Dark_Energy

Dark Energy What is dark energy' If you are unsure you are not alone, many people have never even heard of it. Personally, I had never heard of it until I read a cosmology textbook. Throughout the course of this essay I will discuss what dark energy is, what it does, how it is observed, why it is important and the role it plays in astronomy and cosmology. After reading this essay you should have a good understanding of what dark energy is and how it works. Dark energy is an extra “ingredient” that cosmologists require in order to balance the density of the universe and account for why its expansion is accelerating. Dark energy seems to be equally distributed through all of space unlike matter which clumps together under the influence of gravity. This causes it to affect the global properties and expansion history of the universe as a while without affecting localized blobs of matter which also does not influence dark energy itself. Dark energy makes up m ore than 70 percent of the mass-energy of the universe. It has a repulsive influence that is insignificant compared to gravitational attraction of matter. It is wasn’t so insignificant than it would have prevented matter from coming together to make stars, galaxies and clusters. For dark energy to be the major component of the cosmic mass-energy now and an insignificant one in the past its density must remain the same or change at a slower pace than the density of matter. With expansion of the universe, the density of matter and dark energy decreases. Dark energy changing slowly or not at all and matter changing rapidly, dark energy will eventually become the dominant component. In our 13.7 billion-year-old universe, the time of dark energy domination is fairly recent.