(CordisEuropa) Quantum mechanics and the theory of gravity are two well-established theories used to describe a large part of the physical world. However, both theories rest on mutually exclusive principles, which begs the question, ‘does gravity require a quantum description?’
“This is an experimental question, one that cannot currently be answered by experimental evidence,” says Markus Aspelmeyer, a quantum physicist at the University of Vienna.
To help answer this question, Aspelmeyer is leading the EU-funded QLev4G project. The European Research Council supported project aims to introduce a new experimental approach based on quantum controlling levitated solid-state particles. In doing so, researchers hope to lay the groundwork for conducting a new generation of experiments that will answer the gravity-quantum question.
According to Aspelmeyer, the project has made significant progress on both the quantum and gravity fronts. “On the gravity side, we managed to measure the gravitational field of the thus far smallest source mass in an experiment: a tiny gold sphere of only 1 mm radius and 90 mg mass,” he notes. “Whereas typical gravity experiments use masses that are at least 10 000 times larger!”

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