How do you explain the immobility of Polaris?

My understanding is that the distance between the earth and Polaris is too far, so I ignore the movement. It is equivalent to me walking around my desk, and you can see it in Beijing (assuming you can see it). Because my moving distance version is much smaller than your observation distance, my movement will be ignored by you, that is, I can't do anything about you. ?

There is a famous constellation called Ursa Major in the northern sky. It is the brightest and most important constellation in the North Pole. The constellation Ursa major has seven bright stars, which are arranged in the shape of spoons in the sky, much like ancient spoons for holding wine, so it is called the Big Dipper, also known as the Big Dipper.

Stars are not static. If you look at the sky every once in a while, you will find that these stars will move from east to west. Only one star is stationary, and all the stars in the sky are revolving around it. This stationary star is called Polaris. Polaris is located at the northern end of the earth's axis, which is five times as long as the extension line connecting Tian Xuan and Shu Tian in the Big Dipper. Because the earth rotates, Polaris is just on the axis of celestial rotation, so it is relatively static.

Polaris is about 434 light years away from the earth, with a diameter of about 52 million kilometers, and its mass is slightly more than four times that of the sun. It is a star with stable brightness and position that can be seen in the night sky.

Indeed, it seems to be static, but it will still change.

Don't move because the earth rotates around the earth axis, and Polaris is on the north extension line of the earth axis, so when you look at the sky at night, Polaris is motionless, and it is north overhead, so you can indicate the north.

In fact, Polaris will change, because the earth's axis of rotation is also slowly swinging periodically. Therefore, the position of the sky referred to by the north pole of the earth's rotation axis naturally changed. Astronomers have made it clear for a long time that 4800 years ago, Polaris was not the present alpha star of Ursa minor, but the alpha star of Draco called right pivot in ancient China. At that time, the right fulcrum won the honor of Polaris. By the year 1000, that is, in the early years of the Northern Song Dynasty in China, the sky referred to by the North Pole of the Earth was 6 degrees away from the current Polaris, that is, Alpha Ursa minor.

It can be seen that it was far from Polaris. At present, the north pole of the earth's rotation axis points to the sky, and the angular distance from Alpha Ursa minor is only about 1 degree. At present, the sky pointing to the north pole of the earth's rotation axis is approaching Ursa minor at the speed of 15 arc seconds per year. By AD 2 100, the angular distance between the sky indicated by the north pole of the earth's rotation axis and the alpha star Ursa minor was the smallest, only about 28 minutes. It seems that its "status" reached the peak of Polaris at this time. In the future, the sky pointing to the north pole of the earth's rotation axis will gradually move away from Ursa minor. By about 4000 AD, Cepheus Gamma will become the North Star. Around the year 14000, Alpha Lyra, Vega, will gain the reputation of Polaris. At this time, people talked about the story of the Cowherd and the Weaver Girl. Vega's position as the throne of Polaris far exceeds that of Cowherd. The time for the earth's rotation axis to swing like this is about 26,000 years. This shows that everything is in motion, stillness is only temporary and relative, and the change of motion is eternal.