Letters

Open Access Unnecessary for Physicists

It was interesting to read why a molecular biologist supports open access [APS News, Back Page, February 2007]. Interesting but unimportant. He has no idea of how a physicist thinks. When I have an interesting problem to solve, I like to work on it myself and see how far I can get. If I come up with an elegant solution, so much the better. I don’t want to first see what others have done and become biased and perhaps fall into the same pitfalls. The only time I access previous articles is when the referee forces me to.
 
I used to get paper copies of five journals. For lack of space, I have given up on all but two of them. I have open access to all of them, but I have not taken the time to look. Although it is good for archiving, open access doesn’t work for current literature except for people who have a lot of time on their hands. Bill Hooker notes that someone has to pay for open access but only says that half the costs comes from fees paid by the authors. He never says where the other half comes from.

Frank Chen
Los Angeles, CA

Simulations Teach Real Physics

I would like to commend Alan Chodos for the column “The Virtues of Virtual Experiments” in the February APS News. Among all the good reasons he gave for doing physics on a simulator I would like to emphasize the pedagogical. Events in a real laboratory happen too fast to observe the physics, so you learn lab techniques rather than the physics. I taught AP physics in a Blue Ribbon High School after I retired (part time, temp, since my PhD and years of practice did not qualify me as a Teacher) and the first thing I did was to put a leading physics software package on the server. I was later told that, since this package was available to any student, it received far more hits than any other package in the school system. The ability to assemble pieces and forces and watch the interaction unfold in slow motion animation, was irresistible.

Consider even the first experiment usually done in the lab: measuring g by dropping a weight. I teach g as being approximately 20 miles per hour per second, so in 2 seconds the dropped weight is going 40 miles per hour, too fast for the human eye to observe. On the other hand, watching the weight fall on a simulator, surrounded by virtual instruments showing “real” time and distances while watching in simulated time, with graphs growing, gives a much better gut feeling for acceleration.

Particle collisions and statistical mechanics are much better taught on a simulator. The details of the individual collisions can be seen whereas in the lab the actual collision happens so fast that we only observe the results. Mass ratios, sizes, spin, friction, drag, elasticity can all be changed, easily, so the effects can be seen right away. I admit that the crashing of the carts and having them shoot off the runway is missing. As Chodos points out, simulation teaches electric flow more effectively than the lab. The fascination of drawing a spark from the Van de Graaff cannot be overlooked, nor other dramatic demo effects, but does looking at a computer motherboard teach you any physics?

The present generation has been brought up on computer games and so they just see this as another game but one with realistic interactions. Slow compared to the games, but infinitely more acceptable than the slowness in the lab in which, paradoxically, the main event happens too fast to be seen.

Henderson Cole
Danbury, CT