Whenever people look up at the stars at a 45-degree angle, excellent vision allows people to see about 6,000 stars. Among them, there is a celestial body called Cassiopeia V762, which is the farthest object that can be seen by the naked eye, about 16,300 light-years away from the earth, which translates to 1.5 billion kilometers, and if you run there at a speed of 120 kilometers per hour, it will take about 140 billion years, which can be said to be a rather terrifying distance.
But you know what? This distance is nothing in the universe at all, and it is negligible relative to the universe we are in. So the question is, how big is the universe? How small are human beings?
Dull blue dots
Before we get into this, let's start with a photo. If you want to ask what is the farthest flying machine from humans?
So now the answer must be: Voyager One, now 23.3 billion kilometers away from Earth, is the furthest man-made object from Earth. It was launched on September 5, 1977, with the main mission of exploring Jupiter and Saturn, and then flying as far as possible towards the center of the Milky Way.
It is said that after completing its main mission, on February 14, 1994, the ground command center issued instructions to it to take pictures of the planets in the inner solar system, but at that time, because Mercury was too close to the sun to find it, and Mars was too small to shoot, the remaining planets were photographed by Voyager One, and scientists eventually drew a family portrait of the solar system.
Among the family portraits of the solar system, there is a particularly striking picture, which has a 0.12 pixel-sized highlight, and on this highlight, it is inhabited by 7 billion people and countless animals and plants, yes, it is the earth. And this picture later had an interesting name, the famous astronomer Carl Sagan called it: dim blue dot.
But we need to know that Voyager One has not flown out of the solar system until now, it will take at least tens of thousands of years to fly out of the solar system, and the picture it took 28 years ago has made us almost invisible. It can be seen that we are not only small relative to the universe, but only the solar system, human beings have been small enough to dust.
Vast universe
However, the solar system is actually not very large, and we all know that the solar system is in the Milky Way. The Milky Way is 100,000 to 180,000 light-years in diameter, with about 150 billion to 400 billion stars like the Sun. In other words, the solar system is actually a small dust existence in the Milky Way.
So the Milky Way is big, right?
In fact, there are more celestial bodies in the universe that are larger than the bank system. Larger than galaxies are called clusters of galaxies or clusters of galaxies. The group of galaxies we are in is called the Local Group of Galaxies, and it is 10 million light-years in diameter. There are dozens of galaxies like the Milky Way in this group.
Larger than the group of galaxies are the supergalactic groups or superclusters. The Local Group is located in the Virgo Supercluster, which is just an ordinary member of the Virgo Supercluster. According to scientists' estimates, the Virgo supercluster has a diameter of 110 million light-years, contains at least 100 galaxy clusters and galaxy groups, and the number of galaxies is about 47,000.
That Virgo supercluster is finally big enough, right?
The answer is obviously not the same, the Virgo supercluster is in the Raniakea supercluster. The Raniakea Supercluster is 520 million light-years in diameter and has at least 100,000 galaxies. The Ranyakea Supercluster is in the Pisces-Cetus Supercluster complex, which is about 1 billion light-years long and 150 million light-years wide. So, did you find it? It's like a nesting doll, which can be put on layer by layer.
Unfortunately, for humans, however, we don't always know what it is to go down. This is because the universe was born 13.8 billion years ago in a big bang, after which the universe began to expand, and because the fastest speed of transmission with matter, information, and energy in the universe is the speed of light.
Human observation relies on electromagnetic waves, so the range of human observation is limited, counting the expansion effect of the universe, the limit range that human beings can observe is a spherical space with a diameter of 93 billion light years, which is also known as: observable universe.
The Virgo Supercluster, the Raniakea Supercluster, and even the Pisces-Cetus Supercluster complex are only a small part of the observable universe, with at least 2 trillion galaxies in the observable universe.
And the observable universe? It's really just a small part of the universe, not the whole universe. That is, from a spatial point of view, due to the limitation of the "speed of light", we are locked in the observable universe and can never know how big the universe really is. Some scientists believe that the universe is likely to be infinitely large.
But that's not all. From the perspective of the material-energy dimension, human beings are also very sad. This is because there is still dark matter and dark energy in the universe, which account for more than 95% of the total universe, and the known matter accounts for less than 5%, which means that they are the real protagonists in the universe, and we are a minority and cannot see them. Therefore, at the energy-matter level, human beings are also small.
We can also look at the "time" dimension, the universe was born 13.8 billion years ago, and the first civilization of mankind was born in the plains of Mesopotamia in 3500 BC. If the 13.8 billion-year history of the universe is considered to be a year, then human civilization has less than a second.
Therefore, whether in terms of space, time, or energy-matter dimensions, human beings are negligible relative to the universe.