The Center for Nonlinear Studies was created by then Laboratory Director Don Kerr in 1980 in response to both the emerging "nonlinear" science of solitons, dynamical systems and chaos and the important historical part played by Los Alamos scientists, most notably the Fermi-Pasta-Ulam numerical simulations of equipartition of energy in a nonlinear lattice system performed in 1955. Some of the later fundamental breakthroughs in the area of nonlinear science were achieved at Los Alamos National Laboratory. One of those accomplishments, achieved in the late 1970's by Mitchell Feigenbaum (Theoretical Division), built upon earlier work by Stan Ulam (T-Div.), John von Neumann, Mark Kac, Nick Metropolis (T-Div.), Paul Stein (T-Div.) and Stephen Smale. Feigenbaum made a key discovery connecting the qualitative and quantitative scaling behavior of a simple mathematical equation and predicted that such behavior would be universal for chaotic systems of a certain kind, specifically for period doubling. This discovery started a revolution in how complex systems are studied and understood. From these roots grew the Los Alamos Center for Nonlinear Studies.

The first Center Director was Alwyn Scott (1981-1985) whose research area was biological solitons. Five Laboratory technical staff members - Alan Bishop (T-11), David Campbell (T-8), Darryl Holm (T-7), Mac Hyman (T-7) and Basil Nichols (T-7) - were founding members of CNLS. A CNLS External Advisory Committee (EAC) was appointed in 1981 and the first Chairman was Mark Kac.

An active postdoctoral research program was central to the early CNLS research agenda. Erica Jen was the first CNLS postdoctoral fellow in 1981. Doyne Farmer joined later that same year. Other early postdoctoral fellows included Bob Ecke (1983), Peter Lomdahl (1984), David Brown (1985), and Ioannis Kevrekidis (1986).

Because much of the early activity at the Center for Nonlinear Studies was computational in nature, a field aptly entitled "experimental mathematics," CNLS was an early pioneer at the Laboratory in UNIX workstations and networking. In 1989, CNLS moved from its temporary quarters in T-Division to its new building where a computer machine room housed a suite of powerful computational platforms. A professional systems administrator was hired and CNLS became a leader in large scale computing with strong ties to emerging capabilities in the Advanced Computing Lab with its novel Thinking Machines CM series parallel computers. Ever since, CNLS has helped pioneer new concepts in computing, including the design and construction of the Avalon Beowulf UNIX cluster in 1998. CNLS provides expert computer support to its many postdoctoral researchers as well as to CNLS research affiliates, visitors and summer students. This capability is a Laboratory resource which supports scientific excellence in theoretical and computational modeling.

The organization of the Center evolved rapidly over its first 5 years. Alwyn Scott left after 4 years. Then, David Campbell was appointed Director in 1985. Under Dr. Campbell, CNLS was run with the help of a small group of internal advisors who formed the Executive Committee (EC). New members were added to the EC by first having them serve as part-time Deputy Director for one year. In 1987, the Deputy became a permanent position and Gary Doolen was hired into that role. Also about that time, a new Complex Systems Group was formed in T-Division with former CNLS postdoc Doyne Farmer as its first Group Leader.

Another early addition to the CNLS charter was a Distinguished Scholar position named after the brilliant Polish-American mathematician and LANL staff member, Stanislaw Ulam. The Ulam scholar position was designed to attract top level scientists, each spending a year at the CNLS interacting with students, postdocs and technical staff members. The first Ulam Scholar in 1985 was James Murray, an Oxford applied mathematician well known for his work inmathematical biology, in particular, morphogenesis.

During the 1980s and into the early 1990s, David Campbell synthesized the 4 paradigms of “nonlinear science”: 1) dynamical systems and chaos, 2) pattern formation, 3) coherent structures, and 4) cellular automata, neural networks and genetic algorithms. These topics provided a sharp focus for CNLS research while the activities at CNLS included a strong postdoctoral research program, a smaller student program with a larger summer contingent, many influential and important annual conferences and workshops (Note that until 2000, the CNLS Annual Conference was funded by the DOE/BES Applied Math Program at the level of about $50K), and numerous visitors from academic, industrial and government institutions.

Campbell’s tenure as Director saw significant increase in CNLS activity, size and influence including applications to important Laboratory programs such as synthetic metals and conducting polymers in MST, speech recognition in C (Computers), neural network efforts in X, porous-media simulations in EES using lattice-gas algorithms, etc. During the late 80s and early 90s, CNLS had a half-time Senior Scientist, Y.C. Lee, who participated in a wide spectrum of CNLS activities and had a large influence on significant research accomplishments.

Campbell left in 1993 during a period of change at the Laboratory which coincided with the end of the cold war. For several years, Gary Doolen, the CNLS Deputy Director, was the Acting Director with a series of temporary Deputy Directors including Bob Ecke, Erica Jen, and Ronnie Mainieri. CNLS maintained the status quo in that period until a new Director, Don Cohen of the Cal Tech Applied Math Department, was hired in 1996 by then T-Division Leader Dick Slansky. Don stayed only for one year but left an important long-term legacy through his hiring of a new Deputy Director, Charlie Doering, a former CNLS postdoc and currently a faculty member at University of Michigan.

In 1997, Hans Frauenfelder, who had recently retired after an outstanding academic career at University of Illinois and working in the Physics Division on aspects of biophysics, was hired as the fourth CNLS Director with Len Margolin and later Pieter Swart as Deputy Directors. Frauenfelder brought stability to CNLS with his outstanding scientific stature and helped to migrate CNLS toward biological physics. His concept of nonlinear science was oriented to a broader view of nonlinear science as the study of complex systems. The very interdisciplinary nature of CNLS continued under Frauenfelder.

In 2003, after 7 years as CNLS Director, Frauenfelder announced his desire to return to research. Robert Ecke of the Condensed Matter and Thermal Physics Group was appointed the fifth CNLS Director in February, 2005.

During the 1990’s, CNLS’ scientific activities continued at a high level with a continual eye on Laboratory applications. Among these were contributions to NMT Pu-Ti safety issues, Accelerator Transmutation of Waste program efforts, prediction and quantification of uncertainty, applications of soliton theory to optical-fiber transmission, the Avalon Beowulf cluster, etc. Recent postdocs have included three Feynman Fellows, an Oppenheimer Fellow, and Director’s-Funded Postdoctoral Research Associates. The 2001 CNLS Annual Conference on Soft Matter was the largest in CNLS history with over 300 participants. This was topped several years later by the ground breaking conference on Networks. Both have had significant impact in shaping LANL and CNLS activities.

In summary, CNLS has had an exceptional history of contributions in nonlinear science with excellent postdocs, a varied and stimulating series of conferences and workshops, and interactions with top external academic, industrial and national laboratory institutions. To look into where CNLS is headed, we next consider the present status of the CNLS and future challenges.