It might sound odd to anybody who is not from a scientific background that we only know just about less than 5% of the universe. So our understanding of the known universe is minuscule in comparison to what we don’t know. It is estimated that 28% of the universe is dark matter while a whooping 67% is dark energy. But now the question is what are these dark matter or dark energy?
Dark Energy
We really don’t know? It is still a mystery. This is a hypothetical concept that counteracts gravity, letting the universe expand. So the accelerated period of expansion of the universe made it possible for the conception of dark energy. To further simplify: Our universe has a lot of massive objects,and the gravitational force between these objects makes the universe collapse, however we see that the universe is expanding at an accelerating speed. So, how does this happen, what counteracts the gravitational force between these massive stellar structures. Here comes into the equation what is called dark energy; dark energy is the repulsive force that helps in the expansion of the universe.We can also see the effect of dark energy in the formation of galaxies as a result of gravitational instabilities.
The Dark Matter
Now that we have somewhat an initial understanding of what dark energy is, let’s look into dark matter. The dark matter is detected with the help of its gravitational interaction with the normal matter. Even though dark matter has interactions with normal matter it very much differs from normal matter in its interaction with EM waves, there is no interaction with light at all: no emission, absorption or reflection. There are many assumptions about what could be this dark matter; if speculations and assumptions are concerned for all we know dark matter might contain supersymmetric particles.