An engineer who once worked with NASA says he has built a machine that can push against gravity without burning a drop of fuel, a claim that, if true, would upend how rockets, satellites, and even ...

For more than a century, gravity has been the stubborn outlier in physics, perfectly described on cosmic scales yet refusing to mesh with the quantum rules that govern everything else. A growing camp ...

A new argument explores how the growth of disorder could cause massive objects to move toward one another. Physicists are both interested and skeptical. Isaac Newton was never entirely happy with his ...