We say the sun moves from rising to setting even though actually the earth rotates and orbits around the sun. The orbits are for tracing and describe the movement of the sun and the earth and their relationship. Anyone who is looking for a physical track of the orbit is regarded as ignorant. Similarly, in Traditional Chinese Medicine, meridians are for tracing and describe the flow of life-energy and the relationship between energy and the physical body, and the relationship between organs. The physical existence of meridians cannot be found in the body as the orbits of the Earth cannot be seen in the sky.