In a frictionless environment, such as space without gravity or air resistance, a pencil spun initially would continue to spin indefinitely due to the conservation of angular momentum, as no external torque acts on it. The centripetal forces acting on the pencil's structure do not do work, allowing it to maintain its motion without energy loss. While the pencil would theoretically spin forever, it may lose energy over time through gravitational waves if considering relativistic effects, though this loss is minimal. The discussion clarifies that perpetual motion machines are prohibited, but uniform circular motion in a vacuum does not violate any laws of physics. Ultimately, the pencil's spinning motion exemplifies Newton's first law, where an object in motion stays in motion unless acted upon by an external force.