Is the universe really expanding? If so,how do we describe the expansion?
A) It is not expanding-it is our local space that is getting smaller as we fall into a supermassive black hole,making the universe seem bigger and bigger.
B) Space itself is expanding,carrying the galaxies (or superclusters of galaxies)with it.
C) An infinitely small but infinitely dense clump of matter exploded,sending the galaxies (or superclusters of galaxies)hurtling out through space.
D) The energy from all the stars is heating the universe,making it expand like a gas that is heated.

Question

Quizplus · Accepted Answer

The expansion of the universe is supported by various observations, such as the redshift of light from distant galaxies and the cosmic microwave background radiation. The current leading theory is that space itself is expanding, carrying galaxies and other structures with it. This is known as the metric expansion of space. The expansion rate is described by the Hubble constant, which determines the rate at which galaxies are moving away from each other.

Is the Universe Really Expanding? If So,how Do We Describe