Between the usual advertisements and exhortations, riders on the University of Massachusetts transit system can now find placards inviting them to puzzle over physics. “We would like to give people the idea that physics can be fun, that physics can be interesting, that physics deals not just with quarks and galaxies, but with everyday objects like tricycles and rowboats and thermostats,” explains Amherst College’s Robert Romer, who is spearheading the puzzler project with help from John King of MIT.

One set of placards, for example, invites riders to consider what will happen when an anchor is tossed over the side of the S. S. Archimedes. A dog and a cat debate the issue: Will the water level rise because the anchor displaces water, or will it fall because of the reduced weight of the boat? The anchor problem is one of six that are being posted in UMass buses. The problems, their solutions, and, in many cases, guidance for simple experiments to confirm the solutions may be viewed on the Internet at

Romer and King’s project was inspired by a similar effort, Science on the Underground, initiated in London five years ago. The Massachusetts incarnation has cost about $13 000 to date, with most of the expense covering the drawing and printing of the placards. Amherst College has picked up a generous portion of the initial cost and hosts the Web site, and UMass transit has donated space on the buses. Romer and King hope to expand their program, most likely to bus systems in other university towns, but will need additional funds to do so.

The placards were drawn by Bruce Aller of Upton, Massachusetts. Romer admits that both he and Aller are cat people. “Some of my friends say, ‘The cat’s always right, that’s the clue.’ They have a point, but we promise to have the dog get the physics right in some of our future drawings.”