https://photos.app.goo.gl/t5NmSF2NWCnqKRi89 The chasing effect of the gravitational field will cause the expansion of the planet's orbit. The detailed derivation process is given in the link above. I checked some information. The planets in the solar system are gradually moving away from the sun. I can understand that their orbits are expanding. Does that mean that the chasing effect of the gravitational field is working? (There is also a saying that the mass of the sun is decreasing, but the rate of decrease should be very slow, and it is not enough to produce the effect of keeping the planet away from us to observe.) I also considered whether this violates the law of conservation of energy as time increases. On the surface, the energy of the planets will gradually increase by themselves, which violates the conservation of energy. However, we must note that the gravitational field provided by the sun is constantly increasing. The gravitational force is conveyed to the planet, which provides energy for the planet. Under the chasing effect of the gravitational field, the planetary energy increases and the orbit expands. I don't know if the same is true for the expansion of the universe, the idea is crazy.