fundamental physics

Black holes may seem like interstellar enigmas, but they hold some key lessons on how to move through the universe.

A small cylinder called Le Grand K has defined the kilogram for more than a hundred years. But if a scratch ever rendered it lighter, the definition of the kilo literally shifted. Time for a change.

Harbor seals use sensors in their whiskers to help discern predator from prey. It's all about the way the water whirls, say scientists who are now training computers to be better trackers, too.