Human cognition grows, deepens and broadens with the development of time and technological progress.
In ancient times, we thought that the earth we live on is the center of the universe, the sun, moon and stars revolve around the earth; in modern times, the emergence of the heliocentric theory, with the blood and tears of scientists, broke this illusion and arrogance; modern times, we found that the sun is not the center of the universe, it is only a small star in the galaxy of the universe, and even, some scientists have proposed that the universe is not centered.
Our knowledge is constantly being refreshed, which also means that mankind's exploration of the universe is going deeper and deeper, and we are gradually unraveling the mysteries of the universe.
Now the concept of the Laniakea Supercluster has emerged, so let's take a look at it from our solar system.
Into the Solar System
After the accumulation of the 19th century and the first half of the 20th century, human space technology, developed rapidly and fruitfully. Mankind is full of curiosity and fantasy about the space they live in, and has explored it in the ancient and modern times. at the end of the 20th century, mankind explored the end of the universe and made new progress.
In 1977, NASA launched the Voyager 1 probe in Florida, which was, as the name suggests, a traveler of the universe, exploring the unknown and finding the boundaries of the universe in the middle of nowhere.
It has now traveled more than 23 billion kilometers, a number so large that we can not imagine, and the equatorial length is not more than 13,000 kilometers, and, if it can continue to fly as planned, without accidental events to destroy it, it will fly out of the solar system in the future.
Voyager 1, the pioneer of mankind, has explored the solar system on our behalf and has given us a wealth of data to understand it. However, the universe is too large to be perceived by humans, and thus it is necessary to estimate the size of the solar system with the help of observation techniques and extrapolation methods.
Voyager 1 has indeed been flying in the solar system for almost 50 years, but it is still far from flying out of the solar system. So how big is the solar system?
In the Milky Way, the Sun is just an ordinary star, a yellow dwarf, located in the cantilever of Orion, with a diameter of 1.39 million kilometers, which is not large in the galaxy.
However, the solar system is already very large for the planet we live on. The edge of the solar system is currently commonly said to be bounded by the boundary of the Sun's gravity, i.e. the extent of the Oort cloud.
The Oort cloud, as its name suggests, is a spherical cloud that envelops the entire solar system and contains many comets, material left over from the birth of the Sun.
The Sun was born from a nebular collapse 4.6 billion years ago, which accounted for 99.86% of the total mass of our solar system. The collapse also produced eight planets, hundreds of moons, countless asteroids, and interstellar material such as nebulae, and beyond the Kuiper belt, the Oort cloud.
Voyager 1 has to fly out of the Oort Nebula before it is flying out of the solar system. The radius of the Oort Nebula is about is 1 light year, according to the speed of Voyager 1, 17 km / s, which means that even without the binding effect of the Sun's gravity, it will take 19,000 years to fly out of the solar system.
Into the Galaxy
The solar system is already so big, but it is just an ordinary star in the Milky Way galaxy, which is not well known. How big is the Milky Way?
Although the sun is not the center of the galaxy, but not very remote, if there is a sports car in the universe, speed 120 km / h, need to travel non-stop 26,000 light years to reach the heart of the galaxy.
260 million light years may be a bit abstract, let's visualize it. If the per capita life span is set at 100 years, start traveling from your generation, your 23.4 billionth descendant, to travel to the heart of the galaxy.
The Milky Way is not only large in scope, but also in number of stars.
The Sun, which we thought was unique, has between 100 and 400 billion such stars in the Milky Way, although there are a number of binary and triple star systems in the Milky Way, which reduces the number of stars like the Sun somewhat, and even so, there are 30 to 120 billion of them, still a huge number.
In terms of mass, the Milky Way is also a big player.
The mass of the solar system is basically concentrated in the Sun, which is about 1.9891*10^30kg, a figure we cannot see in our daily life and can hardly imagine, but just think it is a huge thing; and when the Sun meets the Milky Way, it becomes insignificant.
The current observations and speculations show that the Milky Way is 700 billion to 2 trillion times more massive than the Sun, and that our solar system is a tiny piece of sand in front of the Milky Way.
However, there is a bigger world beyond the galaxy.
The word "Laniakea" is actually very beautiful, it comes from the Hawaiian language, meaning "endless paradise", which makes people feel beautiful and a little bit longing at first hearing. The name was suggested by a Hawaiian language professor who wanted to pay tribute to the Polynesian people who used their astronomical knowledge to navigate.
The Laniakea Supercluster spans 520 million light-years, with 300-500 galaxy clusters and about 100,000 galaxies, so it is no wonder that the Milky Way appears insignificant. The largest galaxy clusters are the Virgo, Serpens, and Centauri clusters.
The supercluster of galaxies is currently the largest structure under this concept of the universe, and its edges cannot yet be speculated or calculated. Mankind has been able to image the trajectory of galaxies in this cluster by means of radio telescopes.
The existence of the Laniakea Supercluster is inferred from the center of gravity of the galaxy motion around the galaxy, combined with the observed orbital trajectory of the present galaxy population. The giant Laniakea Supercluster is a stepping stone to our understanding of the Universe.
The scientists found that the galaxies in the Laniakea Supercluster move in the same direction from the plotted velocity lines, suggesting that a giant gravitational source is attracting them, and named this gravitational source the Giant Gravity Source.
How this gravitational source can have such a large gravitational force is still an unknown.
We determine that facts are also overturned, and our perceptions develop in the process, and we gain a deeper understanding of the universe in which we live. We stand on the mountain of past experience and knowledge and ask questions of the universe.