A Brief History of the Division of Physics, Mathematics and Astronomy at Caltech
When Robert Millikan accepted an offer in 1921 to become Caltech's first chairman of the Executive Council (a title he preferred over "president") and director of the Norman Bridge Laboratory of Physics, his appointment included an understanding that the limited resources of the fledgling California Institute of Technology – newly transformed from the Throop College of Technology – would be heavily invested in physics. To George Ellery Hale, the astronomer and visionary who brought Caltech into existence, and to Arthur Amos Noyes, the chemist and academician who developed Caltech's curriculum and insisted on the primacy of fundamental research, Millikan's stipulation paid both immediate and long-term dividends. Millikan's eminence in science and his national stature proved critical for fulfilling Caltech's goal to become a world-leading research institution out of the gate, and his receipt in 1923 of the Nobel Prize in Physics, for his studies of the photoelectric effect and of the elementary charge of electricity, helped thrust Caltech to global acclaim.
Accordingly, for the first several years of the Institute's existence, the physics program was the most prominent on campus, and it was decidedly skewed toward experimental work, according to Millikan's view that physics was essentially an experimental discipline, requiring exactly and only one theorist on the faculty. But by 1926, as Caltech was growing and as leading researchers from across the world were attracted to Pasadena and to the Institute's accumulating achievements across engineering, mathematics, and chemistry, the modern divisional structure that we know today began to take shape. That year marked the creation of the Division of Physics, Mathematics, and Electrical Engineering, based, in part, on professor Royal Sorensen's vision that the study of electrical engineering, no matter how "applied" in scope, must always begin with the fundamentals of mathematics and physics.
In the years after World War II, which vastly expanded the scope and complexity of Caltech research and ushered in a new funding structure based primarily on federal grants, the Institute, then under the leadership of Lee DuBridge, underwent its second major divisional transformation. In recognition of the rapid modernization and diversification of engineering and all its subfields, the Department of Electrical Engineering moved to the Division of Engineering and Applied Science, and in its place, a new astronomy program at Caltech was born, thereby creating the Division of Physics, Mathematics and Astronomy (PMA), as it has been known ever since.
Of course, with Hale as the leading Institute founder, and with the proximity of the Mt. Wilson Observatory as the primary motivating factor to create Caltech out of the Throop Institute, the study of astronomy was part of the Institute since its inception. But the completion of Palomar Observatory in 1948 as a joint venture with the Carnegie Institution compelled Caltech leadership to launch its own astronomy program. With the 200-inch telescope at Palomar – which would remain the world's most powerful optical telescope over the next four decades – Caltech embraced the singular opportunity to build on the historic contributions that nuclear physicists at Kellogg Laboratory had made to the study of stellar interiors with new capabilities in observational astronomy and to advance the field of astrophysics.
From its advent more than 75 years ago, Caltech's Division of Physics, Mathematics, and Astronomy has continued in Caltech's founding goal to be a world-leading center in basic science, technology development, and societal impact. From combinatorics to quantum information, and from quarks to quasars, the faculty, students, and alumni of the PMA division have brought clarity to the most confounding problems in mathematics, and they have illuminated our understanding of the world from its smallest to its largest scales. And despite the exponential growth that has defined academic research over the past century, the Division – like Caltech as a whole – has been steadfast in its insistence to remain small, based on the well-founded philosophy that a tight-knit and mutually supportive scientific community is one that will encourage chance encounters and the merging of distinct areas of expertise to forge new approaches to longstanding challenges, all in the name of pathbreaking discovery.
