| Main Entry: | dark energy |
| Part of Speech: | n |
| Definition: | in physics, a hypothetical force that affects the behavior of photons, counteracts gravity, and causes the universe to expand at an ever-increasing rate |
| Example: | Dark energy was first proposed by Albert Einstein to balance gravitation. |
An as yet unknown and unidentified form of energy that pervades the universe and produces a force that counteracts the gravitational attraction between galaxies.
Note: Dark energy is thought to be responsible for the accelerating universe.