This new propulsion system could rewrite the rules of spaceflight—not to mention completely defy conventional physics.

All the fundamental forces are thought to be carried by a particle, but a new mathematical model suggests gravity may be a striking exception. Building on a decades-old idea, researchers have ...

It is constrained by the universal laws of physics. Each tree has to support its mass against the downwards force of Earth's gravity. At the same time, the trees rely on the strength of the ...