Cosmologist Sean Carroll tackles a deceptively simple question: Why does time exist at all? The potential answers point to a surprising view of the nature of the universe, and our place in it.
Psychologist Laura Carstensen says that as people get older, they usually become less stressed and more content.
Dan Gilbert shares research on what he calls the "end of history illusion," where we think the person we are right now is the person we'll be for the rest of time. Hint: that's not the case.
The American chestnut is poised to return — as a bionic, blight-resistant tree. Scientists hope to plant about 10,000 transgenic plantlets to pollinate trees in the "wild."
Planned Parenthood has an app that offers discreet help for Californians seeking to get tested for chlamydia or gonorrhea.
To stop elephant slaughter in Africa, zoologist Sam Wasser spent years extracting DNA from elephant dung and tissue. Much of the world's poached ivory, he discovered, comes from just three places.