Universe’s Unsolved Mysteries – Within the world we live, what we don’t see is much more than what we see. And what we don’t know is much more than what we know. This is the best introduction to explain the topic of the article that focuses on the top mysteries of the universe: “Dark Matter” & “Dark Energy“.

But before we start discussing the topic, let’s agree on what the term “matter” means?

Normal Matter







Normal Matter (NM) is everything you see. Yes! Your car, wallet, phone, and other objects are made up of matter. Even yourself! However, regarding particle physics, NM is comprised of atoms which in turn constitute of protons, neutrons, and electrons. And this is what physicists and astronomers call “matter”.

The surprise is that this visible matter makes up only 5% of our universe. Other terms describing this phenomenon are “ordinary matter” and “baryonic matter” where baryons are subatomic particles made up of quarks. Baryons such as protons and neutrons are fundamental constituents of ordinary matter.

Universe’s Unsolved Mysteries

Dark Matter

Dark Matter (DM) are invisible substances that are freely-moving particles and make up 25% of the Universe. It is the second type of matter which so far is still a mystery to scientists. DM is responsible for holding galaxies and other matter together by force of gravity. Without DM, our universe will not have today’s shape and arrangement.

What makes DM invisible is the fact that it does not interact with electromagnetic forces thus it doesn’t absorb or emit light. Another interesting fact of DM is that it interacts ordinary matter only weakly and gravitationally. We divide DM into two categories: Neutrinos, being the hot matter traveling nearly at the speed of light, and cold DM particles that move slowly.







Dark Energy

Dark Energy (DE) is another mystery in physics. The surprise is that DE makes up 70% of the universe and is also invisible. To define DE, we must at first introduce a discovery by the Hubble Telescope which indicates that our universe is expanding. And this expansion of the universe is accelerating.

Thus, DE is an anti-gravity force stronger than DM and works against it to fill in the empty space that’s taking place during the universe expansion. As you notice, DE is not detectable. And how can it be if it’s not a particle at all? It is a force that influences DM and NM only via gravity.

Conclusion

To sum up all the information above about the universe’s unsolved mysteries, we can claim the following: