Is the universe expanding indefinitely, will the universe expand indefinitely?

There are three possible models of cosmic development, which are not very different in the early stages of cosmic development, and have different results in the later stages of evolution. At present, the universe is in a stage of expansion, and it is not yet possible to determine what kind of system the universe is.

Open Universe: The Universe is Big**.

After expansion, the expansion force of expansion is much greater than the gravitational force.

The universe will expand endlessly. The continuous expansion of the universe leads to an infinite increase in the entropy of disorder, the universe develops to the most chaotic state, all celestial bodies decompose, and only photons and leptons remain in the universe.

Enter a heat death state.

Balancing the Universe: The expansion force of the expansion is about the same as the gravitational force, so the expansion will be slower and slower, and finally expand at an extremely slow rate.

Closing the universe: The universe expands after it is large, and the expansion force of expansion cannot compete with the gravitational force, so when it reaches a certain level, the expansion tends to stop, and thus begins to shrink in the opposite direction of expansion. Finally, the universe collapsed into a singularity after the Great Squeeze.

The universe will not expand indefinitely, and when the universe expands enough to be too large to support its own gravity, the universe begins to collapse and return to the singularity, and if the big ** occurs again, a new universe will be formed.

At present, the universe is expanding at an accelerated pace, and whether the universe will expand forever in the future depends mainly on the increase or decrease of dark energy in the future, and if the dark energy continues to increase, the universe will expand forever, but the current research on dark energy is not enough, and there is no unified view of what will happen in the future.

According to Hubble observations and the redshift theory, the universe is expanding all the time, and all the planets are moving away from each other, and the farther away they are, the faster their relative motion becomes.

What forces can push the universe to expand? According to the hypothesis that the universe is large, scientists speculate that a long, long time ago, the universe was very small, like an egg, and cosmologists figuratively called it the cosmic egg. This cosmic egg is very hot, with a temperature of about 1 trillion degrees, so it is also called the "primordial fireball".

Suddenly, at a certain moment, this primordial fireball **, and the matter dispersed, and the universe began to expand from there, which has continued until now. Scientists have found that while the universe is expanding, it is also cooling down, and the temperature of the universe has dropped to -210. Of course, this does not mean that this temperature is everywhere in the universe, for example, the temperature on stars is very high, and some even reach tens of thousands of degrees.

But in the empty universe, these stars are like bonfires in a cold night, and no matter how high the temperature is, it can't change the cold world around them. Like a campfire, no matter how high the temperature is, it can't change the cold world around you. Scientists have discovered that although the universe has been expanding, the rate of expansion is gradually slowing down because of the gravitational pull between the matter in the universe.

This gravitational pull pulls back the matter that is detached from each other. But what is difficult to estimate is the magnitude of the gravitational force of the grip. If the gravitational pull is not too strong, then the expansion rate is slowing down, but it will never become zero, and the universe will expand indefinitely.

If the gravitational pull is strong, then the speed of the expansion of the universe will gradually decrease to zero, and at that time, the expansion of the universe will stop and begin to contract, shrinking smaller and smaller. Some astronomers believe that the density of matter in the universe is very small, so the gravitational attraction is also weak, and the universe will expand indefinitely. Some scientists take the opposite view, arguing that the gravitational pull in the universe is much greater than we know, enough for the universe to stop expanding and begin to contract.

Judging from the current most mainstream big ** theory, the universe has boundaries and no boundaries, so big that you can't see the edges. Cosmic Oak is still very young now, and he can't estimate the time of the end. According to the theory of the Great Tear, the universe will continue to expand, and the galaxies will be farther and farther apart.

If it is cyclical, the universe will stop expanding and begin to contract after a long, long time, and will eventually contract back again.

The universe expands because dark energy works all the time. Gravitation is not the culprit of the expansion of the universe, and even, it has been grinding with a duanzao, fighting against this expanding force. As we all know, the universe is vast and eternal, and it is said that it is now more than 10 billion years old.

Human beings are just passing bys who have been born on Earth for tens of thousands of years, and we are nothing compared to the universe. Today, the "grand theory of the universe" has become the mainstream interpretation of the origin of the universe in the academic community; However, it also unravels many of the cruel truths that exist in the universe. For example, the universe will one day embark on the path of destruction

That's right, 13 billion years ago, the big ** of the Schwarzschild singularity gave rise to the universe; However, the expansive effect of the singularity on space-time has not stopped to this day. The universe is still expanding at a speed more than ten times the speed of light; One day, maybe all the galaxies and star clusters in the universe will be torn apart because of this. What exactly is the culprit that is causing the expansion of the universe:

In the scientific community, this "repulsion" is called dark energy. Dark energy, like dark matter, cannot be seen or touched, but the grip is everywhere and everywhere, even near the earth's atmosphere, it is full of this "dark energy". Some people feel that it is gravity that causes the universe to expand outward; As everyone knows, this is a big black pot for it.

Why? In fact, gravitational force has been fighting against the "repulsion" brought by dark energy and maintaining the stability of the cosmic order. To this day, NASA data indicates that the Moon is fleeing the Earth about eight centimeters a year; If it weren't for the influence of gravity, it might have run out of bounds in a day.

However, the effect of gravity is not enough to completely counteract the effects of dark energy. That is to say, the expansion of the universe is endless; We must find a new universe before the day of destruction comes.

Three-dimensional space is length, width, and height, and time is four-dimensional space.

The expansion of the universe generally does not occur in three-dimensional space, but in four-dimensional space, which includes not only ordinary three-dimensional space (length, width, and height), but also the fourth dimension of space, time. It is very difficult to describe the expansion of four-dimensional space, but we may be able to explain it by inferring the expansion of the balloon.

The universe is not only expanding, but it is expanding at an accelerated rate. The current explanation is that dark energy acts more than gravitational pull, causing the universe to expand.

The mainstream view in modern cosmology is that the origin of the universe originated from a large **, which evolved from a state of extremely dense and extremely high temperature in the past, and reached a state through continuous expansion, which is called the grand theory of the universe or the theory of the singularity.