Schematic of a single photon with zero angular momentum (green) splitting into two photons (red) with either zero or opposite angular momenta (sketched through the spatially varying color), which adds ...

When a magnetic material like nickel is zapped with an incredibly short laser pulse, it loses its magnetism almost instantly within femtoseconds, or a millionth of a billionth of a second. But physics ...

Surprising as it may sound, 107 years after the introduction of general relativity, the meanings of basic concepts are still being worked out. More than a century after Albert Einstein unveiled ...