The term “dark energy” was coined by Michael Turner (or his student Dragan Huterer) in 1998; it is meant to be distinct from the “inflation” that occurred at a much higher density in the early universe. There are good reasons to favor another term for dark energy. I prefer “levity.” Here’s why:
‣ Levity works in opposition to gravity. Linguistically, the terms are opposites.
‣ Dark energy was chosen as the name for the phenomenon because dark matter was being studied at the same time. The two may have no genetic relationship.
‣ Dark matter is dark because it can’t be detected optically. Dark energy is dark because its action is unknown. Those features are not equivalent. With luck and perseverance, the action of dark energy will be discovered.
‣ It’s easy to teach the concept using the term “levity.” People intuitively know what it means.
‣ “Dark energy” feeds into the media misconception that science is somehow mysterious and difficult to grasp. The reality is that science is very clear but based on a demanding process.
‣ Levity in common usage includes an aspect of nonlinearity and perhaps an odd localization. I assume that the phenomenon of dark energy has congress with both of those concepts as well.
‣ Levity in common usage is a healthy and fairly routine part of human existence. I assume that the phenomenon of dark energy will likewise be found to be a common feature of the physical world.
Considering that undergraduate students are still taught to write electrical current flowing from + to –, I see little possibility for such a simple improvement as the one I’m laying out. I hope I’m wrong. The change could happen, but it would take an effort. People would have to use the term commonly, and it would have to become popular.