Physics on the Subway
Robert H. Romer

If you ride the buses serving the “Five-College” community here in western Massachusetts, on each bus you will find one or two “physics ads” in addition to the usual “Please don't eat on the bus” placards. In each one, a number of articulate cats and dogs get into a brief physics discussion, ending with “Let=s Try It!” and “What Do You Think? Visit Our Website:". Our initial questions include physics professor favorites such as "Which way does the tricycle go? " and "The helium balloon in a car" and questions of enduring interest to the public such as "Should I turn down the thermostat at night"? (That one seems obvious to us; to most ordinary people — i.e., nonphysicists — it is not obvious at all.) One of our placards, reproduced below, is an old physics puzzler, “Throwing the anchor overboard”. I am now a member of what may be a very select group - those who have done the experiment; no matter how solid the theory, I was not going to go public without the experimental test.

We want to give bus riders (and web surfers) the idea that thinking — even (or especially) about physics, with its bad reputation — can be fun. Physics deals not only with galaxies and quarks but also with everyday objects and phenomena. Don’t stop with our handful of questions — keep your eyes and minds open to the natural world around you.

Although this project is so far “Physics on the Bus” (and our local buses at that), we call it “Physics on the Subway (POTS)” to indicate our higher ambitions (for which we will need money beyond that provided so far by Amherst College and by our own pockets). POTS is a small part of a dream that John King and I call “Physics Everywhere” starting in the cradle with an “Age-Zero Physics Kit” for every newborn child. (See King’s Oersted Medal talk “Observation, experiment, and the future of physics”, Am. J. Phys. 69 (1), 11-25 (2001) for a full description.) The idea of putting placards on buses and subways is one that we were pleased to borrow from physicists in the U.K. who have done something similar on the London Underground. (Brenda Keogh, Stuart Naylor, and Catherine Wilson, “Concept Cartoons: A new perspective on physics education”, Phys. Educ. 33 (4), 219-224 (1998).) Our drawings are by our talented artist and collaborator, Bruce Aller.

cartoon 1
cartoon 2
cartoon 3
cartoon 4


The website has received a great many emails (and I feel guilty about not having answered all of them yet). Some are just nice: "It's wonderful to have found something entertaining AND intelligent on the internet for a change. I look forward to more Qs&As. Keep up the good work! " Some argue with our answers: "You=re wrong! The trike goes backward. I haven’t tried it, but I don’t need to. Too bad you made a mistake. Interesting, anyhow. ” Many have suggested more questions for us or simply asked us to respond to theirs: “This is a little morbid, I admit, but it’s something I have wondered about for years. If you are in an elevator that is falling, will jumping up and down reduce your chance of being killed when it hits — assuming, of course, that you are in mid-air when the elevator hits bottom. Thanks!”

We would welcome your comments, suggestions for further questions, and especially for thoughts about other transit systems that might be as cooperative in this project as UMass Transit has been.

Robert H. Romer,
Department of Physics, Amherst College, Amherst, Massachusetts 01002 ;