Explaining constituents of the universe is not easy even at the current stage of astronomic progress. Today we know that the universe is full of solid objects which are grouped together and, certainly, of energy. But if we have plenty of data on planets, stars, and their properties, energy remains to be an ambiguous component.
Taking into account the Einstein’s theory, there must be nothing difficult in explaining the energy which fills the universe. The Big Bang released enough energy to cause the expansion of the universe but a decade ago scientists were still uncertain about the scale of this expansion. From the point of view of the Einstein’s theory, mass created gravity which constantly pulled objects together. Astronomers anticipated that the universe is slowing the expansion. Nevertheless, the observation of supernova showed that the universe is, on the contrary, accelerating the expansion due to some unknown mysterious force. “Something” which is neither matter nor ordinary energy was called dark energy.
Scientists are still uncertain about what so-called dark energy actually is. Perhaps it is some fluid-like substance or a weird property of the empty space which has not been properly discovered before. Anyway, researchers concluded that dark energy has a visible effect on the expansion of the universe. The latest NASA research confirms that the amount of dark energy has not changed over the time of its existence. Results obtained with Chandra X-Ray Observatory support Einstein’s idea of “cosmological constant” which explains dark energy as the energy of empty space.