Why do scientists say that human beings will never reach the boundaries of the universe?
After reading it, you will understand
This is a part of the Earth photographed by astronauts on the space station, when the earth is no longer flat and the curvature of the Earth begins to appear.
This is a panoramic photo of the earth taken 30,000 kilometers from the earth, and we can clearly see the whole earth.
This is a photograph of the Earth from the moon 380,000 kilometers away, and under the effect of the perspective principle, the earth has become a small blue marble, and the resulting panoramic effect has even caused fear among many astronauts who have landed on the moon.
Leaving the Earth-Moon system, the Earth will become smaller and smaller in our eyes, and you see this dim picture now, which was taken by Curiosity on Mars 160 million kilometers away, and that little white dot is our Earth, which is a picture of the Earth taken by Cassini under the rings of Saturn, which is 1.4 billion kilometers away from the Earth at this time.
This famously faint blue dot image was taken by Voyager 1 from 6.4 billion kilometers away from Earth, which at this time occupies only 0.12 pixels, in the words of Carl Sagan: Earth is a speck of dust suspended in sunlight.
Our solar system is 2 light-years in diameter, and above it is the Milky Way, which is 100,000 light-years in diameter and has at least 100 billion stars, and the Drake equation shows that there are at least dozens of alien civilizations in the Milky Way, but they are too far apart from each other, so we have not found aliens until today.
The Local Group of Galactic Galaxy, which covers more than 50 galaxies including the Milky Way and the Andromeda Galaxy, has a diameter of a staggering 10 million light-years, but it is only a small part of the Virgo Supercluster.
The Virgo Supercluster covers a huge region with a diameter of more than 110 million light-years, and there are at least 100 systems like the Local Group of galaxies.
There is also the Laniakea Supercluster, which consists of 100,000 galaxies and reaches a diameter of 520 million light-years, which means that it would take us 520 million years to fly out of its range even if we were piloting a spacecraft at the speed of light.
When we reach the scale range of 1 billion light-years, the universe is no longer the evenly distributed structure of galaxies in our impression, but has become a network structure, tens of thousands of galaxies driven by dark matter and dark energy, into a great wall of the universe spanning 10 billion light years, and superclusters of galaxies have become the nodes of the great wall of the universe, which are divided by cosmic holes of tens of millions to billions of light years, until the edge of the observable universe.
The current observable universe refers to the spherical space-time with the earth as the center, a radius of 46.5 billion light-years, and a diameter of 93 billion light-years, in which there are at least 2 trillion galaxies, but this is far from the size of the real universe, this is only because of the light emitted by distant galaxies, because the universe expands beyond the speed of light and cannot fly to the earth, and forms a limited space.
Scientists speculate through computational analysis that the real universe may be more than 250 times the size of the observable universe, so human beings may really never reach the edge of the universe, after all, even if we fly at the speed of light, the expansion rate of the universe is faster than the speed of light, and we will never be able to catch up with the edge of the universe.