The perception that the universe appears to be moving while we perceive ourselves as stationary is due to a phenomenon called apparent motion or relative motion. It is a result of our observation from a particular reference frame.
When we say the universe appears to be moving, we usually mean that celestial objects such as stars, planets, and galaxies seem to be in motion relative to our position on Earth. This apparent motion can be attributed to various factors:
Earth's rotation: The Earth rotates on its axis, causing the celestial objects to appear to move across the sky from east to west. This daily rotation gives the impression that the universe is in motion.
Earth's orbit: The Earth also orbits around the Sun, which takes approximately one year to complete. As we move in our orbit, different parts of the sky become visible at different times of the year. This results in changes in our perspective of the celestial objects and contributes to the perception of motion.
Motion within the Milky Way: Our solar system is part of the Milky Way galaxy. The Milky Way itself is rotating, and our solar system moves along with it. This motion can cause shifts in our perspective of distant galaxies and other celestial objects over longer timescales.
It's important to note that while our perception might suggest motion, the fundamental nature of motion in the universe is relative. The concept of absolute rest or a fixed reference point is not applicable on a cosmic scale. The relative motion we observe is a consequence of our position within the dynamic and vast universe.