News
- Earth
Hazy changes on high
A big boost in coal burning, especially in China, is adding aerosols to the stratosphere.
- Tech
Isotope crisis threatens medical care
Global production of the feedstock for the leading medical-imaging isotope is low and erratic, putting health care in jeopardy.
- Physics
Casper the Quantum Ghost
Researchers find that a strange kind of imaging relies on quantum mechanics.
- Archaeology
Fire engineers of the Stone Age
New evidence indicates that people used fires to heat stones in preparation for making cutting instruments at least 72,000 years ago in southern Africa.
