Light mica plates with a mirror surface were blackened on one side and fixed on the axis of rotation as shown in the figure. This system was then placed in a glass vessel, from which the air was partially pumped out. If this vessel is now placed in a brightly lit room, the plates will start to rotate clockwise, and the faster the more light there is in the room. Having equipped this device with a measuring scale, you can use it as a radiometer - a device for measuring the intensity of light radiation. Explain how this device works.