Dark Matter and Dark Energy

Dark matter

Dark matter along with dark energy accounts to occupy 95% mass-energy in the universe.  Dark matter is called dark because it does not interact with the electromagnetic waves, which means it doesn't absorb, reflect or emit electromagnetic radiations, and is therefore difficult to detect. Its presence matters because of some  astrophysical observation which includes gravitational effects which could not be explained by theories of gravity unless there must be something else present which cannot be physically detected, so many experts think that Dark matter is present in abundance in the universe which is responsible for the structural and evolution of the universe. 

Evidence from calculations show that galaxies wouldn't stay where they are or may have never been formed if they wouldn't contain extensive amounts of unseen matter. This matter is responsible for orbits and movement of galaxies. In total 95% of total mass-energy content, about 27% is dark matter and 68% is dark energy which is discussed further. Extreme gravitational pull at centre of the black hole can be due to presence of dark matter.

 

Dark matter is not observed directly yet but if it exists then it must rarely interact with ordinary matter except for effects in gravity. Dark matter may be formed of some undiscovered subatomic particle. The foundation or basic component of dark matter may be some undiscovered elementary particle. If we somehow manage to detect and find a way to store dark matter we might be able to create artificial gravity. We will discuss artificial gravity later in depth.

Dark Energy

In astronomy dark energy is the energy which has its largest effect in the universe. The initial evidence of dark energy came from studies that showed that the universe is not expanding at a constant rate but its expansion is accelerating, so without introducing a new form of energy it was impossible to explain how expansion of the universe was accelerating. Since the 1990s dark energy is the most suitable explanation for the accelerated expansion of the universe. The density of dark energy is very low, much less than the density of ordinary matter or dark matter within galaxies. However, it dominates the mass–energy of the universe because it is uniform across space.

Nature of dark energy is much more complicated than dark matter. Dark energy is thought to be homogenous and not so dense and it does not interact with any fundamental forces other than gravity. But at last when we consider all things there is more unknown then known.