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?

MIT physicists have performed an idealized version of one of the most famous experiments in quantum physics. Their findings demonstrate, with atomic-level precision, the dual yet evasive nature of ...

When two black holes merge or two neutron stars collide, gravitational waves can be generated. They spread at the speed of light and cause tiny distortions in space-time. Albert Einstein predicted ...

Physicists at MIT recreated the double-slit experiment using individual photons and atoms held in laser light, uncovering the true limits of light’s wave–particle duality. Their results proved ...

Scientists at the X-ray free-electron laser SwissFEL have realized a long-pursued experimental goal in physics: to show how ...

Photons, for centuries both a puzzle and a tool, continue to help scientists illuminate nature at the smallest and largest scales. Photons, the fundamental particles of the electromagnetic field that ...