Albert Einstein shattered previous ideas about time, but left many pivotal questions unanswered: Does time have a beginning? An end? Why does it move in only one direction? Is it real, or something our minds impose on reality?

Dark energy is cosmology’s biggest mystery—an anti-gravitational force that confounds the conventional laws of physics. It makes up more than two-thirds of the cosmos, but science is still grappling to explain what dark energy actually is.

Black holes are gravitational behemoths that dramatically twist space and time. Recently, they’ve also pointed researchers to a remarkable proposal—that everything we see may be akin to a hologram.

You exist. You shouldn’t. Stars and galaxies and planets exist. They shouldn’t. The nascent universe contained equal parts matter and antimatter that should have instantly obliterated each other, turning the …

Chemist Raychelle Burks is on the front lines of forensic science, developing ways to detect drugs and explosives. Episode filmed live at the 2016 World Science Festival in New York …

“Because it’s there” was George Mallory’s famous explanation for why he risked (and lost) his life trying to become the first person to summit Everest. We don’t all want to …