The subtlest experiment in quantum mechanics is also one of the simplest: send a stream of particles through two openings in a barrier, and you’ll produce an interference pattern because the particles ...

Scientists test Einstein’s quantum challenge with one atom, directly measuring when photon paths erase interference stripes.

Complementarity A new twist on the double-slit experiment. (Courtesy: Shutterstock/Andrey VP) One of the most counterintuitive concepts in physics – the idea that quantum objects are complementary, ...

Light is well known to exhibit both wave-like and particle-like properties, as imaged here in this 2015 photograph. What's less well appreciated is that matter particles also exhibit those wave-like ...