In what many call a “golden age of cosmology”, astronomers can now observe the universe with unprecedented precision, resulting in spectacular progress in the search for the origin of the universe. Yet, for all the impressive progress, fundamental questions remain. What is the mysterious “dark energy” driving space to rapidly expand?

How much brain do you need to be smart? Bees and ants perform marvels as colonies, though each insect has barely any brain. And plants—with no brain at all—exhibit behaviors …

We spend a third of our lives asleep. Every organism on Earth—from rats to dolphins to fruit flies to microorganisms—relies on sleep for its survival, yet science is still wrestling with a fundamental question: Why does sleep exist?

Cosmology is the one field in which researchers can—literally—witness the past. The cosmic background radiation, ancient light streaming toward us since the Big Bang, provides a pristine window onto the birth and evolution of the universe.

Einstein dreamed of a unified theory of nature’s laws. String theory has long promised to deliver it: a mathematically elegant description that some have called a “theory of everything.” Join …

What is time? Isaac Newton described it as absolute, but Einstein proved that time is relative, and, shockingly, that time and space are intricately interwoven. Now recent work in string theory and quantum gravity suggests that space and time may not be fundamental. If this is true, what new picture of reality will emerge?