Information about the mysteries of the universe

The universe is defined as space and matter outside the earth's atmosphere. In the universe, the earth is the only living planet known to mankind.

The creation of the universe:

At the initial stage of explosion, matter can only exist in the form of elementary particles such as neutrons, protons, electrons, photons and neutrinos. The continuous expansion after the explosion of the universe caused the temperature and density to drop rapidly. With the decrease and cooling of temperature, atoms, nuclei and molecules are gradually formed and combined into common gases. Gas gradually condensed into nebulae, which further formed various stars and galaxies, and finally formed the universe we see today.

Extension:

Dark energy accounts for 74% of all matter in the universe and is the driving force for the accelerated expansion of the universe. The expansion of the universe is in the balance of two forces, just like Yin and Yang. One force is gravity, which slows down the expansion, while the other powerful reaction is dark energy, which accelerates the expansion of the universe. Now it seems that dark energy has won. The visible matter in the universe is far from enough to connect the universe together. If there were no mysterious and invisible matter, the Milky Way would have fallen apart. Scientists call this invisible mysterious substance "dark matter".

Accelerate expansion:

Researchers have calculated that the current expansion speed of the universe, the so-called Hubble constant, is about 73.2 km/(one million parsec per second). Every/kloc-0.000000 parsec is equivalent to 3.26 million light years, so every time the distance between a galaxy and the earth increases by/kloc-0.000000 parsec, its speed away from the earth increases by 73.2 kilometers per second. This means that in 9.8 billion years, the distance between celestial bodies in the universe will double.

The end of the universe:

The laws of thermodynamics will not make the universe immortal. When new stars can't continue to form, the universe reaches the balance point of heat and silence, and the state of the universe is like the soup-like space-time at the beginning of its birth. Thermal silence is the end point of thermodynamics, and the temperature anywhere in the whole universe is only a little higher than absolute zero, which means nothing will survive. A few scientists believe that if the end of the universe is a big collapse, then all substances will eventually become atoms. After an accidental quantum fluctuation, a new round of big bang will be formed and the next universe will be born.

Extended data:

Solar system:

The solar system is a collection of all celestial bodies centered on the sun and constrained by the sun's gravity. Including eight planets (from near to far: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune? ), as well as at least 173 known satellites, 5 confirmed dwarf planets and hundreds of millions of solar system small objects.

Interplanetary matter:

In addition to light, the sun constantly sends out a stream of electrons, which is called the solar wind. The speed of this particle flow is 6.5438+0.5 million kilometers per hour, forming a thin atmosphere (solar circle) in the solar system, with a range of at least 654.38+0.000 astronomical units (heliopause), which is what we call interplanetary matter. The sunspot cycle of the sun, the frequent flash flames in the solar circle and the interference caused by coronal mass ejection have produced the space climate. The solar current sheet produced by the magnetic field rotating with the rotation of the sun in interplanetary matter is the largest structure in the solar system.

The earth's magnetic field protects the earth's atmosphere from the solar wind. Mercury and Venus have no magnetic fields, and the solar wind gradually draws their atmospheres into space. Near the magnetic poles near the earth, such as the South Pole and the North Pole, you can see the aurora produced by the interaction between the solar wind and the earth's magnetic field.

Cosmic rays come from outside the solar system, and the solar circle shields the solar system. The planet's magnetic field also provides some protection for the planet itself. The density of cosmic rays in interstellar matter is related to the intensity change of solar magnetic field cycle, so how much cosmic rays change in the solar system is still unknown.

Interplanetary matter gathers into cosmic dust in at least two disk-shaped regions. The first area is the ecliptic dust cloud, which is located in the inner solar system and is the cause of zodiacal light. They may be caused by the collision between celestial bodies and planets in the asteroid belt. The second region extends in the range of 10 ~ 40 astronomical units, which may be caused by a similar collision between celestial bodies in the Kuiper Belt.

References:

Universe-Baidu Encyclopedia