The invisible backbone of our universe

When you first hear the term, "dark matter", you may be thinking this is some sort of complex enigma that humans haven't fully understood. I too had that same impression, but after some reading, it isn't that confusing to comprehend.

Let's break the term, 'dark matter' into 2 parts: 'dark' and 'matter'. Matter is something that has volume and occupies space. But why is it called 'dark matter'?

Dark matter is a hypothetical form of matter that does not emit or absorb light, hence, it is called 'dark matter'. It is impossible to detect it directly, which is why there are more unknowns than what is known regarding this field. Dark matter constitutes around 27% of our universe. The only way in which dark matter can be detected is through its gravitational effects, which can be observed in the movement of stars and galaxies.

As mentioned earlier, dark matter is impossible to detect due to its inability to interact with electromagnetic fields. The reason why dark matter does not interact with electromagnetic fields can be attributed to its lack of electric charge. Unlike ordinary matter which we encounter in our daily lives, these dark matter particles are electrically neutral. They can be compared to neutrinos, which are electrically neutral. As a result, these neutrinos are not affected by electromagnetic forces.

Ordinary matter is made up of baryonic matter, made up of baryons (thus, the name) such as electrons and protons. Cosmic objects such as planets or even black holes are made up of baryonic matter. We can see these objects because baryons interact with the electromagnetic force, one of the universe's four fundamental forces. When electromagnetic radiation falls on baryonic objects, they absorb photons (which make up light) and reflect them, allowing us to see these objects. Since dark matter does not interact with electromagnetic radiation, it does not interact with visible light so, we cannot see it.

Scientists have employed various techniques to indirectly study dark matter. One such technique is gravitational lensing, a phenomenon predicted by Albert Einstein in his theory of General Relativity. In his theory, mass causes spacetime to curve, causing the appearance that light bends around massive objects such as stars or galaxies. By observing this bending of light, scientists can infer the presence and distribution of dark matter.

In conclusion, dark matter constitutes a large proportion of our universe. Its perplexing nature has left scientists puzzled but through technological advances, scientists have come up with new ways to detect dark matter and explain more clearly the functioning of our universe.

Citations

Adam Riess. "Dark Matter." Britannica. https://www.britannica.com/science/dark-matter Accessed 24 June 2023.

The University of Hong Kong. "Astrophysicists reveal the nature of dark matter through the study of crinkles in spacetime." ScienceDaily. ScienceDaily, 25 April 2023.

www.sciencedaily.com/releases/2023/04/230425111243.htm. Accessed 25 June 2023.