Human beings are the only intelligent life on earth. Starting from the primitive age when they were drinking blood from hairs, humans have had infinite reveries about the vast starry sky. It’s just that in the hearts of ancient humans, there is more fear of the stars, especially when they see meteorites falling to the ground, they are even more afraid of fear.
Due to the lack of scientific knowledge, ancient humans did not understand the starry sky outside the earth at all, and did not know what kind of world it was, and many beautiful myths and legends were born from this.
With the continuous development of mankind, from the primitive age into the feudal age, and finally into the technological age. Although mankind has entered the age of science and technology in only a short period of more than 200 years, the achievements we have achieved are amazing. With the help of technology, people’s quality of life is getting higher and higher, and at the same time we have stepped out of the earth and began to explore the universe.
Only when we truly walk out of the earth can we know how vast the universe is and how small the earth is. Standing in space to observe the universe is completely different from standing on the earth to observe the universe. The starry sky outside the earth is more mysterious and fascinating for mankind. After entering the technological age, we also know that the twinkling stars in the night sky are basically stars. So many people have a question: how many galaxies and how many stars are there in the universe ?
To understand how many stars and galaxies there are in the universe, we must first understand how big the universe is. In the early days of exploring the universe, our observation technology was relatively low-level, and the range that we could see was very limited. At that time, scientists believed that the Milky Way was the entire universe. In the Milky Way, the number of stars did not seem to be many.
However, with the continuous advancement of science and technology, observation capabilities have also been greatly improved. With more advanced astronomical telescopes, we can see the outer starry sky through the Milky Way. At this time, we understand that there is a vast and vast outside of the Milky Way. After all, the universe is much larger than we thought.
With the proposal of the Big Bang theory, scientists have discovered that the age of the universe is 13.8 billion years old, and the observable universe of mankind currently reaches 93 billion light-years. The calculation of this range is actually based on the Big Bang theory of the universe and the speed of photons, and based on observations, scientists have also issued an astonishing fact that the universe has been accelerating expansion.
If the expansion speed of the universe exceeds the speed of light, then the photon cannot reach the observable range. If our astronomical telescope cannot observe the photon, then it cannot know which position is there, so there is a definition of the observable range. Beyond the observable range, there is even more vast cosmic space, but we can’t observe it at all there. What we can see is only a dark and mysterious space.
So, when we discuss how many stars and galaxies there are in the universe, just based on the observable range of 93 billion, how many large galaxies like the Milky Way are there in this range? How many stars are there like the sun?
Theoretically speaking, as long as we are given a very advanced telescope with a long enough observation time, we can scan the entire cosmic starry sky once, and then we can count all the star coefficients. Of course, this is just a theory, and in reality we cannot do it at all. Our observation of the starry sky can only be carried out within a very limited range.
The human eye’s ability to observe with the naked eye is very limited. When we stand in space and watch the universe, most of the space we see is dark. So in the dark starry sky that we see with the naked eye, is there nothing left? In order to solve this mystery, scientists used high-precision astronomical telescopes to conduct multiple observation experiments.
In 1995, scientists pointed the Hubble Space Telescope at a star area that seemed to have nothing, and began a 10-day observation. This area only occupies a 24 millionth of the entire starry sky, and it is completely dark in human observation with nothing. However, through ten days of observation, the data obtained surprised people. It turns out that this inconspicuous area has hidden as many as 4000 galaxies.
In 2003, the scientists pointed the Zhibo telescope at the sky furnace constellation. This area was smaller than the area observed last time, accounting for only one 26 millionth of the sky. After several days of observation and sorting, nearly 10,000 galaxies of different colors and sizes appeared in one photo.
Hubble’s last deep-space observation was in 2012. The scope of this observation was much smaller than the previous two, accounting for only one-third of the entire starry sky. It is this area the size of a needle eye. After 23 days of long observation, a stunning photo was also obtained, in which more than 5,500 galaxies appeared.
Through three observations, we can see that there are a large number of galaxies hidden in a dark starry sky region in our naked eyes, and these galaxies are basically large galaxies similar to the Milky Way. There are hundreds of billions of stars in every “Milky Way”, and the number of planets is even harder to count.
So how many galaxies are there in the current observable range? At the beginning, scientists estimated that it was 176 billion. Later, scientists at the University of Nottingham in the United Kingdom designed a virtual universe in a computer, which was based on the Big Bang theory and added various physical parameters and mathematical models.
Through the calculation of this virtual universe, there are at least 2 trillion galaxies within the observable range of 93 billion.
These galaxies are just a current number. Since the universe was born, galaxies have been in constant motion, swallowing and merging are also progressing, so the number and density of star coefficients in the early stage of the universe are much greater than it is now. Of course, the amount of star coefficients we currently observe is only a tiny part of the entire starry sky. In fact, due to the obstruction of cosmic dust, many stars are very dim. In addition to the distance factor, we cannot observe them.
Therefore, the astronomical telescope continuously observes a small area, and the amount of star coefficients obtained is only part, not all. With the continuous advancement of human science and technology, we will be able to observe more galaxies after more powerful starry sky telescopes are available in the future. I believe that as long as human beings continue to work hard, one day, we can observe all galaxies in the entire universe, and even the starry sky outside the observable universe. We can also observe them in other ways.
It’s just that, as our observing capabilities continue to improve, we have more and more understanding of the universe, and we feel more and more insignificant. Although our observation range is very far and wide, there is still a long way to go before we go to the field for exploration. After all, we have not even gone out of a small solar system.