The rate of photosynthesis has increased dramatically over the past century. Plants have been shielding us from some of the effects of climate change.

Four new elements--113, 115, 117, and 118--have been added to the periodic table. But the search for new elements hasn't always been so systematic. 

Carbon-14, or radiocarbon, was discovered 75 years ago by Martin Kamen and Sam Rubin at the UC-Berkely Radiation Lab