with chemistry: a friend
and I experimented with homemade rockets, in part funded by money
my parents gave me for lunch at school. One summer, we turned our
hobby into a business as we tested our neighbors' soil for
acidity and missing nutrients.
I also developed an interest in sports, and played in informal
games at a nearby school yard where the neighborhood children met
to play touch football, baseball, basketball and occasionally,
ice hockey. In the eighth grade, I taught myself tennis by
reading a book, and in the following year, I joined the school
team as a "second string" substitute, a position I held for the
next three years. I also taught myself how to pole vault using
bamboo poles obtained from the local carpet store. I was soon
able to clear 8 feet, but was not good enough to make the track
team.
In my senior year, I took advanced placement physics and
calculus. These two courses were taught with the same spirit as
my earlier geometry course. Instead of a long list of formulas to
memorize, we were presented with a few basic ideas or a set of
very natural assumptions. I was also blessed by two talented and
dedicated teachers.
My physics teacher, Thomas Miner was particularly gifted. To this
day, I remember how he introduced the subject of physics. He told
us we were going to learn how to deal with very simple questions
such as how a body falls due to the acceleration of gravity.
Through a combination of conjecture and observations, ideas could
be cast into a theory that can be tested by experiments. The
small set of questions that physics could address might seem
trivial compared to humanistic concerns. Despite the modest goals
of physics, knowledge gained in this way would become collected
wisdom through the ultimate arbitrator - experiment.
In addition to an incredibly clear and precise introduction to
the subject, Mr. Miner also encouraged ambitious laboratory
projects. For the better part of my last semester at Garden City
High, I constructed a physical pendulum and used it to make a
"precision" measurement of gravity. The years of experience
building things taught me skills that were directly applicable to
the construction of the pendulum. Ironically, twenty five years
later, I was to develop a refined version of this measurement
using laser cooled atoms in an atomic fountain
interferometer.
I applied to a number of colleges in the fall of my senior year,
but because of my relatively lackluster A-average in high school,
I was rejected by the Ivy League schools, but was accepted at
Rochester. By comparison, my older brother was
attending Princeton, two cousins were in Harvard and a third
was at Bryn Mawr. My
younger brother seemed to have escaped the family pressure to
excel in school by going to college without earning a high school
diploma and by avoiding a career in science. (He nevertheless got
a Ph.D. at the age of 21 followed by a law degree from Harvard
and is now a managing partner of a major law firm.) As I prepared
to go to college, I consoled myself that I would be an anonymous
student, out of the shadow of my illustrious family.
The Rochester and Berkeley
Years
At Rochester, I came with the same emotions as many of the
entering freshman: everything was new, exciting and a bit
overwhelming, but at least nobody had heard of my brothers and
cousins. I enrolled in a two-year, introductory physics sequence
that used The Feynman Lectures in Physics as the textbook.
The Lectures were mesmerizing and inspirational. Feynman made physics seem so beautiful
and his love of the subject is shown through each page. Learning
to do the problem sets was another matter, and it was only years
later that I began to appreciate what a magician he was at
getting answers.
In my sophomore year, I became increasingly interested in
mathematics and declared a major in both mathematics and physics.
My math professors were particularly good, especially relative to
the physics instructor I had that year. If it were not for the
Feynman Lectures, I would have almost assuredly left physics. The
pull towards mathematics was partly social: as a lowly
undergraduate student, several math professors adopted me and I
was invited to several faculty parties.
The obvious compromise between mathematics and physics was to
become a theoretical physicist. My heroes were Newton, Maxwell,
Einstein, up to the contemporary
giants such as Feynman, Gell-Mann, Yang and Lee. My courses did not stress the
importance of the experimental contributions, and I was led to
believe that the "smartest" students became theorists while the
remainder were relegated to experimental grunts. Sadly, I had
forgotten Mr. Miner's first important lesson in physics.
Hoping to become a theoretical physicist, I applied to Berkeley,
Stanford, Stony Brook (Yang was there!) and Princeton. I chose to go to
Berkeley and entered in the fall of 1970. At that time, the number of
available jobs in physics was shrinking and prospects were especially
difficult for budding young theorists. I recall the faculty admonishing
us about the perils of theoretical physics: unless we were going to be
as good as Feynman, we would be better off in experimental physics. To
the best of my knowledge, this warning had no effect on either me or my
fellow students.
After I passed the qualifying exam, I was recruited by Eugene
Commins. I admired his breadth of knowledge and his teaching
ability but did not yet learn of his uncanny ability to bring out
the best in all of his students. He was ending a series of beta
decay experiments and was casting around for a new direction of
research. He was getting interested in astrophysics at the time
and asked me to think about proto-star formation of a closely
coupled binary pair. I had spent the summer between Rochester and
Berkeley at the National Radio Astronomy Observatory trying to
determine the deceleration of the universe with high red-shift
radio source galaxies and was drawn to astrophysics. However, in
the next two months, I avoided working on the theoretical problem
he gave me and instead played in the lab.
One of my "play-experiments" was motivated by my interest in
classical music. I noticed that one could hear out-of-tune notes
played in a very fast run by a violinist. A simple estimate
suggested that the frequency accuracy, 
times the duration of the
note,
did not satisfy the uncertainty
relationship
. In order to test the frequency
sensitivity of the ear, I connected an audio oscillator to a
linear gate so that a tone burst of varying duration could be
produced. I then asked my fellow graduate students to match the
frequency of an arbitrarily chosen tone by adjusting the knob of
another audio oscillator until the notes sounded the same.
Students with the best musical ears could identify the center
frequency of a tone burst that eventually sounded like a "click"
with an accuracy of 
.
By this time it was becoming obvious (even to me) that I would be
much happier as an experimentalist and I told my advisor. He
agreed and started me on a beta-decay experiment looking for
"second-class currents", but after a year of building, we
abandoned it to measure the Lamb shift in high-Z hydrogen-like
ions. In 1974, Claude and Marie Bouchiat published their proposal
to look for parity non-conserving effects in atomic transitions.
The unified theory of weak and electromagnetic interactions
suggested by Weinberg, Salam and
Glashow postulated a neutral
mediator of the weak force in addition to the known charged
forces. Such an interaction would manifest itself as a very
slight asymmetry in the absorption of left and right circularly
polarized light in a magnetic dipole transition. Gene was always
drawn to work that probed the most fundamental aspects of
physics, and we were excited by the prospect that a table-top
experiment could say something decisive about high energy
physics. The experiment needed a state-of-the-art laser and my
advisor knew nothing about lasers. I brashly told him not to
worry; I would build it and we would be up and running in no
time.
This work was tremendously exciting and the world was definitely
watching us. Steven Weinberg would call my advisor every few
months, hoping to hear news of a parity violating effect. Dave
Jackson, a high energy theorist, and I would sometimes meet at
the university swimming pool. During several of these encounters,
he squinted at me and tersely asked, "Got a number yet?" The
unspoken message was, "How dare you swim when there is important
work to be done!"
Midway into the experiment, I told my advisor that I had suffered
enough as a graduate student so he elevated me to post-doc
status. Two years later, we and three graduate students published
our first results. Unfortunately, we were scooped: a few months
earlier, a beautiful high energy experiment at the Stanford Linear
Collider had seen convincing evidence of neutral weak
interactions between electrons and quarks. Nevertheless, I was
offered a job as assistant professor at Berkeley in the spring of
1978.
I had spent all of my graduate and postdoctoral days at Berkeley
and the faculty was concerned about inbreeding. As a solution,
they hired me but also would permit me to take an immediate leave
of absence before starting my own group at Berkeley. I loved
Berkeley, but realized that I had a narrow view of science and
saw this as a wonderful opportunity to broaden myself.
A Random Walk in Science at Bell
Labs
I joined Bell
Laboratories in the fall of 1978. I was one of roughly two
dozen brash, young scientists that were hired within a two year
period. We felt like the "Chosen Ones", with no obligation to do
anything except the research we loved best. The joy and
excitement of doing science permeated the halls. The cramped labs
and office cubicles forced us to interact with each other and
follow each others' progress. The animated discussions were
common during and after seminars and at lunch and continued on
the tennis courts and at parties. The atmosphere was too electric
to abandon, and I never returned to Berkeley. To this day I feel
guilty about it, but I think that the faculty understood my
decision and have forgiven me.
Bell Labs management supplied us with funding, shielded us from
extraneous bureaucracy, and urged us not to be satisfied with
doing merely "good science." My department head, Peter
Eisenberger, told me to spend my first six months in the library
and talk to people before deciding what to do. A year later
during a performance review, he chided me not to be content with
anything less than "starting a new field". I responded that I
would be more than happy to do that, but needed a hint as to
what new field he had in mind.
I spent the first year at Bell writing a paper reviewing the
current status of x-ray microscopy and started an experiment on
energy transfer in ruby with Hyatt Gibbs and Sam McCall. I also
began planning the experiment on the optical spectroscopy of
positronium. Positronium, an atom made up of an electron and its
anti-particle, was considered the most basic of all atoms, and a
precise measurement of its energy levels was a long standing goal
ever since the atom was discovered in 1950. The problem was that
the atoms would annihilate into gamma rays after only
140x10-9 seconds, and it was impossible to produce
enough of them at any given time. When I started the experiment,
there were 12 published attempts to observe the optical
fluorescence of the atom. People only publish failures if they
have spent enough time and money so their funding agencies demand
something in return.
My management thought I was ruining my career by trying an
impossible experiment. After two years of no results, they
strongly suggested that I abandon my quest. But I was stubborn
and I had a secret weapon: his name is Allen Mills. Our strengths
complemented each other beautifully, but in the end, he helped me
solve the laser and metrology problems while I helped him with
his positrons. We finally managed to observe a signal working
with only ~4 atoms per laser pulse! Two years later and with 20
atoms per pulse, we refined our methods and obtained one of the
most accurate measurements of quantum electrodynamic corrections
to an atomic system.
In the fall of 1983, I became head of the Quantum Electronics
Research Department and moved to another branch of Bell Labs at
Holmdel, New Jersey. By then my research interests had broadened,
and I was using picosecond laser techniques to look at excitons
as a potential system for observing metal-insulator transitions
and Anderson localization. With this apparatus, I accidentally
discovered a counter-intuitive pulse-propagation effect. I was
also planning to enter surface science by constructing a novel
electron spectrometer based on threshold ionization of atoms that
could potentially increase the energy resolution by more than an
order of magnitude.
While designing the electron spectrometer, I began talking
informally with Art Ashkin, a colleague at Holmdel. Art had a
dream to trap atoms with light, but the management stopped the
work four years ago. An important experiment had demonstrated the
dipole force, but the experimenters had reached an impasse. Over
the next few months, I began to realize the way to hold onto
atoms with light was to first get them very cold. Laser cooling
was going to make possible all of Art Ashkin's dreams plus a lot
more. I promptly dropped most of my other experiments and with
Leo Holberg, my new post-doc, and my technician, Alex Cable,
began our laser cooling experiment. This brings me to the
beginning of our work in laser cooling and trapping of atoms and
the subject of my Nobel Lecture.
Stanford and the future
Life at Bell Labs, like Mary Poppins, was "practically perfect in
every way". However, in 1987, I decided to leave my cozy ivory
tower. Ted Hänsch had left Stanford to become co-director of
the Max
Planck Institute for Quantum Optics and I was recruited to
replace him. Within a few months, I also received offers from
Berkeley and Harvard, and I thought the offers were as good as
they were ever going to be. My management at Bell Labs was
successful in keeping me at Bell Labs for 9 years, but I wanted
to be like my mentor, Gene Commins, and the urge to spawn
scientific progeny was growing stronger.
Ted Geballe, a distinguished colleague of mine at Stanford who
also went from Berkeley to Bell to Stanford years earlier,
described our motives: "The best part of working at a university
is the students. They come in fresh, enthusiastic, open to ideas,
unscarred by the battles of life. They don't realize it, but
they're the recipients of the best our society can offer. If a
mind is ever free to be creative, that's the time. They come in
believing textbooks are authoritative but eventually they figure
out that textbooks and professors don't know everything, and then
they start to think on their own. Then, I begin learning from
them."
My students at Stanford have been extraordinary, and I have
learned much from them. Much of my most important work such as
fleshing out the details of polarization gradient cooling, the
demonstration of the atomic fountain clock, and the development
of atom interferometers and a new method of laser cooling based
on Raman pulses was done at
Stanford with my students as collaborators.
While still continuing in laser cooling and trapping of atoms, I
have recently ventured into polymer physics and biology. In 1986,
Ashkin showed that the first optical atom trap demonstrated at
Bell Labs also worked on tiny glass spheres embedded in water. A
year after I came to Stanford, I set about to manipulate
individual DNA molecules with the so-called "optical tweezers" by
attaching micron-sized polystyrene spheres to the ends of the
molecule. My idea was to use two optical tweezers introduced into
an optical microscope to grab the plastic handles glued to the
ends of the molecule. Steve Kron, an M.D./Ph.D. student in the
medical school, introduced me to molecular biology in the
evenings. By 1990, we could see an image of a single,
fluorescently labeled DNA molecule in real time as we stretched
it out in water. My students improved upon our first attempts
after they discovered our initial protocol demanded luck as a
major ingredient. Using our new ability to simultaneously
visualize and manipulate individual molecules of DNA, my group
began to answer polymer dynamics questions that have persisted
for decades. Even more thrilling, we discovered something new in
the last year: identical molecules in the same initial state will
choose several distinct pathways to a new equilibrium state. This
"molecular individualism" was never anticipated in previous
polymer dynamics theories or simulations.
I have been at Stanford for ten and a half years. The constant
demands of my department and university and the ever increasing
work needed to obtain funding have stolen much of my precious
thinking time, and I sometimes yearn for the halcyon days of Bell
Labs. Then, I think of the work my students and post-docs have
done with me at Stanford and how we have grown together during
this time.
From Les Prix Nobel. The Nobel Prizes 1997, Editor Tore Frängsmyr, [Nobel Foundation], Stockholm, 1998
This autobiography/biography was written
at the time of the award and later published in the book series Les
Prix Nobel/Nobel
Lectures. The information is sometimes updated with an addendum submitted
by the Laureate. To cite this document, always state the source as shown above.
Copyright © The Nobel Foundation 1997
) çıkarsa bu dosyanın güvenli olduğu ve güncellemenin LimeWire tarafından dağıtıldığı anlamını taşır ( Örnek: Alttaki resim) ve rahatlıkla indirme işlemini yapabilirsiniz.
