Video: Why isn't weed killer working anymore?

Farmers used to worry about weeds. Then, herbicides solved that problem. At least for a while. In 1997, there were 432 new patents for herbicides; by 2009, there were only 65.

Video: How quinine caused World War I

If we look at how the bark of the cinchona tree is used to treat malaria, we can see the cutting-edge chemistry of quinine binding an enzyme essential for the malaria parasite's survival.

Video: What is an electron?

When it comes to electrons—one of the fundamental building blocks of all matter—there are lots of unanswered questions. How big are they? What are they made out of? What … are they?

page 1 from 4