Physicists detect spin momentum of light. They used an extremely sensitive nano-cantilever, capable of femtoNewton resolution—measuring a force smaller than the force gravity exerts on a single bacterium—immersed in an evanescent optical field directly above a total-internal-reflecting glass surface

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Physicists detect spin momentum of light. They used an extremely sensitive nano-cantilever, capable of femtoNewton resolution—measuring a force smaller than the force gravity exerts on a single bacterium—immersed in an evanescent optical field directly above a total-internal-reflecting glass surface