- The universe is full of matter and the attractive force of gravity pulls all matter together.
- a long time ago, the universe was actually expanding more slowly than it is today
- So the expansion of the universe has not been slowing due to gravity, as everyone thought, it has been accelerating
- Dark Matter is a form of matter thought to account for approximately 85% of the matter in the universe and about a quarter of its total energy density.
- Dark Energy is an unknown form of energy which is hypothesized to permeate all of space, tending to accelerate the expansion of the universe
- It turns out that roughly 68% of the universe is dark energy.
- Dark matter makes up about 27%.