When human beings walked out of the earth with the help of science and technology, we discovered that the world outside the earth is so vast and wonderful. When human beings really see the vast universe, their enthusiasm for exploring the universe is constantly rising.
Human civilization relies on infinite curiosity about the unknown to be able to enter the era of science and technology in a short period of time and achieve rapid leaps. Before human beings walked out of the earth, we were exploring and studying the secrets of the earth, and we could only look at the starry sky.
However, after we have truly stepped out of the earth, the focus of scientists’ exploration has also been on the vast universe. There are too many mysteries in the universe waiting for us to solve, and among the many mysteries, it is the earliest scientists to explore the origin of the universe. Through a large number of universe observation and research, scientists put forward the theory of the Big Bang.
Scientists believe that our universe originated from a singularity explosion 13.8 billion years ago. This singularity is something hot, dense, full of matter particles and high-energy radiation. Its volume is infinitely small, but its mass is infinitely large. Although the Big Bang theory is a conjecture put forward by scientists, in subsequent continuous observational research and exploration, scientists have discovered more and more evidences that can prove the correctness of the Big Bang theory.
Now, the big bang theory has basically been universally recognized by the scientific community, and under the big bang theory, another cosmic phenomenon has attracted the attention of scientists, that is, the expansion theory. The original universe was very, very small. After the Big Bang, the universe was born and began to expand rapidly.
The temperature of the universe also slowly cooled down as the universe continued to expand, and then stars, planets, galaxies and other celestial bodies and materials continued to form. The expansion of the universe is not difficult to observe. Through astronomical telescopes, we can easily observe that galaxies in the depths of the universe are constantly moving away from us. set up.
The constant expansion of the universe also tells us such a truth: that is, there may be space outside the universe, so what will be outside the universe? I believe many friends know that if a balloon wants to expand and grow bigger, an important prerequisite is that there must be enough space outside the balloon to expand. If the balloon is fixed in a limited space, then the balloon cannot expand indefinitely, at most it can only expand to the size of the fixed space.
The universe has been 13.8 billion years since its birth, and its expansion has been going on all the time. If there is no space outside the universe, how can it expand? Therefore, more and more scientists believe that there is space outside the universe, but what is happening outside the universe is still unclear. Some scientists speculate that the universe may be diverse.
Outside of our universe is a vaster mother universe, in which there are countless kinds of universes, and our universe is just one of them. The universe is expanding rapidly, so there is an observable universe and an unobservable universe. So what is an observable universe?
I believe many friends know that the observable universe of mankind is about 92 billion light-years away. How did this range come from? In fact, it is defined by the speed of light. We all know that the speed of light is the fastest speed in the universe. Only photon plasma can reach it. Mass objects can only approach the speed of light infinitely. This is the answer that the theory of relativity tells us.
The universe did not exist before the Big Bang, without any matter, without any radiation. It wasn’t until the big bang occurred at the singularity 13.8 billion years ago that vacuum energy was produced, which pulled the universe to expand continuously. According to the research of scientists, at the moment of the Big Bang, the expansion speed of the universe far surpassed the speed of light, so a very large cosmic space was formed in a short period of time.
The universe has been expanding until it was born, or into the future, and has never stopped, and the expansion speed of the universe far exceeds the speed of light. After the universe went through the reheating phase, the big bang began and experienced a series of high-energy collisions between particles and particles, which also created all the elementary particles we know or do not know today.
380,000 years after the Big Bang, as the universe expanded and cooled, neutral atoms were formed. There are no stars, galaxies, etc. at this time. These luminous material structures were formed between 50 million and 100 million years after the birth of the universe. Therefore, when the star-forming photons rush towards us, the universe has already Expansion to no margin.
Light from galaxies closer to us can reach the earth in a short time, while galaxies farther from us take longer. However, the speed of light is limited. If the universe is not expanding, photons no matter how far away from us will be able to reach the earth one day. However, the universe is constantly expanding, and due to the existence of dark energy, the universe began to expand at an accelerated rate 4.5 billion years after its birth, and this expansion speed exceeded the speed of light.
This means that the light of those galaxies has not reached the earth’s galaxies and will never reach the earth. We will be able to see those that have already reached, but the farthest of them has expanded to near 46 billion light-years. This is our observable universe. The galaxies whose light has never reached the earth are outside the observable universe.
Whether it is the observable universe or the unobservable universe, it belongs to our universe, and there may be even more vast space outside this universe, otherwise the expansion of the universe should have stopped long ago. If there is space outside the universe, it must also be an extraordinary space. Scientists have more speculations about the multiverse.
Before mankind entered the age of science and technology, the ancients also believed that our earth is the entire universe, a vast space. But when we entered the age of science and technology and stepped out of the earth, we only realized that the space outside the earth is more vast and mysterious, and our earth is just one of countless planets.
In the same way, human beings are still very weak in science and technology, and they have not been able to observe the edge of the universe, let alone get out of the universe. If human technology reaches a higher level in the future, we can jump through space at will and reach the edge of the universe. Then it is possible to truly see the world outside the universe, just like human beings are standing in an atmosphere of tens of thousands of meters. Although they are still on the earth, we can already see space.
When human beings have the ability to reach the edge of the universe, the tip of the iceberg outside the universe may be able to appear before our eyes. When human technology develops to a higher level, it may be possible to get out of this universe and go to the world outside the universe. explore. At that time, we might also sigh with emotion: It turns out that the universe in which humans live is nothing but a dust in the mother universe.