The universe is not eternal, which is a very unacceptable statement, because the end and death are the most terrifying.

The universe is not eternal. This is a very unacceptable statement, because the end and death are the most terrifying.

This is just like life will eventually die. People are unable to stop it but have to admit this fact, so they fantasize about reincarnation to comfort themselves. Although there is no evidence for this, if anyone dares to question it, there will definitely be opposition. , because questioning reincarnation is equivalent to killing people's hope for "eternal life". Similarly, if the universe is not eternal, then reincarnation has no meaning, so this is bound to be an unacceptable statement. In the era of Newton , people believed that the universe was static and eternal. However, with the introduction of general relativity , the problem became a little different. People began to realize that the universe was not static, let alone eternal.

The universe is not eternal. Not only is this difficult for ordinary people to accept, but even Einstein, the proposer of the general theory of relativity, does not want to believe it.

For a long time, Einstein has tried to modify his formulas and tried to add a so-called cosmological constant to his equations. The only purpose of doing so is to hope that the formula of general relativity will eventually The solution could be consistent with the static and eternal universe of Newton's era, but Einstein failed. In the end, he accepted the conclusion drawn by many scientists based on the general theory of relativity: the universe is expanding, and the universe is not static, let alone eternal. The universe has a beginning, and this beginning is the Big Bang hypothesis. Although it is a hypothesis, it is by far the most well-documented and most recognized theory of the origin of the universe. All current research on the universe is basically based on this foundation. above.

The Big Bang created the universe, and then the universe began to expand. 13.8 billion years have passed, and the expansion of the universe has never stopped.

The expansion of the universe is the expansion of space itself. It occurs at every point in the universe. We can imagine the universe as a balloon, and put many small dots at different distances on it, and then we start to inflate the balloon. The distance between these points begins to gradually become farther and farther, which is the expansion of space itself. The universe is expanding. Will it continue to expand? What will be its final outcome? The final outcome of the universe is closely related to the shape of the universe. It is now generally believed that the universe may have three different shapes. The first view is that the universe is closed, which is also a view that is easier for most people to accept.

The closed universe is like a sphere, limited but unbounded.

Since the universe is closed, the expansion of the universe will gradually weaken due to the gravitational effect of the internal matter. Eventually, the expansion will stop, and the universe will begin to change from expansion to contraction under the action of gravity. This contraction process will gradually accelerate, and the entire universe will It collapses again into a point with infinite density and infinitely small volume, which is the singular point . After a long, long time, the balance inside this singularity will be broken again due to some unknown factors, so the big bang occurs and a new universe is born. The second view is that the universe is not closed, but flat. The flat universe is like a plane. The constant expansion makes the plane become larger and larger. However, the expansion will not continue endlessly, and its speed will gradually weaken.

As the expansion rate weakens, the flat universe will eventually stop, but before that, everything in the universe will return to equilibrium.

We know that there are various forms of matter in the universe, but all matter is essentially composed of elementary particles. Over time, all stars in the universe will eventually run out of fuel, they will collapse, and then cool. Of course, massive stars will collapse into black holes, but black holes will also gradually evaporate due to Hawking radiation. Although This process is extremely slow, but the universe has plenty of time. Slowly, the universe became colder and colder, and the temperature finally reached absolute zero.At the same time, due to the continuous expansion, the matter in the universe gradually moves away, and eventually all matter is torn into the form of elementary particles, and is evenly distributed under the action of space expansion.

The universe finally reached a state of absolute equilibrium. The entropy in the universe increased to the maximum. This is heat death.

The third view is that the universe is completely open. The open universe is the opposite of the closed universe. It presents a state of negative curvature. In this state, the expansion of the universe will not stop, but will It will continue forever, so its ending is the same as the flat universe, heading towards heat death. Different shapes of universes have different endings, but whether it is heat death or contraction, although they seem to be completely opposite, they all point to the same end, that is, death. This may seem hard to accept, but it is the closest to the truth. None of the things we have seen so far can be eternal, so being obsessed with eternity will only increase troubles. When you begin to accept the fact that "death represents the end of everything," you will find that your life will become different, and every minute and second will be wonderful. This feeling is a bit like a person who becomes fearless in life after learning that he has a terminal illness.