In the late 1970s, legendary physicist John Wheeler proposed a radical question: Exactly when does the universe notice that we're paying attention to a quantum experiment? And does it really matter?

Add Yahoo as a preferred source to see more of our stories on Google. In 1920, Danish physicist Niels Bohr proposed that although light (photons) has a dual nature, behaving as both particle and wave, ...

Physicists confirm that light has two identities that are impossible to see at once. (Nanowerk News) MIT physicists have performed an idealized version of one of the most famous experiments in quantum ...

It's time for the latest update in confirming things we already knew—and, as always, it's being far more interesting than you might expect. Simply put, scientists have conducted a super-advanced ...

Quantum mechanics: it’s the realm of science where nothing is normal, and everything seems to undermine the fundaments of our common understanding of reality. Nonetheless, we simple humans tick on.

A real mind-melter: Quantum mechanics is strange, but even for a field of science that regularly defies our conventional understanding of reality, the latest discovery is particularly baffling.

The original version of this story appeared in Quanta Magazine. There are precision measurements, and then there’s the Laser Interferometer Gravitational-Wave Observatory. In each of LIGO’s twin ...