How to build a particle collider the size of the solar system. To observe the quantum nature of gravity and of spacetime itself, we need a particle collider the size of the solar system. Or we could ...

The ball rolls across the floor because it was kicked, just as Earth orbits the sun because it is tugged by gravity. The connection between cause and effect is fundamental to how we understand the ...

Does quantum mechanics allow the future to retroactively influence the past or not? Does quantum mechanics allow the future to retroactively influence the past, as in the infamous delayed choice ...

A number of experiments have been proposed to generate and witness gravitational entanglement, but Aziz and Howl’s work suggests that the presence of gravitational entanglement is not a ‘smoking gun’ ...