Question

What is one thing scientists have learned about the universe by observing supernovas? (Paragraphs 6-8)

A) It is expanding at an increasing rate.
B) It is expanding at a decreasing rate.
C) It is almost finished expanding.
D) It is made of few elements.

Answer 1

Scientists have observed that the universe is expanding at an increasing rate by studying supernovas, leading to the concept of dark energy.

Step-by-step explanation:

Scientists have learned that the universe is expanding at an accelerating rate by observing supernovas. The light from these supernovas, which are essentially exploding stars, has to travel farther and appears fainter than expected if the expansion rate were constant. This discovery was initially resisted by astronomers because it was so unexpected and contradicted the notion that the universe's expansion was slowing down due to gravity. The acceleration suggests the presence of a force or property in the universe not accounted for by existing physical theories, often attributed to dark energy.