Does the universe have an end?

The universe is similar to a Mobius belt (twisted two-dimensional space) or a Klein bottle (two Mobius belts are glued together along their only side), except that the universe is a twisted three-dimensional space, that is, there is no door that can never get out, but there is no end, or we will find ourselves back to the starting point if we keep going forward!

Two thousand years ago, the Roman philosopher Lucretius once said that there was a contradiction in this question. If the universe really has an edge, then there must be something outside it that can tell us that it has reached the edge. But this is impossible, because the universe should contain everything. However, the universe does have edges. Because the universe is constantly expanding, celestial bodies are far away from us at the speed of light and disappear into our sight in some places. This dividing line is the visible universe.

Einstein's theory of relativity once said: the universe is finite and infinite! Relativity is a theory of comparative philosophy. Read more and you may find the answer you want.

There is also a world (macro), and the universe contains everything. There is nothing outside the universe. There is no time, only three-dimensional space, so it can't be called the universe! The universe contains three elements: time and space matter are indispensable!

Philosophers in ancient China used to say that the universe is up and down, and the ancient and the modern are dominant.

The upper and lower three-dimensional space is the universe, and the eternal time is the universe. A four-dimensional space with three-dimensional space and time is called the universe. It is conceivable that there is no matter outside the universe (because where there is matter, it is a part of the universe), and where there is no matter, there is no time (time exists because of the change of matter, which is explained in philosophy). So the universe has an end!

Now that the first problem has been solved, the second problem will be easy to handle. Theoretically, a substance can be infinite, just as a number can be infinite, but are there infinite atoms to combine an infinite substance? Obviously, atoms are not theoretical things like mathematics, and they can be infinite. From the beginning of the universe to the present, atoms are all matter. Although the number of atoms is increasing, it will increase anyway. Even in another n billion years, the number of atoms in the universe is limited, and limited atoms cannot be combined into infinite matter!

The combination of substances depends on the mutual attraction between substances. As long as the attraction between substances is large enough, they can be combined into an infinite number of substances, but there is also the problem of intermolecular gaps. If the molecular gravity is large enough, matter can be compressed into a point. On the other hand, if the gap between substances is large (to a certain extent, if the attraction between molecules exceeds a certain level, it will not attract each other and cause the separation of substances), it can be large, but it can never be infinite!

Where is the "end" of the universe? Since ancient times, people have been exploring. What people know is that the universe is composed of various celestial bodies, so how to measure the distance between celestial bodies naturally becomes a means to find the "end point".

Let's take a look first. How is the distance between celestial bodies measured?

When people observe a celestial body, they find that its spectral line is not at the standard wavelength. The wavelengths of all spectral lines are lengthened, indicating that the spectral lines move to the red end. This phenomenon is called spectral line redshift, which is caused by Doppler effect. When celestial bodies or observers move, the wavelengths of light and electric waves emitted by celestial bodies will change. When the celestial body moves towards the observer, the distance will be shortened and the wavelength will be shortened; When the celestial body deviates from the observer's motion and the distance continues to lengthen, the phenomenon of wavelength lengthening will be observed. The red shift of celestial spectral lines indicates that celestial bodies are moving away from us.

If "z" is used to represent the degree of redshift, the wavelength of light and electric waves emitted by celestial bodies with "z" redshift will become 1+Z times of the original wavelength when observed on the earth. For example, in a celestial body with a red shift of 4, hydrogen atoms emit ultraviolet light with a wavelength of 12 16 angstrom, while the red light with a wavelength of 6080 angstrom observed on the earth becomes visible light that can be observed by naked eyes. According to the Doppler effect, the greater the deviation speed, the greater the red shift. So we can calculate the speed of celestial bodies leaving us according to the red shift.

If the light emitted by celestial bodies is analyzed by spectrum, the specific red shift wavelength emitted by hydrogen, oxygen, carbon and other atoms can be detected. From this, the degree of red shift of these specific wavelengths can be calculated. According to the Doppler effect, the redshift of celestial bodies means that the universe is expanding, and the gravitational field equation of general relativity also has the solution of "expanding cosmology". Thus, the "theory of cosmic expansion" was formed. Others put forward other forms of cosmology, such as "steady-state cosmology". These cosmologies also advocate the expansion of the universe. The distance between celestial bodies and the earth sphere is obtained by the method of converting red shift into distance, which varies with the universe model adopted.

The model of the universe determines that the current expansion speed of the universe expressed by Hubble constant and the expansion deceleration rate of the universe expressed by "deceleration parameters" should also be obtained from observations.

According to the rapidly expanding universe model after the birth of the universe, it is assumed that the Hubble constant is 50km/s/ 1 million parsec (the difference between 1 s is about 3.26 light years) and the "deceleration parameter" is 0.5. It can be calculated that the age of the universe is 65.438+0.3 billion years, and the distance from the earth to the "end" of the universe should theoretically be 65.438+0.3 billion light years.

Experts believe that the known "end" of the universe is a celestial body-[4g41.17] that is1700 million light years away from the earth. It was in August of 1988 that Chambers of Johns Hopkins University and George Murray of Space Telescope Science Institute discovered this number. Subsequently, the National Astronomical Observatory on Mount Kitt in the United States took photos and observed the spectrum.

The emission spectra of hydrogen atom and carbon atom show that [4g4 1. 17] is a celestial body with a red shift of 3.8. According to the previous model, this celestial body is11700 million light years away from the earth. It was previously confirmed that the celestial body numbered [0902+34] is closest to the Earth, and its distance from the Earth is11500 million light years.

Light and radio waves travel at a speed of 300,000 kilometers per second. [4g4 1. 17] It took11700 million light-years for the emitted light and electric waves to reach the earth. So what we see is the majestic figure of [4g41.1.700 million years ago, so let's not only observe it.

Before the birth of the universe, there was no time, no space, no matter and no energy. About 654.38+05 billion years ago, in this empty "nothingness", an infinitesimal point exploded. From this moment on, matter and energy are produced, which is the big bang created by the universe.

The new universe is hot and dense. With the rapid expansion of the universe, its temperature drops rapidly. After the first 1 second, the temperature of the universe drops to about 1000 billion degrees. At this time, the universe is a pot of basic particle soup formed by protons, neutrons and electrons. As the soup continues to get cold, nuclear reactions begin to occur, producing various elements. The particles of these substances attract and fuse with each other, forming larger and larger clumps, gradually evolving into galaxies, stars and planets, and life phenomena have also appeared on individual celestial bodies. Then, human beings who can understand the universe were finally born.

This picture of the Big Bang is the most possible explanation about the origin of the universe at present, and it is called the "Big Bang Model". The Big Bang Theory was born in the 1920s, supplemented and developed in the 1940s, but it has been unknown. It was not until the 1950s that people began to pay extensive attention to this theory, but they were just amused and unconvinced. People prefer to think that the universe is stable and eternal.

However, more and more evidence shows that the big bang model is powerful in science, at least there is no better theory than it now. We must believe that the universe begins and ends. It comes from "nothing" and may eventually return to "nothing".

Eternal silence

For most of human history, the problem of creation has always been left to God to solve. Where did the universe originate? Where is the destination? How did life come into being? How did humans come into being? Many religions can give systematic answers to these questions. As for where God comes from, this kind of question should not be asked. It was only in recent centuries that people began to learn to put God aside and think about the origin of the world from a perspective other than religion. So there is a major principle problem to be solved: does the universe exist forever or has a beginning?

This problem has long puzzled scientists, philosophers and theologians, not to mention ordinary people. Different versions of religions and myths believe that the world has a beginning and set the time of creation in the not too distant past-usually thousands of years ago. This is certainly not credible, because subsequent geological and astronomical observations show that the age of the earth and other celestial bodies is hundreds of millions of years old. It is hard to imagine such a long time, so many people tend to think that the universe has always existed and has no origin in time, that is, the age of the universe is infinite. The concept of infinity is confusing: since infinite time has passed, what is our "present"? And if the universe has a beginning, how did it suddenly emerge from nothing? Do we really need a God who created the world?

It is difficult to fully understand these with the knowledge gained in the short life of mankind. However, we can seek some scientific evidence to get as close to the truth as possible. One of the basic assumptions of the Big Bang model is that the age of the universe is finite. The convincing direct reason for this statement comes from the second law of thermodynamics, which is the most basic law in physics. The saddest and most desperate law in the history of science seems to have stipulated the fate of the universe.