@susan how is dark energy affecting how fast the universe is expanding?

Question: @susan how is dark energy affecting how fast the universe is expanding?
- Keywords:
  dark matter,
  energy,
  universe
Asked by Ellie C to Susan on 16 Jun 2015. This question was also asked by the josh.
- Susan Cartwright answered on 16 Jun 2015:
  
  The effect of dark energy is to speed up the expansion – you can think of it as a kind of antigravity. We can see this directly by looking at supernovae (which can be seen at large enough distances for the effect to be visible).

Question: @susan how is dark energy affecting how fast the universe is expanding?