universe
The universe is composed of space, time, material and energy, constitute the unity. Is the sum of all space and time. The general understanding of the universe refers to the existence of a space-time continuous system, including all the material, energy and events. The overall interpretation of this system constitutes cosmology. In ancient China there is "up and down the Quartet said Yu, to ancient times today, said the universe," the argument, the universe is also from the "next day, relying on the universe." For centuries, scientists based on modern physics and astronomy, the establishment of the universe on the modern scientific theory, known as the physical cosmology. According to the theory of relativity, the speed of information transmission is limited, so in some cases, for example, in the case of the expansion of the universe, we will only receive a small area of information from the area where we are very far away. Will never be able to spread to our area. The space-time part that we can observe is called "observable universe", "visible universe" or "our universe". It should be emphasized that this is due to the structure of space itself, and we have nothing to do with the observation equipment used. The universe is made up of 4.9% of the common matter, 26.8% of the dark matter and 68.3% of the dark energy. ...