Author Question: If the carbon isotope evidence does indicate life 3.85 billion years ago, it suggests that life must ... (Read 78 times)

sheilaspns · **on:** Jul 27, 2018

If the carbon isotope evidence does indicate life 3.85 billion years ago, it suggests that life must have been widespread at that point.

Indicate whether the statement is true or false

Question 2

Explain why we observe distant galaxies to be moving away from us and therefore believe that the universe is expanding, but we don't see individual galaxies or clusters expanding.

What will be an ideal response?

scrocafella · **Reply #1 on:** Jul 27, 2018

Answer to Question 1

TRUE

Answer to Question 2

The pull of gravity works to slow the expansion rate of the universe. Therefore, in dense regions such as galaxies and clusters of galaxies, gravity is able to overcome the expansion and keep these objects from expanding. However, on larger scales, where the average density is lower, gravity does not have as strong an effect, and therefore the expansion continues between clusters of galaxies.