Here's how some of the world's greenest communities are shrinking their carbon footprint, and what cities and towns everywhere can learn from them. By Patrick Di Justo
Our environmentally perfect future is years away, but architects already have designs prepared for buildings that generate their own power -- and clean their surroundings -- using the sun, wind, and sea. By Suzanne LeBarre
Our staff photog installs a home system that uses shower runoff to flush the toilet. By John B. Carnett
Thousands of Americans are traveling abroad for controversial stem-cell treatments not approved by the FDA. Is it a scam or cutting-edge health care? by Elizabeth Svoboda
The incredible innovations, like drone swarms and perpetual flight, bringing aviation into the world of tomorrow. Plus: today's greatest sci-fi writers predict the future, the science behind the summer's biggest blockbusters, a Doctor Who-themed DIY 'bot, the organs you can do without, and much more.