Xinghan is brilliant, and the universe beyond the earth is vast beyond our imagination.

How big is the universe? Besides planets, solar systems, galaxies and super galaxies, what else is there in the universe?

Countless people have provided very good and detailed descriptions, but I want to share some images, which help to show the huge scale of the universe in an easy-to-digest way.

The first picture is the earth.

Illustration: Earth. Source: National Aeronautics and Space Administration.

solar system

Illustration: solar system. Source: usm

The star neighbors of the sun (each star marks a different solar system. Every one has a planet like us)

The Milky Way (it is estimated that there are 1000 billion stars, equivalent to 100000000 stars, many of which have their own star rows, just like the planets in our solar system).

Illustration: Milky Way. Source: Utah People's Post.

Local galaxy group (nearby galaxies) Each of these stars contains billions or even hundreds of billions of stars (just like our Milky Way), and most stars have multiple planets.

Virgo supercluster: The small cluster of galaxies next to "Local Cluster" (written in red below) represents all the galaxies shown in the above picture.

Illustration: Virgo supercluster. Source: moneyinc

Local supercluster-The cluster in the above picture is represented by the red virgo supercluster.

Hubble volume (the universe we see from the earth is called Hubble volume, which can be traced back to 65.438+0.36 billion years ago).

The estimated size of the universe (constantly expanding)

This has not taken into account the various theories of the multiverse. If these theories are accurate, you need to multiply this number infinitely. Such a huge scale will make the universe even more difficult to understand and still expand.

In our "known universe", there are more planets (such as the earth) that can support the existence of life than all the grains of sand in the beaches and deserts of the earth. This makes the earth, a living planet, not the only one in the universe.

Arthur C. Clarke said, "There are two possibilities: either we are lonely in the universe, or we are not. Both are equally terrible. "

The universe. -What's this?

Everything that exists, everything that has existed and everything that will exist.

Early humans were fascinated by the night sky full of countless stars and moons, and today we also see this charming starry sky. But the only difference is that early humans didn't know what it was, but today we have a little idea and understanding of what we saw in the sky.

The ancient Indian philosophy [Rigveda-BC 1500- BC 1200] described the whole universe as a "cosmic egg" or Brahma, which experienced a cyclical process of creation, destruction and rebirth. It shows that the whole universe or Brahmin expands outward from a concentrated point called Dubin, and then collapses again every 4.32 million years.

1568 The geocentric universe map drawn by Portuguese cosmologist Bacelo Meiu Velo.

Illustration: 1568 The geocentric universe map drawn by Portuguese cosmologist Bartholomeu Velho. Source: Dominican periodicals.

Aristotle, a Greek philosopher in the 4th century BC, proposed a universe with the earth as the center and all celestial bodies around the earth. He believes that the finite static universe exists in infinite time and will not change. Aristotle also believes that the universe is made up of five elements, four of which are the classic elements established before: fire, water, air and earth, and the fifth element he added: ether (filling the gap in the universe).

Since ancient times, human beings have been trying to crack the secrets of this splendid universe. But we can't fully understand it. But physicists are not ready to give up. As Einstein said in Physics and Reality (1936), "The most incomprehensible thing about the universe is that it is comprehensible."

Einstein's words gave them motivation, and people put forward different theories about the existence and origin of the universe.

Some physicists think that the universe is eternal and infinite, while others think that the universe is infinite and has a real origin. There is also a superstition that physicists believe in the finite universe. Different physicists have different views on the universe.

Illustration: BIGBANG. Source: New Scientist

Timeline of spatial scale expansion since the big bang

But the most widely accepted theory at present is the Big Bang theory, which supports that the universe is infinite (with infinite space), but it is still expanding. If we get an infinite inverse process, we call it "the inverse process of density". So everything exploded from a point138 billion years ago, which is also considered to be the age of the universe.

However, there are many inconsistencies in this theory. For example, everything that has its origin must have its end, but it says that the universe is infinite. Another question is why matter is more than antimatter (baryon asymmetry).

infinite universe

Space is infinite, matter and energy are infinite, which is entirely possible. This is a possibility of brain distortion, because the concept of infinity itself is very strange. The possibility of anything happening in the infinite universe is infinite. So anything we imagine can happen somewhere in the universe (no matter how likely it is, unless the probability is not zero). In an infinite universe, someone may be a billionaire like you. There may be a planet similar to Earth, where Stumm currency is more powerful than Bitcoin. So the possibility of anything happening is infinite, not once, but infinite.

But how can an infinite universe be more logical than what we see? Can an infinite universe expand from the Big Bang?

Yes, but the premise is that the big bang happened not only at a certain moment, but also anywhere at the same time.

NASA said on their website: "This shows that the scope of the universe is infinite; However, due to the limited age of the universe, we can only observe a limited volume of the universe. What we can really draw is that the universe is much bigger than what we can directly observe. "

Author: quora

Wei Wu

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