Why would cosmologists expect the rate of expansion of the universe to be slowing down?
A) The gravitational pull of all objects in the universe on each other would lead to slowdown.
B) All expansions after explosions naturally slow down with time.
C) Galaxies feel a kind of friction as they move through space, which slows them down.
D) The greater the distance between two objects (such as galaxies or superclusters), the harder it is to push them farther apart.

Question

Quizplus · Accepted Answer

The gravitational pull between all the objects in the universe acts as a force that would naturally slow down the expansion of the universe, as each object exerts a pull on every other object, potentially decelerating the rate of expansion.

Why Would Cosmologists Expect the Rate of Expansion of the Universe