Why do galaxies rotate in stars?

Rotation is one of the most basic properties of all things in the universe, galaxies and stars were born in the early days of the universe to produce gas clouds, those gas clouds rotate slowly under very small disturbances, so they have a certain angular momentum, gas clouds contract under the action of gravity to form galaxies and stars, in this process, the total angular momentum is conserved, so galaxies and stars will remain in a state of rotation.

Categories: Science and Engineering.

Analysis: There are two types of rotation: revolution and rotation. Souqiao.

Revolution is the gravitational force between the stars as a centripetal force. Otherwise, it is conceivable that there is acceleration between the stars, that is, the stars move in opposite directions, and the final result is that the stars collide, that is, in the universe, the unequal stars will sooner or later collide with other stars and be destroyed. As a result of this rupture of natural selection, most of the stars in the universe are orbital.

Of course, there will certainly be injustices now, but sooner or later they will be destroyed.

Rotation is due to the fact that stars and planets are formed by molecular clouds, which have a certain directional potential force when they are formed, so they must rotate. Even if the star does not rotate at first, as long as another object of considerable mass approaches, its gravitational pull will drive the planet to rotate in a certain direction without stopping (because of the law of inertia).

If galaxies rotate in one direction, does that mean that the entire universe is rotating? Why? It turns out that the direction of rotation of positive and negative space must be regular, there are clockwise and counterclockwise reasons, scientists are studying and exploring, but the known planets generally orbit like large galaxies, as for rotation, unless there are other reasons, besides, rotation belongs to the private affairs of planets, and the gravitational induction of large galaxies is generally not there.

Taking the Milky Way as an example, the rotation of the solar system is in the direction of one arrival, from west to east, is counterclockwise, the eight planets (except Venus and Uranus), the rotation direction of the rotation is one arrival, from west to east, but unlike the moon of the earth, the moon is for the service of the earth.

The Earth rotates from west to east so that the sun rises from the east, but the rotation and revolution of the Moon are synchronized, and the back side of the rotation is always not exposed to the Earth, and the rotation of the Moon is mainly tidal locked, while illuminating the Earth at night. Even for the rotation of Venus and Uranus, it is also counterclockwise, the direction of rotation is different, from east to west, there are many kinds of clockwise rotation of them, but they are not sure, I think, before the solar system combined, their rotation direction is different, the shape of centrifugal force has long been different, not so that the solar system, is determined by the big **.

It does not affect the gravitational pull of the sun, because the rotation of Venus and Uranus is still counterclockwise, as for the rotation interference of the gravitational pull of the sun, just like human beings, the gravitational pull of the sun has no effect on human beings, it is all their own private affairs, and their purpose of rotating clockwise from east to west is probably to hope that the sun will rise from the west. Angular momentum refers to the velocity at which the vector diameter of a particle sweeps through the region. In other words, if the vector diameter of a particle is smaller, its rotational velocity increases.

This is the conservation of angular momentum.

The Milky Way is thought to have been formed when a primordial supermassive black hole pulled into a huge cloud of interstellar matter. This mass of interstellar matter has had angular momentum since its formation. Then, due to some unknown interference, the star-making movement began, and one star after another gradually formed.

Interstellar matter shrinks as stars form, but angular momentum does not disappear in the process. So the Milky Way began to spin.

According to foreign ** reports, if you look closely at the model of the solar system, you may notice that the sun, planets, moons, and asteroids are all in the same plane. But why is this happening?

To answer this question, let's go back to about 4.5 billion years ago, when the solar system was just formed.

At that time, the solar system was just a huge, constantly rotating cloud of dust and gas, about 10,000 astronomical units in diameter (one astronomical unit is the average distance between the Earth and the Sun, about 100 million kilometers). Due to the large size of the cloud, although there are only dust and gas molecules, under the pressure of its own mass, it still begins to collapse and shrink.

As the cloud of dust and gas swirled, it became more and more flattened, like a pizza chef tossing dough into the air and spinning it into a cake. At the same time, in the increasingly flattened gas cloud**, all the gas molecules are tightly packed together, and the temperature becomes higher and higher. Under this extreme heat and pressure, hydrogen and helium atoms begin to fuse, facilitating nuclear reactions for billions of years, and a young star is formed – this is our sun.

For the next 50 million years, the sun has been growing, collecting gas and dust from its surroundings while releasing a lot of heat and radiation. As the sun grows, there is an open space around, like a doughnut jerk.

As the sun grows, the gas cloud collapses, forming a larger, more and more flat disk around the star.

Finally, the clouds form a planar structure that revolves around the star, called the protoplanetary disk. According to Hakijipur, the protoplanetary disk was thousands of astronomical units in diameter, but only one-tenth of its diameter.

Over the next tens of millions of years, the dust particles in the protoplanetary disk have been slowly spinning, occasionally colliding with each other, and sometimes even combining together, gradually turning into large particles a few millimeters long, and then into small stones several centimeters long. These small stones continue to collide and combine, eventually turning into giant celestial bodies. After these celestial bodies are large to a certain extent, they gradually become spherical planets and dwarf planets and moons under the action of gravity.

Other celestial bodies are irregularly shaped, such as asteroids, comets, and some small moons.

Although these celestial bodies are different in size, they are basically located in the same plane because their raw materials come from this plane. That's why today's eight planets in the solar system and other celestial bodies revolve around the Sun in the same plane.

If we want to know how this works, we have to go back 4.5 billion years. At that time, the solar system was in the stage of formation, and the bucket was relatively blurry, with a lot of dust and gas clouds. As the clouds of gas and dust rotate and collapse, the solar system becomes flattened and flattened, as if you were rolling dough.

After that, the temperature became higher and higher, and many gas molecules were packed together as they had never been, and then a qualitative change occurred, forming the sun. As the Sun grows larger, the gas cloud continues to collapse, and the area around the star becomes flattened and larger, becoming a large disk. Subsequent stars were formed around the disk, so many planets now rotate in the same plane.

The formation of a thing must be regular, and it is not achieved overnight. And the position of the planets in the solar system is also very well said, which is the one introduced above. In the beginning, the gas cloud was a relatively large dough, but as it rotated and collapsed in some places, the disk became flattened and larger.

And somewhere on the disk there is a sun, and it is a newborn sun. Other planets slowly appeared, all revolving around this flat structure. This disk, also known as the protoplanetary disk, is thousands of astronomical units in diameter, but only 1 10 times thick.

The foundations have already been formed, and for the next thousands of years, the planetary disks will continue to rotate, possibly colliding with some objects, and then reuniting. For example, after being just dust, it becomes a small particle, and when the small particle is combined with the small particle, it becomes a large particle. These large particles then turn into pebbles, which continue to collide and merge to form huge celestial bodies.

And these celestial bodies are also attracted by the gravitational pull of the disk, which becomes the picture we see today.

As can be seen from the above description, these planets did not have this situation after they were formed, but at the time of their formation.

The Spike and Source Solar System is a star system formed by the gradual aggregation of nebulae, and in order to form a solar system, nebulae need to be at least 100 million kilometers in diameter. Inside the nebula, there is a large amount of dust and gas, which through the action of gravity, begins to gradually accumulate. The collapse and contraction of the nebula caused a spin in the solar system**

The early nebulae gradually collapsed and contracted due to their own gravitational effect, and in this process, the matter collided and moved, and the angular momentum generated during the contraction was conserved, making the nebula rotate faster and faster.

The main reason is that the orbits of the planets are relatively small, so they appear to be rotating in the same plane.

The fundamental reason is that there is no gravity on the moon, they can float in parallel in a certain space, and they have their own orbit.