How Big Is The Universe?

Published in

Storytellings

5 min readAug 17, 2021

Anyone has probably thought about questions like “how big is the universe” or “what’s out there”. Before we can explain these questions, we need to address what our address is in the universe. We all know our home address. So what is our address in the universe?

Earth

Third Rock from the Sun

Solar System [1]

Orion Arm [2]

Milky Way Galaxy [3]

Local Group of Galaxies [4]

Virgo Cluster [5]

Laniakea Supercluster [6]

This Universe

This is the address of the Earth in the universe. Then you can add your home address in front of it. This is the exact location of our home in this universe.

Next, we will use this address to analyze how big the universe is. Solar System; Third Rock from the Sun; Earth. We all understand those terms.

Orion Arm

Milky Way Galaxy

The Milky Way Galaxy is a spiral-arm galaxy. Galaxies have many different shapes. Some look like wheels. Some rotate like a “Z”. The Milky Way Galaxy has four large spiral arms. They are the Norma and Cygnus arm, Sagittarius, Scutum-Crux, and Perseus. And we are not on these four big arms. Instead, we are on a smaller arm — Orion Arm.

The diameter of the Milky Way Galaxy is 100,000 light years [7]. So our Solar System is a small place in the galaxy. Solar System is exactly half of the radius of the Milky Way Galaxy.

Solar System is about 25,000 light years from the boundary of the Milky Way Galaxy [8]. It will take another 500 million years for the Voyager to fly out of Solar System and another 500 million years to fly out of the Milky Way Galaxy.

The diameter of the Milky Way Galaxy reaches 100,000 light years. This diameter is particularly large, so most of the areas of the Milky Way Galaxy are empty. In the space of the universe, there are really too few stars. It is like a huge space with countless amounts of dust.

The closest galaxy to our galaxy (The Milky Way Galaxy) is the Andromeda Galaxy. And the Andromeda Galaxy is twice as big as the Milky Way Galaxy. The largest known galaxy is IC1101, which is ten times larger than the Andromeda Galaxy [9].

The Andromeda Galaxy is 2.5 million light years away from the Milky Way Galaxy. It is now approaching us at a speed of 120 kilometers per second [10]. In the next two to four billion years, the Andromeda Galaxy is expected to collide with our own galaxy. It will eventually merge into one galaxy. The process of fusion does not happen as soon as the galaxies collide. Instead, it will collide and separate, collide and separate again, and finally merge together little by little.

The fused galaxy is expected to be called the Milkomeda Galaxy [11].

A collection of stars is called a galaxy. The combination of galaxies is called a galaxy cluster. The Milky Way Galaxy, the Andromeda galaxy, plus a Triangulum galaxy, and some particularly small surrounding galaxies, combine to form this Local Group of Galaxies.

The Local Group of Galaxies has a diameter of 10 million light years [12]. But most of it is empty. The Local Group of Galaxies is the galaxy group we’re in and a hundred more galaxy groups grouped together. This makes up the Virgo Cluster. The Virgo Cluster is about 110 million light years in diameter.

In 2014, a team of researchers from Claude Bernard University Lyon 1 and the University of Hawaii discovered that the Virgo Cluster, which we are in, is actually part of a much larger structure. This larger structure is called the Laniakea Supercluster. This supercluster is 520 million light years in diameter. It is five times larger than the Virgo Cluster. It contains 3 main superclusters of galaxies:

Virgo Supercluster (the region where we live)

Hydra-Centaurus Supercluster

Pavo-Indus Supercluster

These 3 superclusters were originally separate galaxy clusters, but were later found to be getting closer and closer together. In the middle of these 3 superclusters is a gravitational anomaly. This is not a black hole, it is called a Great Attractor [13]. Great Attractor is much larger than the black holes we know. It is a very rare super gravitational center in the entire universe. At present, humans cannot observe the Great Attractor.

What is the size of the known universe? 46.5 billion light years in radius. That is, 93 billion light-years in diameter. This area is known as the “Observable Universe” [14].

There are so many superclusters of galaxies scattered throughout this empty universe. They seem to be unconnected to each other. In fact, they are all pulling on each other. Eventually they form a network. Scientists drew the structure of the universe, found that the structure of the universe and the structure of the human brain are almost the same [15]. To be specific, The neural network of the human brain and the structure of the universe are almost the same. Maybe the universe is actually a biological brain, we are living in the neurons or brain cells.