SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/astro-dark-energy-acceleration

What observed cosmic behavior is attributed to dark energy?

The universe's expansion is speeding up.

Start playing free

  1. Accelerating expansion ✔
  2. Galaxies stopping their rotation
  3. Stars losing all gravity

Why: Distant supernova measurements showed that expansion did not merely continue. It accelerated, leading astronomers to name the unknown cause dark energy.

Huh, didn't know that: The acceleration began billions of years after the Big Bang, after an earlier era when gravity slowed expansion.

The dad joke
Dark energy saw the speed limit and expanded on the idea.
Like this card?
Play the game

References

Answer: Accelerating expansion. Distant supernova measurements showed that expansion did not merely continue. It accelerated, leading astronomers to name the unknown cause dark energy.

  1. What Is Dark Energy? science.nasa.gov/dark-energy
    it's making the universe expand at an accelerating rate
    Checked 2026-10-10.

Think this answer is wrong? Tap "Challenge this answer" on the card in the game and tell us why.

Test yourself in the game

Astronomy & SpaceApproximately what share of the universe is dark energy?Astronomy & SpaceAbout what fraction of cosmic critical density is dark matter?Astronomy & SpaceDid the Big Bang occur at one location inside preexisting space?

That's stuff everyone should know.