Why are galaxies disk shaped? Why are all planets round?

This is the law of nature in the universe, and like the solar system, any matter has its potential energy, which tends to be lower and more stable. And on the same plane it is possible to overcome the excess energy that it has to expend.

Another definition of entropy is that the degree of chaos tends to be more stable as it is.

The so-called water flows downward. Most of the stars in the galaxies' oblate sphere spiral galaxies either orbit in a conventional orbit around the core of the galaxy (the nucleus), or the oblate spheres of the galaxies clustered in the oblate sphere revolve around the core of the galaxy. However, these formed oblate globular halos, or galactic oblate spheres, are concentrated towards the center of the galaxy.

The orbits of these constellations are still disputed, and their directions can be clockwise or counterclockwise, perhaps in orbits with high angles of inclination, or in irregular orbits, to name a few. The stars in the halo may come from outside, or they may come from other galaxies because they are swallowed by galaxies. For example, the Sagittarius dwarf ellipsoid galaxy is the object of the Milky Way's ongoing galactic devouring, and observations have shown that some of the stars in the galactic halo come from the galactic spheres.

Unlike the disk of the galaxy, the interstellar dust in the halo of the galaxy seems to be free, and further comparison, the stars in the halo are all of the second family, very old, and have a much lower metal content than their relatives in the disk of the galaxy (more like the nuclear sphere). There are also many globular clusters in galactic halos. Halo stars occasionally pass through galactic disks in motion, and some red dwarfs near the Sun are considered members of galactic halos, such as Captan and Groombridge 1830.

Because their motion around the center of the galaxy is irregular, these stars often exhibit anomalous self-phenomenon.

There are also spherical ones, but there are very few. In fact, most galaxies may have a huge black hole at the center that devours everything around them, so the galaxy is spiral-shaped.

The reason why the planets are all round comes from gravitational conditions. The state of an object is generally in several different forms, such as solid, liquid, gaseous, and plasma. The lower the temperature, the smaller the vibration amplitude, the greater the binding force of the object, and the whole is solid; If an object has a high temperature, the molecular motion accelerates, and the binding force between each other becomes smaller, it is easy to appear gaseous, liquid, or plasma.

When the diameter of these solid or liquid objects reaches the aforementioned 500 kilometers, the centripetal gravitational attraction is generated due to the large mass of the object, and the greater the mass, the greater the gravitational force. And this gravitational force is evenly distributed, which forms the state of the planet's circle.

Negative example:For comparison, look at asteroids. Smaller planets tend to be round.

In fact, they are jagged, fragmented, or other irregular shapes. This is because smaller asteroids have only a very weak gravitational pull, which means that they do not attract matter in the same way in all directions.

Why are galaxies mostly disk-shaped and not spherical?

A galaxy is a type of celestial system, usually a system that consists of countless star systems (including the self of stars) and dust (such as nebulae, etc.). For example, the solar system where our earth is located belongs to the galaxy of the Milky Way, the diameter of the Milky Way is about 8 to 100,000 light years, and it is a medium-sized spiral matching galaxy.

Our understanding of galaxies should mainly come from the Milky Way, and it is true that the shape of the Milky Way is like a huge "disk", with a thick middle and relatively thin edges, so are all galaxies disk-shaped? Of course not, there are several types of galaxies in the universe, the first is elliptical galaxies, elliptical galaxies are perfectly circular or elliptical in shape, bright in the center, darkening at the edges, with dense cores of stars, and many globular clusters on the periphery, and elliptical galaxies are divided into giant and dwarf.

Elliptical galaxies. The second type is the Lun Vortex Galaxy, which accounts for about 30% of all star coefficients, and they have a relatively round core with two or more Lun arms extending from the core, and the Milky Way is a Lun Vortex Galaxy. The third type is irregular galaxies, which do not have a nuclear sphere and do not have a boom structure.

Many irregular galaxies are small in mass and oddly shaped, often leaving some traces of the disappearance of the boom. The fourth type is the lenticular galaxy, which is between elliptical galaxies and spiral galaxies, and lensed galaxies are galaxies in which disk galaxies have exhausted or lost most of their interstellar material, and only a small number of stars are forming in progress, dominated by older stars. In terms of spherical shape, elliptical galaxies are the closest to spherical galaxies.

Irregular galaxy NGC4485

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Because in the process of forming these galaxies, there will be a lot of planets, and when these planets are high on the same plane, Zhinian Kai will form disk-shaped galaxies.

This is related to the position of the galaxy in the universe and the gravitational attraction it is subjected to, which is more suitable for the existence of galaxies in the universe.

Because galaxies are formed by collisions, most are disk-shaped.

Since the shape of the solar system is roughly this when viewed from the outside, it can be closer to the image.

I think this is a natural phenomenon, and Yu Qiao and this matter is still under investigation, so we must look at it rationally, but I believe that the researcher and the destroyer will definitely give us an answer.

Because this is the first freeze-frame state of the galaxy, it is not observed from multiple angles, so it will only be this shape.

According to astronomers, there may be one in our universe2 trillion galaxies, 200 trillion planets。AbsolutelyThere are still very few planets that humans can observe.

The observable line of pure fiber chain stars, allRound in shape, not found yetA square or polyhedral planet。Planets are round celestial bodiesIt is related to the early formation of the planets, as well as the rotation and revolution of other planets

Planets are generally made ofMatter after a supernova explosioncomposition, and these substances areA molten substance, which can be thought of as a very hot liquid. At first, the star will absorb most of this material, and when the star has absorbed enough material, the remaining material will form some planets, such as the formation of the solar system, which is the sun that first absorbs 99% of the material after the supernova explosion.

After the first planets had their inner cores, they began to continue to existAbsorbs cosmic dust and gases, and constantly rotating, the volume and mass began not only to increase. Due toGravity is always directed towards the center of the massThe substance is squeezed in all directions, this planet eventually forms a sphere.

When the planets are basically formed and begin to cool, the whole sphere slowly becomes oneThe surface is solid, and the core is a sphere of red-hot liquid。And because of the strong gravitational pull of the star,Starts to orbit the star while rotating, then this time is not a perfect circle, butSlightly elliptical, just like the 8 planets of the solar system, almost all of them are oval.

Planets revolve around starsThe faster it goes, the more elliptical it becomesThis is because the planets are affected by their own centrifugal forces, pushing the material on their equator outward, so some planets have some uplift at the equator.

In addition to the eight planets of the solar system, which are elliptical, the planetary grandchildren that can be observed in the Milky Way are basically the same.

But numerousAn asteroid is not necessarily a vertical circular objectSome asteroids in our solar system are presented with strange appearances, and it is said that there are dumbbell-shaped asteroids.

Because the distance is too far, so there will be such a phenomenon, such as the number of wild fruits is close, we will not have such a recognition of the potato sleepy shouting, but will be blind to see the whole picture.

Because the distance is very far, and secondly, because of the refraction of light, it looks round.

The planets are affected by their rotation and gravitational pull, and the planets are collided in the process of orbiting.

Because the planets rotate and revolve, the planets are round, so we look round.

The gravitational pull of the planetary mass pulls all its matter towards the center, eliminating any discordant circularity.

Many of the smaller celestial bodies in the solar system are not circular because their gravity is not strong enough to smooth their shape.

The gravitational pull of the planets pulls evenly from all directions. Gravity pulls from the center to the edges, like the spokes of a bicycle wheel. This makes the overall shape of the planet a sphere, i.e. a three-dimensional circle.

Due to its massive body and the internal heating of radioactive elements, the planet behaves like a fluid and will succumb to the gravitational pull of its center of gravity for a long time. The only way to get all the masses as close as possible to the center of gravity of the planet is to form a sphere. The technical name for this process is "isostatic pressure adjustment".

For much smaller objects, such as the 20-kilometer asteroid seen in recent spacecraft images, the gravitational pull is too weak to overcome the asteroid's mechanical strength. Therefore, these objects do not form spheres. Instead, they maintain an irregular, fragmented shape.

Planets form when matter in space starts colliding and clumping together. After a while, it has enough to generate a lot of gravity. This is the power that holds matter together in space.

When a planet is forming is large enough, it begins to clear the path of the stars orbiting it. It uses its gravity to capture something space.

Saturn. The faster it rotates, the less round it becomes. Then, as it cools and hardens, it retains that shape. If a molten planet starts spinning faster, it becomes less round and has larger bulges.

The planet Saturn is very flat and non-spherical because it rotates very fast. All the planets are round due to gravity, and since they rotate at different speeds, some planets have fatter equators than their poles. So the shape of the planet and the speed and direction of its rotation depend on the initial conditions of the material in which it is formed.