Explainers

When your mind is wandering, your brain’s “default mode” network is active. Its discovery 20 years ago inspired a raft of research into networks of brain regions and how they interact with each other.

Quadratic reciprocity lurks around many corners in mathematics. By proving it, number theorists reimagined their whole field.

Mathematical logic and the code of computer programs are, in an exact way, mirror images of each other.

Exposure to a virus isn’t an all-or-nothing proposition. The concept of “infectious dose” suggests ways to keep ourselves safer from harm.

Scientists have struggled to accurately forecast the strength of the sun’s 11-year cycle — even after centuries of solar observations.

Mathematical proofs based on a technique called diagonalization can be relentlessly contrarian, but they help reveal the limits of algorithms.

For over a century, biologists have had to contend with a complicated picture of genetics, which they’ve only recently begun to understand.

Transcendental numbers include famous examples like e and π, but it took mathematicians centuries to understand them.

To buffer the brain against menaces in the blood, a dynamic, multi-tiered system of protection is built into the brain’s blood vessels.