One of the most basic assumptions of fundamental physics is that the different properties of mass -- weight, inertia and gravitation -- always remain the same in relation to each other. Although all ...

Researchers at Hiroshima University have developed a realistic, highly sensitive method to detect the Unruh effect—a long-predicted phenomenon at the crossroads of relativity and quantum theory. Their ...

When the first-ever image of a black hole was released in April 2019, it marked a powerful confirmation of Albert Einstein’s theory of gravity, or general relativity. The theory not only describes the ...