Lead
If "silence" is used to describe the state of the universe, such a feeling is not appropriate.
Like the Earth, everything in the universe is in constant motion, from small stars to the Milky Way, and even to the expansion of the universe and black holes.
The speed of these movements often surprises people, such as the speed of the stars near the black hole, which can even reach 10% of the speed of light.
Sadly, we don't get to see these speedy movements because they are so far away from us.
And there is a fact that is far beyond our imagination: the sun itself flies out at a speed, and the speed exceeds 800,000 kilometers per hour.
But it is impossible for such a fast speed to leave no traces, so why do we look at the sky on Earth and the stars we see seem to have not changed until next year, to decades from now?
1. Stars are navigational tools.
In fact, in ancient times when science and technology were not developed, human beings cherished the stars in the night sky very much.
Aside from the fact that they can provide us with a small amount of light at night, allowing us to distinguish the sky from black holes, what really matters is that the stars are also the earliest navigation tools for humans.
Before the invention of the compass, seafarers relied on the stars in the night sky to determine the direction of their ship, so that they could go all the way to their destination east or west.
It can also be seen that the stars in the night sky have been very important to human beings since ancient times.
But in modern times, with the continuous development of science and technology, the importance of stars has been decreasing, and even until modern times, you can't see a picture of someone holding a telescope and staring at the night sky to find the North Star.
So, how did these sailors who relied on the stars in the night sky to determine their direction do it?
Actually, it's through the "Star Map".
If you take out a modern star map at night, you can easily find the North Star from the sky, and you can easily find the North Star through the Big Dipper.
Then judge your direction by the dark colors, the stars, and the positions of the various zodiac signs.
But in the time of the ancient sailors, there were no modern star charts, so they had to rely on their own experience to judge.
In their memory, the stars are fixed, so they just need to remember the position of the last constellation they saw in the morning when they are on the shore, and then they can walk all the way to find their way.
But in fact, there is a certain potential for this approach, that is, on this route, there is no change in the stars, or no slight change is imperceptible to the sailor.
2. The movement of the earth around the sun.
But there is a more fundamental premise that even the stars in the night sky that we see are fixed in their true positions.
This requires us to see how it moves.
In human perception, the sun rises in the east in the morning and sets in the west.
This leads humans to mistakenly believe that we are "watching" the sun spinning.
But what we actually feel about the movement of the sun is the effect of the movement of the earth around the sun, that is, the earth constantly moves around the sun from west to east.
Such a sport will allow us to see some changes in the stars we see every day: the sun that rises early will obscure some of the stars, but at night, before rising, we can see the stars that are "obscured" by the sun before rising.
That way, if you want to tell if there's land in the direction you're going, you just have to look for this particular brightness on the horizon as you see it from the boat.
In the early days, this phenomenon was called dawn and dusk, but it also raises the question: how is time determined on Earth?
Because if you're somewhere else, you might have to judge the time a little earlier or a little later.
Because the earth is perceived by humans, it is true that more stars will move in the sky in the morning.
But in modern times, we have satellites, and we have taken videos of the rotation of the earth, and we see that the earth is indeed rotating around its center, but the speed of rotation is actually very slow.
As a result, the stars you see at night on Earth are mostly the same as those you see during the day.
But this speed, although it is considered slow, is actually very fast, and every day we see different stars, but we don't feel it.
Because these are so far away from us, they move much less in the space of days, months, or even years, which leads to the fact that you can't perceive these movements if you are not observing them over an extremely long time span.
But the fact is that they are constantly moving: the Earth's orbit is named the ecliptic orbit, which is one of the three most important orbits in the solar system, the other two being the equatorial plane of the Sun and the heliocentric equatorial plane.
But the sun does not move perfectly regularly around the Pacific section of the solar system, but keeps swinging, so that the earth is swinging up and down while moving around the sun.
In this way, when we observe the night sky, the stars we see are also affected by the orbit of the sun, and there will also be an oscillating orbit.
And although the star itself is actually small, if you observe a large enough number of stars, then you will be able to see the difference between the two orbits and find the orbit in the night sky.
3. The speed of movement is too slow.
But the stars we can see in the night sky are only a few hundred or even a thousand carefully selected, and out of the hundreds of millions of stars, that's just a tiny.
Of the number of stars that can be seen with the naked eye, if you want to find out which stars are in the solar system, you have to look very carefully.
And on such a small basis, it will take a lot of time for you to see the position of these stars change, it will take hundreds of years, even thousands of years.
On the other hand, the number of stars that humans could see, or see, unchanged before, was very rare, and now, due to the acceleration of pollution and urban construction, we can see even fewer stars, which makes it even more difficult for us to see the changes in the position of stars that may exist that cannot be seen by previous humans.
In addition, the stars in the night sky are actually a very chaotic combination, and the stars you can pick are most likely two or three thousand light-years away, such a distance, even at the speed of light, from his position, we can't feel it, let alone their speed is very fast.
epilogue
But in reality, although the starry sky we see in the night sky is relatively stable, everything in the solar system is moving at high speed.
Every star we see is flying out at a rapid pace, and in order to slow down the passage of time and allow us to cherish the existence of this vein even more, we should observe this more solemnly.