首台量子祖父钟或可探究引力起源

RESEARCHERS have designed a quantum version of a pendulum clock using a single atom, tiny mirrors and light. Building it could help our understanding of what makes any clock accurate in the quantum realm and explore ideas at the edge of physics. At the most rudimentary level, time can be measured with something simple, like sand trickling through an hourglass. But timekeeping became a lot more accurate once mechanical clocks, like the grandfather or pendulum clock, were invented in the 17th century. Matteo Brunelli at the College of France and his colleagues have now shown that such clocks have a quantum equivalent. …