Everything in the universe is made up of matter – the galaxies, the stars, you and me. But, that is what we thought to be true. Here you will learn that all the more matter hiding in the dark than meets the eye…..
A few decades ago, astronomers discovered that mass of all the matter in galaxies is not enough to counter the centrifugal force produced by the galaxy’s rotation. As a result we must be seeing all the stars of the galaxy flying off into the void of space. But that is not the case. We see that galaxies are structurally stable. So what is this mysterious matter that is giving galaxies the extra mass? We call this dark matter. It makes 25% of the universe. But, why is it dark? It does not interact with electromagnetic waves this making it undetectable but we know that it exists because of the gravitational effects of this mass. So dark matter basically binds the galaxy together. Almost every galaxy, including our own has dark energy holding all of their mass together.
Dark energy makes up 70% of the universe. It is a mass that curves the fabric of space in such a way that it creates a form of gravity that is repulsive. It is spread uniformly throughout the universe. This mass is responsible for the accelerating expansion rate of the universe.