More than a century after Einstein first devised the equations that describe gravity, physicists are still finding new ways of interpreting them. Luca Comisso, an associate research scientist in Columbia University’s departments of Astronomy and Physics and the Columbia Astrophysics Laboratory, and Felipe A. Asenjo of Universidad Adolfo Ibáñez in Chile, recently found a new way of looking at Einstein’s equations that reveals a striking analogy with “magnetic reconnection” in plasmas, which occurs when magnetic field lines break and reconnect, powering explosive phenomena such as solar flares.

Hula hooping may be literal child’s play, but as it turns out, the physics behind the gym-class staple is so complicated that scientists have spent decades trying to understand how the hula hoop defies gravity.

In nonreciprocal active matter, agents act differently on each other, seemingly in violation of Newton’s third law. This principle can result in various active matter traits, such as self-propulsion, molecular regulation and collective motion.