Does Nature Break the Second Law of Thermodynamics?

In seeming defiance of the second law of thermodynamics, nature is filled with examples of order emerging from chaos. A new theoretical framework resolves the apparent paradox

The Incredible Shrinking Scanner: MRI-like Machine Becomes Portable

A portable version of a room-size nuclear magnetic resonance machine can probe the chemistry and structure of objects ranging from mummies to tires

Jacking into the Brain--Is the Brain the Ultimate Computer Interface?

How far can science advance brain-machine interface technology? Will we one day pipe the latest blog entry or NASCAR highlights directly into the human brain as if the organ were an outsize flash drive?...

Smart DNA: Programming the Molecule of Life for Work and Play

Logic gates made of DNA could one day operate in your bloodstream, collectively making medical decisions and taking action. For now, they play a mean game of in vitro tic-tac-toe

Geoengineering: How to Cool Earth--At a Price

Global warming has become such an overriding emergency that some climate experts are willing to consider schemes for partly shielding the planet from the sun's rays. But no such scheme is a magic bullet...

Special Report: HIV--25 Years Later

The big challenges in the fight against HIV/AIDS

25 Years Later: The AIDS Vaccine Search Goes On

Repeated failures in the quest for an AIDS vaccine have sent investigators back to the drawing board

HIV 25 Years Later: The Big Challenges