In this issue of Scientific American, "The Paradox of the Sun's Hot Corona." Like a boiling tea kettle on top of a cold stove, the sun's hot outer layers sit on a relatively cool surface. And astronomers are figuring out why. Two of them - Bhola Dwivedi and Kenneth J.H. Phillips - explain their findings. In "Solving the Mystery of Flight," Michael Dickinson explains how insects use a combination of aerodynamic effects to remain aloft. In "North to Mars!" Robert Zubrin explains why the Canadian Arctic is just about the perfect place to prepare for a trip to the red planet. Scientists could be unearthing the key to combating both baldness and excessive hair growth. Ricki Rusting has the story in "Hair: Why it Grows, Why it Stops." Also, meeting new exhaust emissions standards takes real effort. Steven Ashley writes that "A Low-Pollution Engine Solution" might offer the best hope of complying with the law.
©2001 Scientific American