This design illustrates the lines of force flowing through an electric field. The lines represent the trails, or traces, of very light particles moving through a complex field generated by twelve stationary, highly charged particles. The bright regions are areas of "high traffic" where their paths converge. The design is based on images created by Michael Danziger at the Center for Educational Computing Initiatives for the TEAL/Studio Physics Project at MIT. For more information, visit http://icampus.mit.edu/teal.

Cover design by Sandy Farrier, Publishing Services Bureau