The Parasol Effect
A hazy umbrella of sulfur particles is reflecting enough sunlight and heat back into space to offset global warming. You might think that's good news. Think again.
by David Berreby
Paleolithic Paint Job
Two French archeologists are trying to get closer--much closer--to an ancient act of creation.
Back to Nature
You can put a zoo-bred animal back into the wild. But that doesn't mean you're putting back anything like a wild animal.
Gravity Wave Sky
As cosmologists tune in the vibrations of space time, what will they hear?
Escape From 3-D
When you need to get a clearer view of a complex problem, there's nothing like stretching into 4, 5, 10, or even 26 dimensions. Just ask a mathematician.