A Short History of the Missing Universe
Astronomers have known where the universe’s missing matter has been hiding for the past 20 years. So why did it take so long to find it?
A New Test for the Leading Big Bang Theory
Cosmologists have predicted the existence of an oscillating signal that could distinguish between cosmic inflation and alternative theories of the universe’s birth.
How Insulin Helped Create Ant Societies
Evolution may have coopted an ancient metabolic mechanism to set social insects on the path toward one of the most puzzling behaviors found in nature.
Dark Energy May Be Incompatible With String Theory
A controversial new paper argues that universes with dark energy profiles like ours do not exist in the “landscape” of universes allowed by string theory
A Short Guide to Hard Problems
What’s easy for a computer to do, and what’s almost impossible? Those questions form the core of computational complexity. We present a map of the landscape.
Swarming Bacteria Create an ‘Impossible’ Superfluid
Researchers explore a loophole that extracts useful energy from a fluid’s seemingly random motion. The secret? Sugar and asymmetry.
Closed Loophole Confirms the Unreality of the Quantum World
After researchers found a loophole in a famous experiment designed to prove that quantum objects don’t have intrinsic properties, three experimental groups quickly sewed the loophole shut. The episode closes the door on many “hidden variable” theories.
The Hunt for Earth’s Deep Hidden Oceans
Water-bearing minerals reveal that Earth’s mantle could hold more water than all its oceans. Researchers now ask: Where did it all come from?
To Make Sense of the Present, Brains May Predict the Future
A controversial theory suggests that perception, motor control, memory and other brain functions all depend on comparisons between ongoing actual experiences and the brain’s modeled expectations.