To detect the so-called “quantum friction” forces that affect even objects in absolute void, scientists began to use rotation. A rotating nanoparticle trapped in a laser light in a vacuum is the active element of the most high-precision and highly sensitive sensor, capable of measuring centrifugal and other forces arising from rotation.
Note that the nanoparticle in question is currently able to rotate at a speed of more than 300 billion revolutions per minute. “This is the smallest and fastest human made rotor ever,” says Tongcang Li, a scientist at Purdue University.
To measure centrifugal and other forces, scientists illuminate the nanoparticle with pulses of light from a second laser, which follow with a uniform frequency, supported with high accuracy. The light of this laser is circularly polarized, the plane of oscillation of the electromagnetic wave of this light rotates with time. This change in the polarization of light serves as a kind of second more accurate sensor scale, which allows you to measure the change in the speed of rotation of the nanoparticles between two flashes of laser light.
When scientists took continuous measurements for 100 seconds, they got a torque value of 0.4 trillion quadrillion Newton meters. For reference, a torque of one Newton meter can make the hat raised at the tip of the index finger make a couple of turns. The results obtained allowed scientists to calculate that the sensor they created has 700 times greater sensitivity than any other sensor of rotation forces that was available to people until recently.
It is not yet clear whether the magnitude of the torque measured by scientists is the result of the work of “quantum friction.” After all, it may well be that all this is the result of the influence of yet another yet unknown factor, external electromagnetic fields, for example. But scientists hope that further experiments with the new sensor will allow them to find out.