To detect the quantum friction of empty space, scientists are going for a spin.
A twirling nanoparticle, suspended in a laser beam inside of a vacuum, can measure tiny twisting forces, making it the most sensitive detector of torque yet created. Researchers say the device could one day detect an elusive quantum effect called vacuum friction.
The suspended nanoparticle can spin more than 300 billion times a minute. “This is the fastest human-made rotor in the world,” says physicist Tongcang Li of Purdue University in West Lafayette, Ind.