NOT DARK ENERGY, DARK FLUID

摘要

Dark energy could be weirder than we thought) Evidence that over large distances gravity exerts a greater pull on time than on space (see main story) might not necessarily suggest that the theory of general relativity is wrong. It could instead be a sign that the universe's acceleration may require a more exotic explanation. The simplest way of explaining the universe's acceleration is to invoke a cosmological constant, originally proposed by Einstein to allow the universe to remain the same size in the presence of matter. This describes a universe filled with uniform, outward-pushing energy.