Question 1:

What is the expansion of the universe?

Explanation: The expansion of the universe refers to the increase in the distance between galaxies over time.

Question 2:

What is Hubble's law?

Explanation: Hubble's law is a fundamental principle in cosmology that describes the expansion of the universe and the relationship between the recessional velocity of galaxies and their distance from us.

Question 3:

What is the Hubble constant?

Explanation: The Hubble constant is the rate at which the universe is expanding, describing the relationship between the recessional velocity of galaxies and their distance.

Question 4:

What is the cosmic microwave background radiation?

Explanation: The cosmic microwave background radiation is the radiation left over from the early universe, which provides evidence for the Big Bang theory and the expansion of the universe.

Question 5:

What is redshift?

Explanation: Redshift is the shifting of light towards longer wavelengths, indicating that galaxies are moving away from us and providing evidence for the expansion of the universe.