Rotating molecules appear blurred compared to non-rotating ones. Precession is a change in the orientation of the rotational axis of a rotating body. The Earth is rotating or spinning around its axis. Axial compressors consist of rotating and stationary components. Shielding material can be stationary around a rotating interior. Scanners are available that pull a flat sheet over the scanning element between rotating rollers. The framework is mounted on rails attached to a rotating platform. Angular accelerometers measure how the vehicle is rotating in space. Electronic controls may be operated by buttons, sliders, magnets, rotating heads, or rotating control rings. Vibration in rotating machines is monitored by accelerometers. It projected images from rotating glass disks. The primary one is fully automated and capable of rotating and emitting light. Stroboscopic effect may lead to unsafe situations in workplaces with fast moving or rotating machinery. These are often more popular than mechanical (rotating) hard drives. He imagined an observer performing experiments on a rotating turntable.