The Universe

Our best model for the Universe is called ΛCDM. Λ, which stands for dark energy (DE), makes up 70% of the Universe, and cold dark matter (CDM) about 25% of the universe. The remainder is normal matter, which is everything we can see.

The Earth is a tiny part of one galaxy, and our Universe contains billions of trillions of galaxies. But what is a galaxy anyway?

If dark matter is invisible but is a large part of the universe, how do we know that it even exists in the first place?

When we talk about what the universe is made of, we separate dark matter and galaxies (normal matter). However, they are very closely related to each other.