Columbia Through the Decades
The graduate department was formally established in 1892, although the roots of graduate physics can be traced to the opening of the School of Mines in 1864. The first physics PhD recipient, Robert Millikan, received his degree in 1895 and went on to win the 1923 Nobel Prize in Physics. The central figure in the early years of the Department was Michael Pupin, who contributed substantially to new discoveries involving X-rays and to the continued understanding and applications of electromagnetism. He served as Department Chair for many years. Under his impressive leadership, the present Pupin Laboratory was completed in 1925 to serve as the home of the Physics Department. After his death in 1935, the building was named for him. The Department still resides here.
In May 1899, the American Physical Society was founded at Columbia. The Earnest Kempton Adams (EKA) Fund was established in 1904, enabling the department of Physics to invite distinguished scientists to Morningside. H.A. Lorentz was appointed EKA Lecturer in 1905-1906 and Max Planck in 1909. One of Lorentz’s most important works, The Theory of Electrons, was written during his tenure at Columbia.
In the early years of the twentieth century, Lorentz’s work had led to Einstein's theory of relativity, and Planck's black-body radiation formula led Einstein to the concept of the quantum, which culminated in the theory of quantum mechanics, developed by Bohr, Schroedinger, Heisenberg and many others in Europe over the two decades from 1910-1930. These ideas underlie our present understanding of nature at its most fundamental level, and represent great historical intellectual achievements. Most modern scientific and technological developments--nuclear energy, atomic physics, molecular beams, lasers, x-ray technology, semiconductors, superconductors, supercomputers-- were realized only because we could build on the foundations of relativity and quantum mechanics. The Columbia Physics Department played significant roles in several of these and related developments over ensuing decades.
I.I. Rabi, a Columbia graduate student in the 1920’s, was very interested in the new Quantum Mechanics being developed primarily in Europe. After completing his degree, he received a Barnard fellowship and spent 1927-1928 in European laboratories, learning about Quantum Mechanics. On his return to Columbia, he joined the faculty in 1929, and brought knowledge of Quantum Mechanics with him to the U.S. He spearheaded successful efforts to put Columbia, and the U.S., at the forefront of scientific research, winning the Nobel Prize in Physics in 1944. The study of quantum phenomena has been a primary focus of the Columbia Physics Department since the 1930's.
By 1931, Columbia had become a visible science presence with Harold Urey’s discovery of deuterium (Nobel Laureate in Chemistry, 1936) using a new spectrometer in Pupin Laboratory. That reputation continued as Rabi did his famous work with atomic beams and George Pegram investigated phenomena associated with the newly discovered neutron. In the fall of 1938, Italian fascism had created a hostile environment for Enrico Fermi, so he decided to leave his native country. His Nobel Prize award that year gave him the perfect opportunity to visit elsewhere. He wrote to George Pegram regarding this possibility, and received every encouragement to come to Columbia.
I.I. Rabi's contributions to the development of atomic and molecular physics and some of the basic discoveries in nuclear fission by Enrico Fermi and his collaborators ushered in a golden era of fundamental research. This period just prior to World War II was marked particularly by Rabi’s measurements of the spins and magnetic moments of atoms and nuclei, by the construction of the “Pupin cyclotron” by Dunning, and by the work of Fermi, Dunning and others on nuclear fission.
The war years saw great activity at Columbia and by Columbia faculty. Soon after Fermi arrived, he set about verifying the fission properties of the Uranium isotopes and pursuing what later became the Manhattan Project to develop the first nuclear weapon. Rabi, as wartime Director of Research of the Radiation laboratory located at MIT, worked on the development of radar.
After the end of the Second World War, Columbia Physics faculty focused their attention on fundamental physics questions, leading to many groundbreaking experiments, particularly those by Polykarp Kusch and Henry Foley on the magnetic moment of the electron and Willis Lamb's work on the fine structure of hydrogen. These experiments led to Lamb and Foley sharing the 1955 Nobel Prize in Physics. Theoretical research in the late 1940s was closely coupled with these atomic physics experiments, emphasizing how fundamental theory could produce precise calculations to match the precision experiments. By probing the magnetic moment of the electron (Kusch) and studying the fine structure of the hydrogen atom (Lamb), the results of these experiments were crucial to the development of quantum electrodynamics (QED). QED merged the laws of Quantum Mechanics with Maxwell's Theory of Electromagnetism, providing a detailed theory to describe the interactions of matter and light. Julian Schwinger, who received a Columbia B.A in 1936 and a Columbia Ph.D. in 1939, shared the 1965 Nobel prize in Physics for his fundamental work on QED.
Microwave techniques developed by Columbia faculty members during the war were later used to explore molecular spectra; the observation of large nuclear quadrupole moments stimulated the unified nuclear model of James Rainwater and Aage Bohr. Molecular spectroscopy also led Charles Townes and his collaborators to the development of the maser, the microwave precursor of the laser. These works were recognized by the Nobel Foundation.
High energy physics and properties of subatomic particles increasingly became a major postwar focus. In 1950, Columbia's cyclotron was commissioned at Nevis Laboratories in Westchester County about twenty miles north of the Morningside campus. The Nevis Laboratories are located on a 68 acre estate originally owned by James Hamilton, son of Alexander Hamilton. The cyclotron operated through 1978, by which time particle accelerators had grown to such a large size that they were located at national or international sites. Nevis Laboratories evolved to be a major source of the technology and innovation used in the particle detectors located at major accelerators, a trend that continues today, with leading edge electronics for the ATLAS detector at the Large Hadron Collider being developed at Nevis.
In the 1950's Tsung-Dao (T. D.) Lee, his collaborators, and their students made major strides in understanding the symmetries of subatomic particles, culminating in the prediction of parity violation in the weak interactions. The effect of maximal parity non-conservation was quickly observed in the landmark nuclear physics experiment conducted by C.S. Wu. With knowledge of Wu's measurement of maximal parity violation, parity violation was promptly found in pion-decay and muon-decay experiments by Leon Lederman and Richard Garwin at Nevis. T.D. Lee shared the 1957 Nobel Prize in Physics for his work on parity violation.
The desire to investigate matter on an increasingly finer scale led to experiments using beams of ever higher energies. Beginning in the 1950’s, the Nevis cyclotron and accelerators at Brookhaven National Laboratory were used in a number of experiments that continued beyond the decade. The structure of nuclei was delineated by observing X-ray transitions in muonic atoms; observations of pion and muon decay constituted further validation of maximal parity non-conservation; and in 1964, Leon Lederman, Mel Schwartz, and Jack Steinberger proved that the muon neutrino was distinct from the electron neutrino. This three shared the 1988 Nobel Prize in Physics "for the neutrino beam method and the demonstration of the doublet structure of the leptons through the discovery of the muon neutrino”.
During the ensuing two decades, experiments at FNAL with neutrino beams, led by Columbia experimenters, verified electroweak predictions of the Standard Model, and definitively established the quark and gluon constituency of nucleons assumed in QCD. Furthermore, these and other experiments demonstrated QCD as the best predictor of measurable strong interaction phenomena. Beginning in 1985, Columbia physicists led experiments using the accelerator complex at the German DESY laboratory, where predictions of the Standard Model were further verified while searching for specific effects beyond the Model. Properties of nucleon structure and QCD, the force holding quarks within the proton were investigated in many different ways and in phenomena that QCD did not easily predict. In the process, the proton was found to contain huge numbers of gluons carrying very tiny fractions of the proton momentum as expected in the developed QCD theory; where such gluons carry the strong interaction force.
Many studies of the second quark family’s charm quark were carried out in the period between 1985 and 1995 by Columbia physicists at the Cornell accelerator. These measured specific properties of charm, and properties of the binding of charmed quarks inside nucleons. Additional studies of important properties of the bottom quark were led by Columbia physicists using the Stanford SLC accelerator during the same period. This program also provided important information on the properties of the elementary bosons that carry the electroweak forces.
Substantial theoretical work on QCD continues to be carried out by Columbia theorists, with many difficulties to be overcome in making predictions from such a highly nonlinear theory. Since 1981, Columbia theoreticians have led in designing, constructing, and utilizing novel parallel processing computing systems to carry out these calculations. The details of many strong interaction phenomena, including the binding properties and masses of specific meson and baryon states, could begin to be predicted with accuracy.
By 1990, Columbia-led experiments were exploring implications of QCD in collisions of heavy nuclei at higher and higher energies. In collaboration with Brookhaven National Laboratory, the Relativistic Heavy Ion Collider (RHIC), constructed to accelerate and collide heavy nuclei, is advancing our understanding of nuclei and explores new forms of nuclear matter, including the quark-gluon plasma. This program continues today.
Columbia scientists will be playing an important role in major experiments at the soon-to-be completed LHC super-high energy collider in Switzerland. Among other exciting possibilities, these may at last reveal the origin of the masses of the familiar elementary particles of our Universe. Columbia physicists are also continuing to play important leadership roles using neutrinos to understand their intrinsic nature, including their masses and interactions with each other.
By the early 1970s, particle physicists began using even higher energy accelerator beams, and Columbia experimenters spread out to accelerators in Europe and the new Fermi National Accelerator Laboratory (FNAL) west of Chicago. By mid-decade, the Standard Model of elementary particles was becoming established, with electroweak interactions and quantum chromodynamics (QCD) describing the basic forces and constituents of matter. It ultimately incorporated three families of leptons (electron-like) and three families of quarks (proton-like) as the observed constituents, with two members in each family. The second quark family, with one already well-established (“strange”) member was then confirmed to have a second member: the “charm” quark.In 1977, Lederman led an effort at FNAL which discovered the first member (“bottom” quark) of the third quark family. (The remaining very massive “top quark” was confirmed in 1995 by experiments performed at Fermilab; collaborators from Columbia participated in this discovery.)
Astrophysics had its roots in early collaborations between astronomers and physicists at Columbia. In 1967 the Columbia Astrophysics Laboratory (CAL) was founded and, under the leadership of Columbia physicist Robert Novick, this fledgling organization quickly moved to the frontier of high energy astrophysics. By the early 1970's, CAL was, along with MIT, Harvard, and the NASA Goddard Space Flight Center, the architect of a series of three satellites that would make X-ray observations a central feature of our study of the Universe. Today the astrophysics lab boasts 23 faculty, 37 other PhD scientists and 40 graduate students from three departments.
In addition to studies of extraterrestrial X-rays, areas of research in the department have included measurements of the very highest energy cosmic rays; design, construction, and operation of innovative instruments to find the thus far undiscovered dark matter; measurement of the radiation from the Big Bang, detection and studies of neutron stars and black holes; and charting the star formation history of the Universe. Throughout the entire period, such experimental and observational efforts have always complemented forefront theoretical and phenomenological research.
Building upon the success of QED in describing the interactions of matter through the electromagnetic force, in the early 1970's, quantum chromodynamics (QCD) was proposed as the theoretical description of the strong nuclear force. In contrast to QED, calculations in QCD were substantially more complicated and the approximations inherent in these calculations made them less reliable. Columbia theorists Norman Christ and Alfred Mueller made important contributions to understanding these calculations.
In 1974, a workshop on heavy ion collisions was held in Bear Mountain, New York. T.D. Lee posed questions about new phenomena that might be observed by distributing high energy or high nuclear matter density over a relatively large volume. This could temporarily alter the normal vacuum state we experience and temporarily restore broken symmetries of the physical vacuum. This conference laid the foundations for what we now know as the study of heavy ion collisions and Brookhaven National Laboratory and the LHC at CERN.
Neutrino experiments by Columbia faculty date to the early days of the Nevis cyclotron and include the discovery of the muon neutrino at Brookhaven by Lederman, Schwartz and Steinberg. In the 1980's, neutrino physics at Columbia began a new era with experiments at FNAL with neutrino beams, led by Columbia experimenters including Frank Sciulli. These experiments verified electroweak predictions of the Standard Model, and definitively established the quark and gluon constituency of nucleons assumed in QCD. Furthermore, these and other experiments demonstrated QCD as the best predictor of measurable strong interaction phenomena.
Beginning in 1985, Columbia physicists led experiments using the HERA accelerator complex at the German DESY laboratory, which collided protons and electrons or positrons. These experiments further verified predictions of the Standard Model and also searched for exotic interactions beyond the Standard Model. Properties of nucleon structure and QCD, the force holding quarks within the proton were investigated in many different ways and in phenomena that QCD did not easily predict. In the process, the proton was found to contain huge numbers of gluons carrying very tiny fractions of the proton momentum as expected in the developed QCD theory; where such gluons carry the strong interaction force. Columbia theorists, particularly Alfred Mueller, were deeply involved in comparing the results from HERA with theoretical predictions from QCD.
While QCD was now a well established theory, there was no known procedure for analytic calculations of its properties at low energies. For example, the proton mass could not be predicted from first principles. Norman Christ and his collaborators began building a series of custom computers, with higher performance than commercially available, to numerically simulate the properties of QCD at low energies.
Although from the postwar period onwards, Columbia faculty had been involved in the study of complex material and electromagnetic systems, both from theoretical and experimental perspectives, by the early 1980's there was little research in the department focused on atomic physics or condensed matter physics. Experimental condensed matter physics had a rebirth in the department in the late 1980’s with the establishment of programs studying spin glasses and high temperature superconducting systems with muons and neutrons. The program grew with new people and efforts, both from joint programs with other departments and with new individuals who joined the department.
The department added a number of faculty in condensed matter physics in the 1990's, including Horst Stormer, who received the Nobel Prize soon after coming to Columbia for his discovery of the fractional quantum hall effect in 1982. Physics faculty were engaged in studies of ultrafast optoelectronics and spectroscopy and the study of new materials. Collaborations between faculty in Physics, Chemistry and the Engineering School put Columbia a leadership role in the burgeoning field of nanoscience.
In High Energy Physics, the remaining very massive “top quark” was confirmed in 1995 by experiments performed at Fermilab; collaborators from Columbia participated in this discovery. This left only a single expected standard model particle undiscovered, the Higgs boson, whose discovery would require almost two more decades of work.
To continue the important work on experimental astrophysics begun by the Columbia Astrophysics Laboratory, Steve Kahn and Charles Hailey came to Columbia in 1995. Merging methods from high energy particle physics and astronomy, they developed instruments to study X-ray and gamma-ray emissions from astrophysical objects.
The 1990s also saw considerable focus by Columbia faculty members on the development of the Relativistic Heavy Ion Collider (RHIC) at BNL and the detectors needed to record the results of these collisions.
During this decade, the Physics Department continued to focus on strengthening the research effort in condensed matter physics. New faculty in both theoretical and experimental condensed matter physics joined the department. Philip Kim, an experimental condensed matter physicist, joined the department in 2002, and studied physical properties of low dimensional materials, particularly graphene. Theoretical condensed matter physics was renewed with the appointment of Igor Aleiner, Boris Altshuler and Andrew Millis.
In Astrophysics, Professor Elena Aprile began an effort to detect dark matter with liquid xenon detectors. The XENON Project built a succession of ever larger detectors with increased sensitivity, to look for a signal of WIMP dark matter. The XENON100 detector (containing 100kg of liquid xenon) began operation in 2009.
With the hiring of Tanya Zelevinsky in 2008, research in Atomic, Molecular and Optical (AMO) Physics was reestablished in the department. After a many year lapse, the field where Rabi did much of his work was again represented at Columbia.
Although some of today’s questions and the tools used to answer them were inconceivable 50 years ago, one aspect of life in Pupin has not changed: Science at Columbia continues to be done by people who care deeply and passionately for the truth.
More detailed descriptions of current experimental and theoretical efforts can be found on the Research Overview page.