What is phase transition is to say that the origin of the universe is seen in one word

Phase transition refers to the sudden change of matter from one phase (state) to another under continuous changes in external parameters (such as: temperature, pressure, magnetic field, etc.), the most common being ice turning into water and water turning into vapor.

The transition of an object from one phase (solid, liquid or gaseous) to another is marked by a significant change in its physical properties and molecular structure.

The process by which a substance changes from one phase to another. The homogeneous part of the material system that has exactly the same physical and chemical properties and has obvious interfaces with other parts is called a phase. Corresponding to the three states of solid, liquid and gas, the substance has solid phase, liquid phase and gas phase.

The mutual transformation between different phases is called "phase transition" or "change of matter". The vast majority of the various substances that exist in nature exist in three aggregate states: solid, liquid, and gas. In order to describe the different aggregation states of matter, "phase" is used to represent the "phase" of the three forms of solid, liquid and gas of matter.

Broadly speaking, phase refers to a homogeneous part of a material system with the same physical properties, which is separated from the other parts by a certain interface. For example, in a system consisting of water and ice, ice is one phase and water is another. Iron, iron, iron, and δ iron are the four phases of iron crystals.

There are generally two types of mutual transitions between different phases, namely first-order phase transitions and second-order phase transitions. Intersection always occurs at a certain pressure and at a certain temperature. Phase transition is a common physical process of phase transition, which is widely involved in production and scientific and technological work.

In the process of mutual conversion of material forms, there must be inhalation or release of heat. The main differences between the three states of matter are the distance between their molecules, the magnitude of the interaction force between molecules, and the way in which heat moves. Thus, under the right conditions, an object can change from one state to another.

The transformation process is from quantitative change to qualitative change. For example, in the process of changing from a solid state to a liquid state, the solid substance continuously absorbs heat and the temperature gradually increases, which is a process of quantitative change; When the temperature rises to a certain level, that is, when the melting point is reached, and the heat supply continues, the solid state begins to transform to the liquid state, and then a qualitative change occurs. Although the heat is continued, the temperature does not rise, but the solids and liquids coexist until they are completely melted.

First-order phase transition When a phase transition occurs, there is a change in volume and the absorption or release of heat, which is called "first-order phase transition". For example, at 1 atm of 0, 1 kilogram of ice is converted into water of the same temperature, absorbing kilocalories and shrinking in volume at the same time. Therefore, the transition between ice and water is a first-order phase transition.

Second-order phase transition When a phase transition occurs, the volume does not change, nor is it accompanied by the absorption and release of heat Phase transition, but only the physical quantity of heat capacity, thermal expansion coefficient and isothermal compressibility coefficient changes, this kind of change is called second-order phase transition. The transition between normal liquid helium (helium) and superfluid helium (helium), between normal conductor and superconductor, between paramagnet and ferromagnet, and between ordered and disordered state of an alloy are all typical examples of second-order phase transitions.

Clausius, a physicist in country X, pointed out that the process of change of energy from non-uniform distribution to uniform distribution applies to all forms of energy and all events in the universe, and that in any given object there is a physical quantity based on the ratio of its total energy to temperature, and he named this physical quantity "entropy", and the "entropy" in an isolated system tends to increase forever. But there will always be regions of high "entropy" and "low entropy" in the universe, and it is impossible to be absolutely uniform. Therefore, the belief that when the maximum value is reached due to the continuous increase in the level of "entropy", the universe will enter a state of eternal silence, and finally die of "heat death", is a misconception that a part of the universe that we can observe now is the entire universe.

At present, the scientific community is more recognized as the great ** theory, but the specific cause cannot be verified. I am pessimistic that humans can solve such problems.

There are several opinions in the academic community, but there is no definite answer yet, and it is estimated that there will be no results for decades.

It all started with the cosmic explosion.

Friend, this question is too big. You also have to "use it urgently".

This is one of the world's top three problems. Countless scientists around the world are fighting for this. It hasn't worked out yet. You can't be in a hurry.

In the earliest days of the universe, that is, about 15 billion years ago, all the material world observed today was concentrated in a very small range, with extremely high temperatures and extremely dense The temperature of the universe was about 100 billion degrees Celsius, and the main components of its matter were light particles (such as photons, electrons, or neutrinos), while protons and neutrons accounted for only one billionth of a billion All these particles are in thermal equilibrium Because the whole system is expanding rapidly, the temperature drops very quickly Large** seconds, The temperature drops to 30 billion degrees Celsius, and the ratio of neutrons to protons drops from 1 to 0 61 After 1 second, the temperature has dropped to 10 billion degrees Celsius As the density decreases, the neutrino is no longer in thermal equilibrium and begins to escape outward The electron jujube positron pair begins to annihilate the reaction, and the ratio of neutrons to protons drops further to this point But the temperature is still too high, and the nucleons are still not enough to bind the neutrons and protons together The temperature of the universe drops to 3 billion degrees Celsius At this time, protons and neutrons can already form a temperature like deuterium, Helium-like stable nuclei Chemical elements begin to form at this time Thirty-five minutes later, the temperature of the universe drops further to 300 million degrees Celsius, and nucleus formation stops The mass ratio of helium to free protons remains roughly within this range Because the temperature is still very high, protons still cannot combine with electrons to form neutral atoms Neutral atoms began to form about 300,000 years after the occurrence of the big **, when the temperature has dropped to 3 000 degrees Celsius, and the chemical binding is enough to bind most of the free electrons to the neutral atoms By this stage, the main components of the universe were gaseous matter, and as the temperature decreased, they slowly condensed into dense gas clouds, and by 109 years later, various galaxies were formed, and in 1010 star systems were formed These star systems have undergone a long evolution to form the universe we see today

The realm of consciousness can reach everything you think, think? It depends on the individual's qualifications.

Supercritical water has special properties that are not found in the usual state of water

The universe has no origin, and the basis of human thinking is wrong, so we're always looking for things that don't have answers.

The universe has no sense of size But human beings measure it by their own volume The universe has no origin Origin is the product of chronology For the universe without a beginning, there is no end universe Big** is the origin, so there was no universe before the universe The universe is the limited definition of nature given by human beings Existence is the true definition of the universe What exists is known and what is unknown and what is eternal and infinite is the part of the universe that makes up the universe.

It's like standing in a certain alley in Xicheng District, Beijing, and saying that I know how big the earth is, that is, the space around the wall, not a joke, because the existence of the universe and the relationship between the earth and the earth are far more disparities than that, thinking under the proposition that existence is the universe, you will not ask how big the universe is, thinking under the proposition that existence is the universe, you will not ask about the origin, in fact, we are just discovering the scope of existence, historical limitations, material limitations can be surpassed, but the limitations of human species cannot be surpassed, as long as we are human beings The human mind will think about the universe, but that's a fundamental mistake, the universe exists, and it's far more than what we think it isI hope you understand that we are asking about the origin of the universe in the wrong way.

The universe originates from the mind, the mind is invisible, intangible, sizeless, weightless, the mind has no origin, no end, and will not disappear. It is the mind that creates the universe and everything it is.

For thousands of years, scientists have been searching for when and how the universe came to be. It is only today that scientists are convinced that the universe was formed by a large ** that occurred about 15 billion years ago.

Before the ** happens, the matter and energy in the universe are gathered together and condensed into a very small volume, the temperature is extremely high, and the density is extremely high, and then the big ** happens.

All the galaxies, stars, planets and even life that appeared in the universe were gradually formed in this process of continuous expansion and cooling. However, the theory of the universe that came into being does not yet explain exactly what existed before "the matter and energy that existed at one point"? The "Big ** Theory" was created by Gamow in 1946.

Before the formation of the universe was the gravitational singularity, a "point" with infinite density, infinite curvature of space-time, infinitely high heat, and infinitely small volume, at which all known laws of physics fail. Until the singularity expands beyond the limit, all states have no effect on the existing world, and it is impossible to deduce from the current state to the state before the singularity. It is the "vacuum energy" that causes the singularity to expand beyond its limit, the singularity expands, the universe appears, the inflation time is only 10 -34 seconds, and the space is thousands of meters, so the inflation is faster than the speed of light.

After that, the entire universe was big ** (there was no explosion in the big **), the universe officially began to expand, and celestial bodies were created.

Now most of the scientific community agrees that the universe came from a cosmic maximum, and that the universe has been expanding since that moment, and it is expanding at an accelerated rate. The current universe is still relatively young (in terms of the time it was formed), and the universe may last for hundreds of billions of years.

Now we see that most of the universe is stars, the burning of stars converts matter into energy and throws it into the depths of space in the form of light, we know that any energy will run out one day, when the vast majority of stars burn up and become white dwarfs, neutron stars, or black holes, then the universe will no longer expand and begin to collapse, the universe will become smaller and smaller, the galaxies will be closer and closer, the black holes of each galaxy will merge into one or several super black holes, and countless super black holes will merge into larger supersuperpowers and black holes, Eventually, all the super-super black holes converge to form a super-cosmic egg, which will absorb all the matter and energy (light) of the universe, and the internal temperature will become higher and higher, and it will begin to give birth to another cosmic **.

Current speculation: the universe is big ** said.

Large** may have been another physical universe before.