dark energy, is proposed to be a repulsive force that would cause the universe to expand. The expansion rate is related to the sum of the densities of each substance. According to the data of the WMAP satellite, 72% of the universe is composed of dark energy, 24% of the universe is dark matter, and 4% is normal matter. The proportions of dark matter, normal matter, and dark energy are such that the universe’s expansion is currently accelerating; however, we do not know for sure what the expansion rate will be in the future.
With the discovery of the expanding universe, astronomers realized that the universe is a dynamic, evolving environment. While the universe has been expanding ever since the Big Bang, a natural question is, will that expansion continue forever? In other words, what will be the final fate of the universe?
What is the ultimate fate of our universe? A Big Crunch? A Big Freeze? A Big Rip? or a Big Bounce? Current observations have led cosmologists to favor “The Big Freeze.” However, the other three theories still cannot be totally ignored until the dark energy is fully understood.
- Cora Wu