Sunday Lectures is a weekly roundup of the internet’s most interesting educational videos. Get smarter without getting out of bed.

What The Heck is a Multiverse?

The word “universe,” by definition, includes all matter and space taken as a whole. So how is it possible that multiple universes exist?

Gay Rights in Latin America

Gay marriage is now legal in Argentina, Brazil, and Uruguay — a surprising turn of events, considering their staunchly Catholic pasts. What led to the advance of gay rights in these countries might be key to neighboring nations hoping to follow suit.

Proof That Tetris Makes You Smarter

Changes in behavior, environment, and, apparently, video game play can lead the brain to rewire itself in a process called neuroplasticity. Neuroscientist Richard Haier illustrates by discussing a study on Tetris-related brain changes.

How To Make Good Decisions

The secret to optimizing decision making is being smart about weighing risks, says Gerd Gigerenzer, director of the Center for Adaptive Behavior and Cognition at the Max Planck Institute for Human Development. And part of being smart is not allowing manipulative politicians, physicians, and financial advisors to do the risk-weighing for you.

The Dark Universe

We don’t know much about what makes up dark matter and dark energy — but we do know what it’s not. The dark universe is thought to be the 73 percent of the cosmos that we can’t see or measure. Here, Nobel Prize-winning astrophysicist Adam Riess explores the limits of our understanding.