Hubble Trouble: How fast is the universe expanding?
What is Accelerating Expansion of the Universe | Evidence for Acceleration Physics Concepts
the acceleration of the universe
Does the Universe Have an Edge - Universe Expanding Faster Than We Though Documentary
The accelerating expansion of the universe is the observation that the universe appears to be expanding at an increasing rate, so that the velocity at which a distant galaxy is receding from the observer is continuously increasing with time.