Scientific American Magazine

Excess weight can harm health in ways that may come as a surprise

Changes in agriculture, policy and personal behaviors can reduce the energy a nation uses to feed itself and the greenhouse gases it emits

One of the most beautiful phenomena in meteorology has a surprisingly subtle explanation. Its study also helps to predict the role that clouds will play in climate change

Animals' magnetic sense is real. Scientists are zeroing in on how it works

Tipping the scales at less than about a million suns in mass, middleweight black holes may hold clues to how their much larger siblings, and galaxies, first formed

In cities across the U.S., data-rich computer technology is telling cops where crimes are about to happen. Crime is down, and the technology is spreading. But does it really work?

Researchers have uncovered an ancient mechanism that retards aging. Drugs that tweaked it could well postpone cancer, diabetes and other diseases of old age

When Ralph M. Steinman developed pancreatic cancer, he put his own theories about cancer and the immune system to the test. They kept him alive longer than expected—but three days short of learning he had won the Nobel Prize

Biologist Jayne Belnap warns of the consequences for the American West if we don't preserve a home for the minute organisms that live in desert topsoil