Two mathematicians have proved that a straightforward question—how hard is it to untie a knot?—has a complicated answer.

High-frequency weekly indicators provide an up-to-date forecast and nowcast of the U.S. economy, signaling changes ahead of ...

How do we know the speed of light – and why does it have a speed limit at all? Leah Crane explores the history of one of the ...

Different species of spiders produce different silks that serve different purposes, from floating on air to cradling eggs. The triangle weaver spider, Hyptiotes cavatus, weaves and holds a three-sided ...

Astronomers are rethinking one of cosmology’s biggest mysteries: dark energy. New findings show that evolving dark energy models, tied to ultra-light axion particles, may better fit the universe’s ...

For the first time, an international research team led by the Shanghai Astronomical Observatory (SHAO) of the Chinese Academy ...

Learn how Hubble is measuring the expansion rate of the Universe in this new explainer from NASA's Goddard Space Flight ...

Water types include spring water, mineral water, distilled water, sparkling water, and purified water, among others. Some types may have more nutrients than others. Drinking enough water daily is ...

Discover how pigeons find a mate for life. Mes de Herencia Hispana con Cumbre Kids Únete a PBS Nature y Cumbre Kids durante el Mes de la Herencia Hispana. Environmental Stewardship of Nature via ...

Next week sees 25 new games and bundles heading to the PlayStation platform. Fast-paced 2D action-platformer where you step into the boots of a young knight on his very first adventure. Run, jump, ...