Why are there so many planets in the universe?

Set off fireworks, and the other user will send him back.

The question arises from why the matter and structures in the universe come from

I can only use the explanations I see in the book

At the beginning of the universe, there was an orderly and flat expansion, but small differences in energy density caused certain areas to start to become different from their surroundings, and these tiny ripples caused "elementary particles" to come together to form various structures

According to the principle of gravitational instability: the otherwise uniform distribution of matter becomes more and more inhomogeneous under the action of gravity due to small disturbances (the poor get poorer and the rich get richer). Thus the structure is formed, and different celestial bodies are formed in different regions of density.

Of course, there are many ways to form planets, many of which are the remnants behind stars and the convergence of cosmic dust.

As of November 22, 2007, a total of 252 extrasolar planets have been discovered. This number is still too small because the planets are extremely difficult to observe. See.

It is most likely due to the accumulation of small stones in the universe over a long period of time. Over time, it became a planet.

We all know that there is a difference between stars and planets in the universe, and we all know that stars are much larger in mass and volume than planets. For example, the sun and the earth we are familiar with, the sun is a star, and the earth we are in is a planet. But someone just raised a question:

The universe is so big, could there be a planet bigger than the sun?Before we ask this question, we first need to know what a star isWhat is a planet again?

Speaking of stars, we have to mention the sun that we are all familiar with, the sun in our cognition is a huge mass of fireball, it is emitting powerful energy all the time, and even the energy intensity emitted by the sun warms the earth, we can't even look directly at the sun. Stars are theoretically spherical light-emitting plasma held together by gravity, and their light can be transmitted far, far away. When we look up at the starry sky, we see a star, and every star in it is a star.

Stars are also gaseous planets, and we can find similarities in the sun. Solid planets (such as the Earth) have a solid surface, while the Sun and other stars do not.

When it comes to planets, the Earth is a planet, and most of us think of it as something like this: the Earth revolves around the Sun, and the Earth itself doesn't emit light. In fact, these impressions include scientists' definition of planets, which usually refer to spherical objects that do not emit light and orbit stars.

The Moon we see is not a planet, the Moon is just a satellite of the Earth, and the light it emits is also the light that reflects the Earth and the Sun.

Planets include gaseous planets and solid planets, and gas planets are generally much larger than solid planets, such as taking the eight planets of the solar system as an example: Earth and Mars are solid planets, while Jupiter and Neptune are gas planets. Although there is a slight difference between the planets, as long as they revolve around a star, they are all called planets.

After knowing what stars and planets are, we can summarize what are the differences between stars and planets:

To sum up, we can now ask the original question: Are there any planets in the universe that are larger than the sun? The answer is no, and there is an incomparable gulf between stars and planets in terms of mass alone.

Scientists have discovered a "super-Earth" 6 light-years from Earth, which is three times more massive than Earth, but this is simply not comparable to a star like the Sun. And what if it's a gas planet? Gas planets are generally more massive than solid planets, for example, the gas planet Jupiter in the solar system is 318 times the mass of Earth, but it is only one thousandth of the mass of the Sun.

So what if there really was a planet with a mass of the Sun's magnitude? Assuming that this happens, then the state of this planet must be very different from that of a normal planet, and we would like to congratulate it on its upgrade to a "star". Although this is hypothetical, it is important to tell you that the mass of a planet is greater than that of a star will not and cannot happen.

According to current theories of planet formation, planets formed at about the same time as the stars that revolve around them. For example, in our solar system, the sun has been born for 5 billion years, while planets such as the Earth have been born for about 4.6 billion years.

Both stars and their planets are formed in a large cloud of interstellar gas. Interstellar gas clouds are usually stable, but once they are disturbed by gravity, such as a nearby supernova explosion.

or gravitational waves in the distance.

When the radiation reaches the interior of the interstellar gas cloud, it becomes unstable, and the material in it may concentrate towards a slightly higher density, and the process is irreversible. It's that once the process starts, it can't be stopped.

As matter is concentrated, the density of matter in the middle is getting higher and higher, the gravitational pull is getting stronger and stronger, the rate of matter concentration is getting faster and faster, and the volume of clouds is getting smaller and smaller. In this process, due to angular momentum.

Conservation principle, very weak deflection forces also form stronger and stronger rotational forces (rotational angular momentum), in angular momentum and centrifugal force.

As a result of gravity, the cloud gradually forms a discus shape that is thick in the middle and thinner towards the edges. Eventually, at the center of the discus, a star will be formed that concentrates the vast majority of the mass of the cloud, and next to it, some sub-centers of mass will be formed.

and form two planets with a small mass, but with most of the rotational angular momentum of the clouds, which are planets.

There are so many stars in the universe that according to this theory, there are several planets next to each single star. But next to a relatively close binary star (close binary), the formation of a planet is not very likely. Even so, scientists speculate that in the Milky Way.

, the number of planets will not be less than the number of stars, but because the mass of the planets is too small compared to the stars, and they do not emit light, they are difficult to detect.