Final answer:
The expansion of the universe is currently speeding up, due to the influence of dark energy which counteracts the expected decelerating effect of gravity.
Step-by-step explanation:
The expansion of the universe is a key concept in astrophysics. Initially, it was thought that the expansion rate of the universe was slowing down due to the gravitational pull of matter. However, more recent observations have shown that the universe is actually expanding at an accelerating rate, which challenges our understanding of gravity and introduces the concept of dark energy.
This dark energy is thought to be causing the acceleration of the current expansion, leading to a universe that expands faster and faster over time, contrary to the decelerating expansion that would be expected if gravity were the only influence.