In the past, due to the limitations of the development of the times, the ancients could only see the land under their feet. When they looked up, they could only see the night sky mottled with stars, and when they lowered their heads, they could only see the flat ground. But I don’t know that the outer sky is a vast and boundless universe
Of course, the ancients who knew how to think also imagined the world in which they lived, but the big environment at that time was all idealistic thinking, full of gods, Buddhas and ghosts. They escaped smoothly until under the dual oppression of feudal rule and religious forces, people in the western world finally rose up to resist, lifted the curtain of ignorant traditional thinking, and opened the curtain for the development of advanced thinking. Since then, with the passage of time, scientific ideas and technologies have been continuously improved and breakthroughs, people have also changed from the early “geocentric theory” to “heliocentric theory”, and gradually discovered the Milky Way.
From the geocentric to the heliocentric, it was a great progress in thinking until the birth of the Hooke Telescope in 1919. People were shocked to realize that the Milky Way is not the largest world. The universe is constantly expanding, and there is no edge and no so-called “center”.
Of course, to know the answer to this question, we first need to look at the birth of the universe
, the most widely circulated and widely recognized origin of the universe is the Big Bang cosmology, according to which the universe started out as an infinitely small, infinitely hot and infinitely heavy: singularity:
This “singularity” is actually just a concept. In mathematics, it refers to an undefined point.
Infinitely small, but does not exist in the world, and in the big bang cosmology, this singularity is an indescribable, but real point that is based on such a magical “singularity”, the universe happened. In a big bang, all matter, energy, time and space were born, and various changes took place over time. Finally, about 13.7 billion years later, that is, today, the colorful, mysterious and complex cosmic world formed today. .
At the same time, after the universe exploded, it continued to expand outward. For example, in 1929, astronomer Hubble discovered that the galaxies in the universe are all in
The phenomenon of moving away from each other, which shows that the galaxies in the universe are also affected by the expansion of the universe
Galaxies are moving away from each other and this expansion is faster than the speed of light. Humans currently observe the universe to the greatest extent only by light and electromagnetic waves, and they are both the speed of light and have not broken through the limit of the speed of light. This also means that if we do not develop research and development Faster and more powerful than the speed of light, then we will always be confined in place, unable to transmit or even receive any information.
On this basis, it is difficult for humans to observe the boundary of the universe, because even if there is a boundary, it will be farther and farther away from us, we will always pursue, but never get close.
The universe is “bounded and unbounded”
Einstein has his own views on the boundaries of the universe. He believes that the universe is “bounded and unbounded”. The universe we live in is actually a multi-dimensional universe. Maybe in the eyes of us three-dimensional creatures, the universe may have boundaries, but multi-dimensional creatures In the eyes of the universe, the scope of the universe is still far away.
The concept of the multidimensional universe is like a Möbius strip. It is a strip of paper made by rotating one side of a piece of paper 180 degrees and connecting the two sides, but its magic is that the Möbius strip is only There is a face, it has no so-called front and back, if you put an ant on it, then the ant can go anywhere on the Mobius strip without turning over the paper tape.
The Mobius strip with only one side can be changed to a more convenient way to understand. We can use drawing on paper as an example. Usually, when a piece of paper is not turned over, we can only smear on one side. , the other side cannot be “scribbled” by us. However, if this is a Mobius strip, then we don’t need to turn it over and draw a line that never loosens on it with a pen, then it can be drawn everywhere by us. On this basis, we extend to the Klein bottle, which is a four-dimensional object formed by two Möbius strips along only one side. Just like the Möbius strip, it is also only composed of It is composed of a curved surface, but from the perspective of the three-dimensional world, we find that the Klein bottle must have intersecting parts. But the Klein bottle doesn’t actually have an intersection. It’s more accurate to say that it doesn’t intersect in four-dimensional space.
From here, we can find that the Klein bottle itself has not changed, but it has two completely different appearances in the three-dimensional world and the four-dimensional world, and human beings can never restore the Klein bottle in the real world, even no matter what No clever genius scientist can imagine what a complete Klein bottle looks like.
In the same way, is the universe in our eyes the most complete universe? We don’t know the answer, but perhaps, in the eyes of people in the four-dimensional world, the universe is like a Klein bottle, belonging to a space-time with only one infinite cycle. will expand infinitely, but never reach the limit
This may be why Einstein said that the universe is “bounded and unbounded”.
magnify and magnify the universe
Although we already have a certain understanding of the universe, in fact, the level of human science and technology is still nothing. A large number of advanced astronomical equipment were actually invented in modern times, and it may be about a hundred years from now. It can be seen that , our modern astronomical technology is actually relatively weak, and therefore human’s cognition of the universe can only be said to be superficial.
The universe is endless, but at the current level of human technology, the scope of the universe we can observe is limited to a “circle” with a diameter of 93 billion light-years, and it is still impossible to break through and discover more distant universes. And if this observable cosmic space is enlarged and enlarged, what will we be able to see.
According to the distant interstellar images 1 billion light-years away from astronomical equipment, we can find that this is a dark cosmic background with galaxies the size of fine sand grains on the beach. But at such a large scale, the universe doesn’t actually seem to be “crowded”, and it can even be said to be a little starry sky.
We choose the middle piece of galaxies with densely distributed “sand” to pull in. After zooming in by 100 million light-years, we can see that the universe is actually relatively empty, but the “sand” in the middle is brighter and sparser. After zooming in for another 10 million light-years, these “grains of sand” that were originally next to each other are far apart, or they can no longer be called “grains of sand”, but “sesame seeds”, which are even bigger than before. Sharper, looks like a white point of light, but it’s actually a
galaxy.
When we zoom in by another 100 million light-years, we can see a galactic disk slightly larger than a peanut, with countless stars orbiting on it, forming a dazzling and beautiful galaxy.
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