As the universe expandes is does not maintain a constant expansion speed, the expansion speed of the universe gets faster and faster. Spacetime itself is speeding up throughout the entire universe. Everything in the universe is speeding up. but we dont notice this so obviously, we can look at a clock and see that as usual time maintains a constant speed.... But Spacetime itself is widespread and affect all things in the universe.

 

Is Spacetime Speeding up as the Universe Expands?

The evidence is showing us that the expansion of space-time is accelerating. This has opened interest in the cosmological constant again and related theories that use scalar fields.

 

We don't notice this expansion until we get to the scale of galactic clusters as local gravity can overcome this global expansion.