Nonlinear Physics Lab

Time-dependent conformations of flagella driven by dynein molecular motors,  with vectors showing the position and time-dependent velocity, and a graph of the body velocity. Note the desynchronization event.

Our work is supported by the National Science Foundation, Division of Materials Research under grant DMR-1104705. (disclaimer)

Our work on microbial swimmers is conducted jointly with Prof. Karl Johnson (Biology).

Velocity field induced in a fluid by a swimming cell (period 0.02 s)


Welcome to the Gollub Research Lab in the Department of Physics at Haverford College (also affiliated with the University of Pennsylvania).

Gollub's research is in the general area of Nonlinear Physics, which is concerned with the mesoscopic and macroscopic behavior of complex systems. Often these systems are described by nonlinear partial differential equations such as the Navier-Stokes equations of fluid motion.

His group has conducted experimental work on many aspects of nonlinear systems, addressing questions such as these: 

  • How do swimming microorganisms mix the surrounding fluid?
  • How do swimmers interact, and how do they affect the fluid around them?
  • How do sheared granular layers deform and fail?
  • When is the flow of a suspension reversible?
  • How can we use topological ideas to understand the onset of chaotic space-time motion in fluids? 
  • How do particles suspended in a fluid move?

Student Summer Projects: