Dark Matter

Credits: Image by N Jeffery/Dark Matter Collaboaration

The detectable and visible matter in the universe like planets, stars and galaxies take up only 5 percent of the universe. Dark matter interacts with gravity but cannot be visible with light or electromagnetic waves which makes it impossible to learn more about it. Some evidences that dark matter is real is because we now know that a star orbits at about the same speed anywhere in the spiral galaxy. It makes sense for the farther stars from the center to orbit slower than the inner stars which get pulled to the center of the galaxy. This is because a force called dark matter is exerting gravitation force on the outer stars of a galaxy making all stars of in a spiral galaxy to orbit at about the same speed. With the universe expanding rapidly with dark energy but this slowed down because of dark matter. Some characteristics of Dark matter is that dark matter cannot emit or reflect light which is why we can't see it or detect it. In areas of space where there is a lot of dark matter it can bend light. A possible proof of this is because when astronomers have observed galaxies they have seen a light rings with it and this possibly the light from another galaxy that is just getting warped from the dark matter which has the ability to bend light. One thing that is certain is that dark matter is not antimatter because antimatter gives of gamma-waves when it comes in contact with normal matter. Dark matter is considered as non-baryonic because it has particles that is not baryons like ordinary matter. Ordinary matter has baryons which is composed of particles like protons and neutrons inside an atom whereas dark matter has other type of subatomic particles which we have not discovered yet.

Dark matter and dark energy are two things we don't know much about in space but with so many evidences of its existence we know there is something out there in space like dark matter and dark energy. I think dark matter is a really important subject because without it the galaxies would be broken up because of the rapid growth of the universe. Learning more about dark matter we will learn more about how the universe is expansion.