I read an article at,https://www.universetoday.com/113786/how-big-is-the-universe-2/ , it talks about how the universe is expanding. The light takes time to travel from these distant galaxies that are far way. The problem is talking about how big these galaxies are. A lot astronomers don’t worry at all about the distance of galaxies.
They mostly focus on redshift in which they measure it by z. Bigger the z, the more redshift, which means the more distant the galaxy is. The most distant galaxies that they have measured has a redshift of 7.5. By using this, they can now determine the distance by calculating the length of the light from the other galaxy.
A red shift of 7.5, comes out to be approximately 13 billion years. It’s not 13 billion light years away, its 13 billion years ago the universe was smaller, which was actually closer at the time. Calculating that distance, it is only 3.4 billion light years away. The galaxy is of course a lot more further than that. The galaxy keeps moving away from us. The co-moving distance of the cosmic background is around 46 billion light years. The observable universe had a diameter of around 92 billion years.With the observed distance, it even extends more than that. It has a diameter of about 92 billion light years.
This article relates to this objective because it talks about the main objective about the size of the universe. I personally like this article I feel that I learned a lot of good facts from it. I learned from the article that there are some ways of calculating it. I also learned a lot in my class in fact I learned about how all galaxies move away from us which it also explains the same thing in the article. I learned that all galaxies are attracted to each other by gravity. As an elliptical passes through, the stars do not collide. The increased density and gravity creates new stars which I found pretty fascinating.