What are dark matter and dark energy

So far, physicists and astronomers have constructed a variety of models of the universe based on observational facts and theoretical speculations, the most successful of which is the large ** universe model, and it is also a recognized fact that the universe is expanding at an accelerated rate. Whereas dark matter is an imaginary substance based on the existing theory of gravity, dark energy is an imaginary energy based on the existing cosmic model.

The existence of dark matter and dark energy can explain a series of troubling astronomical observations, and can also explain the evolution and existence of the universe well under existing theoretical models, but no experiment has directly detected dark matter and dark energy and descriptively described their existence. However, many new observations point to the same fact: dark matter and dark energy are real.

Physics' description of the nature of matter has been moving towards two limits. One is the microscopic limit, which has now penetrated deep into the nucleus; The other is the macroscopic limit, which has now expanded to the entire universe. Microscopically, most of the particles found so far can be explained by the Standard Model, which is also based on matter on Earth, particles produced by colliders, and cosmic rays; But when human beings extended their tentacles of exploration into the vast expanse of the universe, they discovered some puzzling phenomena.

From the 30s to the 70s of the 20th century, many scientists found that the gravitational mass was much larger than the photometric mass of galaxies when observing different galaxies. Since then, scientists have pointed out that there is a large amount of invisible matter in the universe - if only visible matter is involved in gravitational interactions, then the speed of rotation from the center of the galaxy to the spiral arm will become lower and lower as the radius increases. According to astrophysical theory, this leads to the instability of galaxies.

We can also simply come to this conclusion by using the formula of gravitational circular motion that we have learned in middle school physics.

However, actual observations show that the rotation speed of the spiral arm of a stable galaxy shows a constant velocity with the increase of radius, so that the galaxy can remain stable. This phenomenon also shows that most of the mass of galaxies is not concentrated in the center of the galaxy, but there are many invisible "dark matter" distributed throughout the galaxy, and the visible matter is only a small part of the mass of the galaxy.

We know that since the development of physics, although theoretical physics has been completely independent, whether the theory is correct or not must ultimately be tested by reliable experiments, and theory and experiment complement each other. Although the proposal of dark matter is only the brainstorming and mathematical calculation of scientists, it is of great significance for human understanding of the universe. As for whether the theory will be confirmed or overturned in the end, it still depends on specific experimental detection.

Hello! "What is dark matter and dark energy" Dark matter is a kind of matter that does not interact with electromagnetic forces, so you can't see him, you can't touch him, and you can't directly observe his existence, for us, dark matter is very similar to the ghost we know, even if we can't feel him, but he still plays a very important role in the universe, dark matter itself has mass, he will produce gravity, and his content in the universe is more than ordinary matter, and his job is to build the universe we are familiar with, such as galaxies. The gravitational force generated by dark matter will stabilize the galaxy to make up for the lack of galactic matter that is not enough to maintain itself, and in the distant space, those vortex, spherical, and irregular galaxies are aggregated by dark matter, and dark matter is somewhat similar to the skeleton of the universe structure, without which the universe will collapse and disintegrate.

Examine ** Dark energy is an unknown but pervasive energy in the entire universe, he is the opposite of dark matter, he will not build the universe, he will separate, tear apart the universe, his appearance is to explain the phenomenon that today's writers have discovered that the universe is accelerating expansion, since the birth of the universe, the speed of the expansion of the universe should be slowed down, but the universe is accelerating the expansion, so scientists deduce that there is a magical energy in the universe, which will push away matter, the origin of dark energy. In contrast to dark matter, dark energy is not proven, and dark matter is indirectly observed in the relationship between the light of distant galaxies that is distorted by the gravitational pull generated by passing through the dark matter (which does not mean that dark matter has been confirmed). Dark energy and dark matter can determine the future of the universe, if dark matter wins over dark energy, the universe will shrink, and when dark matter loses to dark energy, the universe will expand at an accelerated pace until everything is torn apart from each other.

View**.

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.

The upstairs is confusing at first glance, and let me tell you: dark energy is in dark matter. (For example, when you eat, you are absorbing energy from matter), and matter contains energy.

That is, matter and energy are one. There is no matter that has no energy, so there is no energy without a substance, and energy is contained in matter. Dark matter is also ...

What is dark energy? Let's give you an analogy, if you want to build a mountain (mountain stands for positive matter, which is the antonym of dark matter), and you use the excavated soil to build the mountain, then you are not only piling up the mountain, but also digging a pit. (The pit represents dark matter).

And the positive and negative accumulation of these energies is just zero... I don't know how to chase, I hate people who don't chase, hurry up, chase and chase-

Dark matter is an invisible substance that may exist in the universe as a theoretical proposal, which may be the main component of the matter in the universe, but does not belong to any of the currently known substances that constitute visible celestial bodies.

Dark energy is a type of energy that drives the movement of the universe. Neither it nor dark matter absorbs, reflects, or radiates light, so humans cannot directly observe it using existing technology.

Dark energy is a force (energy) produced by dark matter (just like the Earth, gravity,).

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"Planck"With the data collected by the probe, scientists have gained a new understanding of the components of the universe, which contains a higher proportion of ordinary matter and dark matter than previously assumed (30%), and dark energy, which is thought to be responsible for the universe.

Dark energy is a force (energy) produced by dark matter (just like the Earth, gravity,).

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"Planck"With the data collected by the probe, scientists have gained a new understanding of the components of the universe, with the proportion of ordinary matter and dark matter in the universe higher than previously assumed (30%), and dark energy, a mysterious force thought to cause the accelerated expansion of the universe, is less than expected.

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 equations, the phenomenon of accelerated expansion deduces that there is a negative pressure in the universe"Dark energy"。

Dark matter (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. All.

The difference between the two:

1.Dark matter refers to non-luminous matter that is inferred from astronomical observations to exist in the universe. It is composed of non-luminous objects, halo matter, and non-baryonic neutral particles.

2.Dark energy refers to a kind of energy that fills space with negative pressure, and is currently a kind of energy **speculation about why the universe expands.

The same for both:

Scientists have put forward a variety of hypotheses about the properties of dark matter and dark energy, but they have not been fully proven until now.

The handling of a large section is not interesting, or the subject himself works hard to do an in-depth understanding, as follows:

Dark matter data.

Dark energy data.

The uncertainty principle, which relates to entropy, Bronke quantum theory.

Cosmologists like to model everything as so-called"Perfect fluid"What is the perfect fluid? It is a substance with density and pressure, and nothing else. In other words,"Perfect fluid"Non-sticky, it is not sticky, there is no internal stress, its pressure is the same in all directions.

In short, as far as cosmologists are concerned, the density and pressure of matter perfectly represent the characteristics of the universe.

Therefore, the ratio of pressure to energy density is just a simple number. It is not measured in meters, feet, seconds, pounds, etc., it is just a so-called dimensionless number, which is usually represented by the letter w.

That's where cosmologists think simply: that's all they care about, and all sorts of matter are characterized by this w, which is the ratio of pressure to energy density. For example, something that is not stressful is just so-called"Dust"。

Here, of course"Dust"It's not the same as you know. A galaxy of stars is dust (more or less) because as far as cosmic scientists are concerned, billions of stars behave like dust particles, i.e. as a medium with negligible pressure.

In today's universe, something greater than 0 can be ignored because the density of this matter decreases very rapidly; Therefore, even though there was a large amount of this kind of stuff in the past, it has been diluted to a state close to nothingness. This leaves a negative pressure substance, especially one with extreme negative pressure, w = -1. These substances have a very peculiar property:

Therefore, we ask a simple question: how much matter and what kind of matter is needed to reach the critical density, and also to match the other observed parameters of the universe? It turns out that we need about 30%."Dust", the remaining 70% must have extreme negative pressure, w = -1.

The missing matter (the difference between 30% and less than 5% as we know) is called dark matter, and the remaining negatively pressurized matter is called dark energy.

I hope this explanation helps you understand dark energy, all of which is backed up by a fairly solid, rigorous math and physics; But at the same time, we don't have the slightest clue what exactly these dark matter and dark energy are.

There are theories that dark matter may be"wimps"(weakly interacting megaparticles), or whatever. As for dark energy, it may just be an artifact of the so-called cosmological constant; or the potential energy of the so-called scalar field; Or maybe it's just quantum vacuum energy (although when we tried to calculate it, we found that we deviated by dozens of orders of magnitude, which is rather embarrassing).

So now,"Dark matter"with"Dark energy"Just words used to mark our ignorance. But at least we know them"Equation of state", the ratio between their pressure and energy density, the number w.

World objects are divided into 3 common forms, gaseous, liquid, and solid.

There are also 3 special forms, the light state, the energy state, and the last one is the most special, the dark matter state. In fact, these six forms are related.

Relationship: (Object state) Solid, liquid, vapor state, we become the object state, the relationship between the three is easy to understand, but it is a simple transformation of the form of the object, and it is also very common.

So what about the light state, in fact, objects can emit light, but you can't see it, some are red, some are green, blue, sunlight is a special synthetic light. The light state is a kind of normality, just like the glaze, a high-radiation object, in fact, what is radiated is the electron, which is a manifestation of the light state. People can also have radiation, but you haven't detected it yet.

This is the state of light, which is very common, but you ignore it.

The energy state is a second-order form, and the light state and the object state mentioned above are both first-order forms. The energy state is a special form, but it is also related to the first-order form, which is expressed in Einstein's formula e=mc 2.

The dark matter state is converted from the energy state after releasing all the energy, this dark matter state is referred to as the dark state, the dark state itself has no energy, and there is no mass, but there is a characteristic that it absorbs energy, which is a third-order form.

All objects in the universe cannot be transformed into nothingness, but only change form.