How big is the universe?

The universe is so large that it is at least 93 billion light-years in diameter. However, it is not yet known whether the universe as we recognize it is the entire universe. We all know that in the past 100 years, human society has made countless brilliant achievements and changed our way of life through modern science, which is a magic weapon to transform nature and understand the world.

However, the universe is so big and vast that there are still many "unsolved mysteries" waiting for us to explore on the road ahead of human progress. Moreover, compared to the vast universe, the earth is not as good as even a speck of dust. The diameter of the solar system is only three to four light-years.

To date, the farthest and fastest vehicle we have developed, Voyager 1, has only passed through the Kuiper belt, and it will take at least 8,000 or even tens of thousands of years to really fly out of the solar system, which is already an astronomical amount; And what is the diameter of the universe?

Nine hundred and thirty billion light years! Just imagine, that's an almost immeasurable number. It will not be possible for us to explore the universe in thousands, if not tens of thousands.

In the night sky, we look up; A casual corner may be larger than the size of the Milky Way.

This "93 billion light years" was first calculated by the famous physicists Planck, Hubble and others in the last century using the model of the universe. And after the big **, the universe is still expanding at a speed not inferior to the speed of light, without interruption, and it still is today. What does this mean?

It is very likely that the existing universe has expanded to more than 100 billion light-years.

What makes people even more "scary" is that the universe we know is likely to be only a small part of the main universe. The universe in three-dimensional space is the universe that can be tolerated under the existing scientific theories of mankind;

The real universe is said to have a total of eleven dimensions and countless multiple dimensions. Think about it, how big it must be? It's simply unimaginable.

It's so big that we can't understand it, we can't detect it, we can only infer that it's still expanding, but we can't know how big it is.

We often use the term "vastness" to describe the universe, indicating that the universe is boundless and cannot see boundaries. In addition, there are many planets in the universe, including the Earth, the Moon, Mars, Venus, and so on.

The universe is so "big" that it can never be explored, and it is always expanding.

Because the universe refers to the sum of all physical space and time, the term "universe" probably came from the famous ancient Chinese philosopher Mozi (about 468-376 BC). He used "universe" to refer to the east, west, south, and north, and the space in all directions, and "Zhou" to refer to the time of the past and the present. Past, present, or future; Is it a recognized, or an unrecognized......In short, everything is everything.

From a philosophical point of view. It is believed that the universe has no beginning and no end, and that it is boundless. However, we are not going to go deep into this esoteric concept, and we will leave it to philosophers to study.

We might as well zoom out a little and talk about the universe that can be understood and observed using the science and technology available to us, which people call "our universe" or "total galaxy".

According to the latest observations, the farthest galaxy that has been observed from us is 13 billion light-years. That is, if a beam of light is emitted from the galaxy at a speed of 300,000 kilometers per second, it will take 13 billion years to reach Earth. This distance of 13 billion light-years is the extent of the universe as we know it today.

To be clear, the extent of the universe as we know it today, or size, is a spherical space centered on the Earth and radiated by a distance of 13 billion light-years. Of course, the Earth is not really the center of the universe, and the universe is not necessarily a sphere, but we can only understand this extent due to our current observation capabilities.

The current radius of the universe is about 46.5 billion light-years, with a diameter of 93 billion light-years. However, 93 billion light-years is only the diameter of the universe that we can observe, and since the universe is expanding faster than the speed of light, we cannot know how big the universe really is if we only observe the universe from Earth, which is still an unsolved mystery.

How big is the universe? Star Awareness Project