WHATS THE RELATIONSHIP BETWEEN MASS DENSITY AND AGE OF THE UNIVERSE?
The rate of the Universe’s expansion reflects how much gravity and hence, matter, it has. Like going up a steep hill, the galaxies outward rush should have slowed if the Universe has a lot of mass, and this implies a younger universe. If the Universe has little mass, and so is barely decelerating, then galaxies would have taken more time to reach their current positions, like rolling along a flat floor. The rate of the Universe’s expansion should be slowed by the mutual gravitational pull of all matter contained in the Universe.
