Science's most important (and controversial) number has its origins in a British experiment involving milk and tea.

As France fell to the German armies in May 1940, 400,000 Allied troops were trapped on the beaches of Dunkirk. Their annihilation seemed certain—a disaster that could have led to Britain’s surrender. But then, in a last-minute rescue, Royal Navy ships and a flotilla of tiny civilian boats evacuated hundreds of thousands of soldiers to safety across the Channel—the legendary “miracle of Dunkirk.”

Predictions underlie nearly every aspect of our lives, from sports, politics, and medical decisions to the morning commute. With the explosion of digital technology, the internet, and “big data,” the science of forecasting is flourishing. But why do some predictions succeed spectacularly while others fail abysmally? And how can we find meaningful patterns amidst chaos and uncertainty?

Churchill launches the largest military evacuation in military history. But there's a secret killer in the waters.

The flu vaccine changes from year to year and its efficacy varies. Here’s why.

How might science help avoid tragic deaths caused by landslides?

One unlucky day 13,000 years ago, a slight, malnourished teenager missed her footing and tumbled to the bottom of a 100-foot pit deep inside a cave in Mexico’s Yucatán. Rising seas flooded the cave and cut it off from the outside world—until a team of divers chanced upon her nearly complete skeleton in 2007.

Pilot André Borschberg reflects on his experience achieving what seemed impossible.

On March 9, 2015, Solar Impulse II took off from Abu Dhabi on one of the greatest aviation adventures of our time: the first solar-powered flight around the world. Together with a team of brilliant engineers, two visionary pilots—Bertrand Piccard and André Borschberg—designed and built Solar Impulse from scratch, even though top airplane manufacturers told them it would be “impossible to control.”

Pilot André Borschberg describes how it feels to fly in a plane entirely powered by the sun.

In honor of the New Year, we bring you a NOVA retrospective on ballistics.

Take a look back with us at the biggest science stories of 2017.

Crows can remember the face of their captors—even after generations.

Watch astonishing tests of avian aptitude: parrots that can plan for the future, jackdaws that can “read” human faces, and crows that can solve multi-step puzzles with tools like pebbles, sticks, and hooks. Could these just be clever tricks, based on instinct or triggered by subtle cues from their human handlers?

Here are three mind-blowing ideas for what may be inside a black hole.

As a kid, Janna Levin loved cosmology—now, she’s an award-winning author and host of “Black Hole Apocalypse”

Chung-Pei Ma is both a gifted violinist and one of the world’s foremost black hole hunters.

NOVA has teamed up with Cook's Illustrated to cook up a recipe for stars and black holes.