There was a secret inside the envelope in the hands of Stephan Schlamminger, one of the world’s leading experts in experimental tests of gravity. He appeared to be on the verge of opening the envelope ...

Schematic diagram of four experimental devices used by the co-author’s research team. Newton’s law of universal gravitation, which describes the attractive force between two masses separated by the ...

Researchers at the Kastler Brossel Laboratory in Paris have made the most precise measurement of one of the fundamental constants, called the fine-structure constant, providing physicists with a vital ...