Cell division

Reacting to worries that the electromagnetic waves broadcast by cellular phones could cause brain cancer, the city of San Francisco on June 22 passed the "Cell Phone Right-to-Know" ordinance by a 10 to 1 vote. The law requires stores to display the radiation emission levels of every cell phone offered, thus advertising to customers the option of a phone with lower and presumably safer levels.

But the cell phone industry says the ordinance will only confuse customers. The FCC already regulates cell phone radiation and doesn't allow phones to be sold in the United States that exceed its established safety threshold. Furthermore, the link between cell phones and cancer is suffering from an acute lack of evidence.

If you're one of the world's 4.6 billion cellular talkers, here's good news: A recent study of 7,000 British children found no increased risk for cancer among those born or raised near cell phone towers. According to the American Cancer Society, of about 30 studies that have searched for a phone-tumor link, most found absolutely no correlation. In the largest project, researchers spent $24 million surveying 13,000 cell phone users in 13 countries over the course of 10 years. When the results were published in May, they were inconclusive-neither confirming nor denying a brain cancer connection.

The uncomfortable problem in cases like this is that there are always a few studies reaching opposite conclusions. For instance, some research suggests that radio frequency radiation can indeed have a harmful effect on cells and DNA, and some Swedish studies claim to have found the ghostly tumor link. (Indian scientists even say cell phones cause honeybee colonies to decline when placed directly in the hive.)

The alleged danger remains too doubtful to justify holding my Motorola at arm's length and answering via speakerphone. I'll hold out for more research. A study begun in April-the most massive yet-aims to track the health and cell phone habits of a quarter of a million Europeans for the next 30 years. That's a long wait, but maybe it will settle the question for good.

Downsized proton

High-school chemistry refresher: Protons and neutrons form the nucleus of an atom and are surrounded by negatively charged electrons. Since at least the 1950s, the theory of quantum electrodynamics has successfully explained how protons and electrons interact. It's also given a precise measurement for the radius of the proton: 0.8768 femtometers, which is under one-quadrillionth of a meter.

But if a new particle accelerator experiment is correct-and dozens of scientists internationally believe that it is-protons may be 4 percent smaller than thought (a mere 0.84184 femtometers). In the context of quantum calculations, the 4 percent difference is "a very serious discrepancy," in the words of one physicist. The experiment may force a second look at the commonly accepted model of quantum physics-or could indicate the existence of a previously unknown particle type.