What is dark matter in the universe What exactly is dark matter in the universe

Dark matter was proposed by astronomer Captan in 1922, and there may be an invisible substance in the universe. Dark matter does not interact with electromagnetic waves, nor does it reflect light, so it cannot be observed with any powerful telescope. However, there is still a lot of controversy about whether dark matter really exists or not, and we need to continue to explore.

Dark matter is a substance smaller than electrons and photons, has no electric charge, does not interfere with electrons, can pass through electromagnetic waves and gravitational fields, and is an important part of the universe. Dark matter is very dense but in large quantities, so its total mass is large, and they represent the amount of matter in the universe, of which less than 10% (about 5%) of the total matter in the universe is visible to humans. Dark matter cannot be directly observed, but it can interfere with the light waves or gravitational pull emitted by stars, and its presence can be clearly felt.

The earliest evidence for the existence of dark matter** is the observation of the rotational velocity of globular galaxies. Modern astronomy has shown that the density of the universe may be composed of about 70% dark energy, 5% luminous and non-luminous objects, 5% hot dark matter and 20% cold dark matter through gravitational lensing, large-scale structure formation in the universe, astronomical observations and expansive cosmology.

In physical cosmology, dark energy is an imperceptible form of energy that fills space and increases the rate at which the universe expands. The dark energy hypothesis is one of the most popular explanations of today's observations of the accelerating expansion of the universe. In the Standard Model of the Universe, dark energy occupies the mass energy of the universe.

Dark energy and dark matter are invisible energies that drive the movement of the universe, and all the stars and planets in the universe are driven by dark energy and gravity. According to the data collected by the Planck probe, scientists have a new understanding of the components of the universe, and the proportion of ordinary matter and dark matter in the universe is higher than previously hypothesized (30%), while dark energy, which is thought to be the mysterious force that causes the accelerated expansion of the universe, is less than expected, accounting for 73%. Dark energy is a milestone in cosmological research.

There are two main pieces of evidence in favor of dark energy. First, a large number of observations of distant supernovae show that the universe is expanding at an accelerated rate. According to Einstein's gravitational field equation, the phenomenon of accelerated expansion deduces the existence of "dark energy" in the universe with negative pressure.

Human beings have made very rapid progress in science and technology, from ancient times when they did not know the circle of heaven and earth to now they have successfully stepped out of the earth and into the universeWe still remember the classic phrase "This is a small step for you, but it is a big step for human progress", and at the same time we will wonder what is the relationship between the universe and dark matter? In fact, dark matter is a part of the universe, but it is hidden, let's analyze it.

The universe is filled with light matter and dark matter, and some material things we can't see are called space, but in fact space is not empty, it is all kinds of matter, and the so-called space is just the way of existence of material things. When we walk into the room, we are actually squeezing out other things and standing in their place, the universe is like this, large and small substances are squeezed around, matter itself is moving and changing, there is no reason for this, this is the original appearance of the universe in nature, we human beings and our thinking consciousness are also in motion and change, and there is no matter of things that do not move and change.

Dark matter is born in the universe. The relationship between the universe and dark matter is one of inclusion and containment.

Dark matter is an important part of the mass of the universe, and we can't see or touch it, but it does exist.

Dark matter occupies about 26% of the mass of the entire universe, and there is only a weak interaction force, which means that we cannot see or touch the existence of dark matter, and can only be observed indirectly, but dark matter exists around each of us.

Everyone has heard that there are nine planets in the solar system we live in, but in 06 Pluto was defined as a dwarf planet, so it was ranked outside the "nine planets", so now our solar system is eight planets.

Uranus among the major planets in the solar system is an outlier, such as the Earth, Venus, Jupiter and several others have their own orbits, and these trajectories are regular, but only Uranus, its trajectory can be described as weird, it never runs according to a fixed orbit, people simply can't ** its next trajectory, there will always be a trace of deviation.

The astronomers who observed this phenomenon at the beginning thought it was incredible, and it stands to reason that such a thing should not happen, so some people speculated whether there was a planet that was not discovered by human beings affecting Uranus, and then according to the irregular trajectory of Uranus, the astronomical telescope was adjusted to the position where they might have unknown planets, and sure enough, another planet was discovered, which is Neptune.

It is based on this discovery that people begin to realize that there are many things that you don't notice, but they are real. In 1922, there was an astrophyser Capttan, who deduced from the observation of the movement of celestial bodies in the universe that there was invisible matter between the celestial bodies, which was the first time that dark matter was proposed, although it was not proved to exist, but it also provided a direction for subsequent research.

In the following decades, a number of astronomers and astrophysicists have studied whether there is dark matter in the universe, through the study of various galaxy clusters in the universe, and through the very high-precision spectral measurement technology to measure the speed and distance of the stars at the edge of the galaxy cluster, it is found that the speed of those stars is constant, and through Newton's law of gravitation, those stars should move slower and slower because they are far away from the inner core of the galaxy and affected by the gravitational pull of the inner part of the galaxy. It can be inferred that the gravitational pull of the galaxy's core not only binds the stars in the galaxy, but also absorbs a lot of invisible matter around the galaxy's core.

With the gradual deepening of research, in the 1980s, there were many observational data supporting the existence of dark matter, and through the analysis of some observational data, it was found that the composition of dark matter is not any kind of particle that we know now, so many particle physicists now try to analyze the particle properties of dark matter through various high-tech means.

China's research on dark matter has not stopped, and it was built at the foot of Jinping Mountain in Sichuan, China's first extremely deep underground laboratory, which has a vertical rock thickness of 2,400 meters, which is also the deepest underground laboratory in the world.

Why should the lab be built deep underground? That's because above the surface, there are a large number of cosmic rays in our daily living environment, and this cosmic ray is the most feared thing by particle physicists. So a "clean" environment has a great impact on the observation of dark matter.

What matter is in the universe, before the 21st century, is a puzzling question. Ten years ago, it was only known that there was a sun, a moon, stars, galaxies like the Milky Way, and a cluster of galaxies made up of many galaxies. In fact, these visible celestial bodies account for only a tiny fraction of the vast universe, and most of the matter in the universe is invisible.

What are these invisible substances? It was only in the mid-90s of the 20th century that it was proposed that this is a singular substance called "cold dark matter", and this invisible matter makes up 90% (note that this figure is incorrect!). of the universe.

Stars, planets, humans, and normal matter such as atoms and molecules make up only a small fraction of the remainder. In isolation, this view seems quite true, but when you consider why stars and galaxies rotate so fast, the question arises. For example, the Milky Way rotates every 200 million years.

It's not dizzying, but it's powerful enough to tear the galaxy apart. The Milky Way is held together by the gravitational pull of matter, and after careful analysis, the gravitational force of matter that maintains the Milky Way is too weak to "strangle" the "wild horse" of the Milky Way spinning at high speed, unless there is a lot of invisible dark matter secretly exerting an additional force to "strangle" the members of the Milky Way. In addition, the galaxies in the galaxy cluster are also spinning rapidly, so what is the force that keeps the galaxies in the whole galaxy cluster together?

Is it also a lot of invisible dark matter? Now it seems to be exactly that!