A groundbreaking experiment demonstrates yet again that light exists both as a wave and a particle in the quantum world—but we can’t see both at the same time.

Researchers at MIT have conducted what they are calling the most "idealized" double-slit experiment yet, finding further evidence that Einstein's take on the phenomenon is likely incorrect. The double-slit experiment and its variations is one of the weirdest results humans found as we began to study the world scientifically.

Simply put, scientists have conducted a super-advanced version of the most famous experiment in quantum physics. More than two centuries ago, the "double slit" experiment powerfully demonstrated that photons of light can behave either as particles or waves.