How big is the universe?

How big is the universe? The James Webb Space Telescope, 1.5 million kilometers from Earth, tells you the answer.

Following the Hubble Space Telescope, the James Webb Space Telescope was launched and successfully reached the sun's orbit around the sun-Earth L2 Lagrange point, about 1.5 million kilometers from Earth.

Billed as the most powerful telescope in history, it will be tasked with observing the first stars and galaxies after the Big Bang, as well as looking for potentially habitable exoplanets.

On July 12, 2022, the first full-color images and spectral data from the James Webb Space Telescope were officially released. When the photos were released, they shocked astronomers, made people think, and even the melon eaters were shocked to see them.

On July 12, 2022, the first full-color images and spectral data from the James Webb Space Telescope were officially released. When the photos were released, they shocked astronomers, made people think, and even the melon eaters were shocked to see them.

Which begs the question, what's going on in these photos? What exactly does it tell us?

The first of five images, including the first deep-field image, shows a galaxy cluster named SMACS 0723.

This image contains thousands of galaxies like the Milky Way, along with three stunning pieces of information.

The first is time. This image shows what the cluster looked like 4.6 billion years ago, when the solar system and even Earth were just born.

Second, in space, it's 5.12 billion light years away (that's because the universe is expanding, considering the inflation effect). When the James Webb Space Telescope photographed it, it captured an area of sky roughly equivalent to a person holding up a grain of sand with their arm straight up toward the sky, and the sand covered a patch of sky. Thousands of galaxies from a tiny space.

This means that if our eyes had the power of the James Webb Space Telescope, we would be looking at a sky full of stars.

Finally, in this image, there are a lot of round or oval blobs in the center, which are actually galaxies in this cluster, and there are a lot of curved curves around them.

They're actually much more than 5.12 billion light years away, more than 10 billion light years away, very, very far away objects, and it's only because SMACS 0723 bends the space-time around it, bends the light of these objects, that we can see, and it acts like a lens, like a magnifying glass, This phenomenon, also known as gravitational lensing, was tested by Einstein's theory of general relativity. In other words, it invisibly proves the accuracy of relativity.

The fact that we have so much information about so many objects from such a small area of the sky shows the importance of this image. But beyond that, there's a lesson to be learned: The universe is much bigger than our imagination. Why do you say that?

What this picture tells us is that if you look from any direction on Earth, as far as you can go, you can see a lot of celestial objects, as previous Hubble observations have shown. This means that the universe around the Earth is almost the same. Is the Earth the center of the universe?

No! That's not accurate. In fact, it's more like the universe is so big, it's almost infinite, so it's centered everywhere, and no matter which way you look, you can't see the edge of the universe. Don't believe it? Let's take a look at some previous findings! Humans have been wrong about the Earth.

Human knowledge of the universe

In the beginning, people thought that the Earth was the center of the universe, and all the celestial bodies moved around the earth. For this reason, people drew very complex geocentric models.

However, later Copernicus, Galileo, Kepler and other observations found that the earth is not the center of the universe, the sun is more likely to be the center of the universe, and put forward the "heliocentric theory".

Newton, however, completely destroyed the geocentric and heliocentric theories, because the Newtonian view of the universe was supposed to be infinite, dominated by gravity.

Einstein, in his general theory of relativity, added a universe that, as they say, is static at large scales, and this is Einstein's model of an infinite static universe with an edge.

However, the universe is never subject to human will. Later, Mellors and Hubble found that the universe is not stationary, but will expand. Astronomy was developed again, and the "Big Bang" theory and the standard model of the universe were put forward.

From the development of astronomy, we can see that the progress of science has made us more and more aware of our own insignificance, from thinking of the Earth as the center of the universe, to the Earth as a mere presence in the universe.

It also makes more and more people wonder how big the universe is and how small humans really are.

How big is the universe?

The size of the universe can be divided into three dimensions:

Time perspective

In the past, we thought the universe was static and unchanging, but when Hubble looked at galaxies outside the Milky Way, it found that most of them were redshifted, which means they're moving away from us.

And the farther away the galaxy is, the faster it moves away from us. And that makes you wonder, you know, if it's just individual galaxies moving, then some galaxies are moving towards us, some galaxies are moving away from us, why are they all moving away from us?

Scientists have come up with a theory: the universe is expanding. We can think of the universe as a balloon. As the balloon gradually expands, distant galaxies do move away from us.

Conversely, the fact that the universe is expanding suggests that it should have held together in its early days, a point scientists call a singularity. The singularity is infinitely small, infinitely hot, infinitely dense, and after it comes the Big Bang.

Scientists have found that the universe began 13.8 billion years ago, around the time of the Big Bang. However, the Earth did not form until 4.6 billion years ago, when the matter was pulled together by gravity to form the sun, and the waste material that formed the sun formed the planets, moons, asteroids and so on in the solar system.

The Earth began 4.6 billion years ago, but it wasn't until about 4.2 billion years ago that life began to appear on the Earth. Life evolved, and various creatures took turns to dominate the Earth, only to be shuffled out of the poker table in mass extinctions.

The rise of human beings is also in the last few hundred thousand years, 200,000 years ago in the African region evolved early Homo sapiens, 65,000 years ago, Homo sapiens began to move out of Africa, spread all over the world, evolved into what we are today.

Human civilization was born about 10,000 years ago, but for a long time in the past, human understanding of the universe was only a drop in the bucket. It is only in the past 200 years, with the continuous development of science and technology, that we gradually learned from modern scientific instruments how big the universe is and how small human beings are.

From a time perspective, the universe has been around for 13.8 billion years, and human civilization has only been around for 10,000 years or so, which makes the universe incredibly large.

Space Angle

From a spatial point of view, humans are almost negligible.

We know that human beings live on the Earth, and the Earth is just an ordinary member of the solar system. The solar system is very big, so big that the first unmanned spacecraft sent by our human beings has been flying toward the edge of the solar system for more than 40 years, but still has not flown out of the solar system, at least it will take more than 30,000 years to fly out of the solar system.

You might think that the solar system is big enough, but in fact, the solar system is just a normal member of the Milky Way, the number of stars in the Milky Way is between 100 billion and 400 billion, the solar system is so small that the Milky Way would not even know if it disappeared.

The Milky Way is large enough, but it is also a member of the local group of galaxies, there are dozens of galaxies like the Milky Way, about 10 million light-years across.

The material point of view

From the point of view of space and time, the universe is beyond human imagination, but you think this is the existence of human insignificant?

No, no, no!

From a material point of view, human beings are small to almost negligible!

There are four major interaction forces in the universe: electromagnetic force, gravity, strong interaction force and weak interaction force.

What we can see depends on electromagnetic forces, but what if we had a substance that didn't interact with electromagnetic forces?

In fact, we wouldn't be able to see it, as is the case with dark matter and dark energy, which don't engage in electromagnetic interactions, so we wouldn't be able to see it.

However, the study found that dark matter and dark energy are the majority of the universe, they make up 95% of the matter, while the matter visible to humans is only 5%. This shows that even in the same space and time, there is a lot of matter that we can't see, but it is still in the universe.