Term

Dark energy

The name for the unknown cause of the universe’s accelerating expansion. It is different from dark matter.

The Edge of Space-Time, Chanda Prescod-Weinstein

Explained in

• The Edge of Space-Time, Chanda Prescod-Weinstein
• Until the End of Time: Mind, Matter, and Our Search for Meaning in an Evolving Universe, Brian Greene

  The working name for whatever drives the accelerating expansion of the universe. The effect is measured, but its nature is still unknown.

• Astrophysics for People in a Hurry, Neil deGrasse Tyson

  The name for the unknown cause of the universe's accelerating expansion. The acceleration has been measured, but what drives it has not yet been established.

• Parallel Worlds: A Journey Through Creation, Higher Dimensions, and the Future of the Cosmos, Michio Kaku

  A name for the unknown cause that makes the expansion of the universe speed up. The effect is observed; its nature is not yet understood.

All terms