What is Dark Matter?

Dark matter. Dark matter has left scientists puzzled for many years. Let's start by defining regular matter. Matter is anything that occupies space and has mass. All physical objects contain matter. A qualitative observation of matter is its' state or phase. The three most common states of matter are solid, liquid, and gas. Now, lets' define dark matter. Dark matter is composed of particles that do not absorb, reflect, or emit light. Since dark matter does not emit light, we cannot detect it using Electromagnetic Radiation. We cannot see dark matter, but we know it exists because of the effect it has on objects that we can observe directly. 

What are some things we know are made of dark matter? Primordial, Super-Massive, and Intermediate-Mass Black Holes are all made of dark matter. Dark Matter makes up about 27% of the Universe. What is dark matter made of? Dark matter might consist of an as yet unidentified subatomic particle of a type completely different from what scientists call baryonic matter, which is just regular matter. 

According to standard physics, stars at the edges of a spinning, spiral galaxy should travel much slower than those near the galactic center, where there are clusters of a galaxy's visible matter. But careful observations show that stars orbit at more or less the same speed regardless of where they are. This result makes sense if one assumes that the boundary stars are feeling the gravitational effects of an unseen mass-Dark Matter. 

Scientists have been studying dark matter for 88 years but we still don't know why this strange force exists in the first place. We have made many promising discoveries during the time of study and soon will uncover the mystery of where dark matter came from. 

Works Cited

https://www.sciencelearn.org.nz/resources/236-matter-in-our-world

https://starchild.gsfc.nasa.gov/docs/StarChild/universe_level2/darkmatter.html