Quantum mechanics is both the most powerful theory physicists have ever devised and the most baffling. On the one hand, ...

Add Yahoo as a preferred source to see more of our stories on Google. The Greenberger–Horne–Zeilinger (GHZ) paradox describes how quantum theory cannot be described by local realistic descriptions. A ...

For over a century, quantum mechanics has challenged our established notions of physics. At its core are questions that unsettle our understanding of the universe: when does a quantum particle ...

That quantum mechanics is a successful theory is not in dispute. It makes astonishingly accurate predictions about the nature of the world at microscopic scales. What has been in dispute for nearly a ...

A radical idea that resolves many quantum paradoxes suggests there is no objective view of reality. How can the cosmos be stitched together from interlocking perspectives?

A team of quantum physicists has taken a concept that once lived purely in equations and turned it into hardware reality, creating a single particle of light that behaves as if it occupies 37 distinct ...

Quantum theory is a mind-bending idea, suggesting that, at the subatomic level, particles can exist in multiple states at the same time. Scientists often give the example of physicist Erwin ...

The original version of this story appeared in Quanta Magazine. Imagine standing on a railway platform watching a trolley go past. A girl on the trolley drops a bright red ball. To her, the ball falls ...

Classical and quantum mechanics don’t really get along as the science of the subatomic can get, well, weird. Take, for instance, quantum entanglement, which says that the state of one particle can be ...