Question

If the density of the universe is less than a critical value, thenAnswers:1. it might eventually stop expanding.2. it might continue expanding forever.3. it could expand to a fixed size and remain.4. there's probably less dark matter than luminous.

Answer 1

If the density of the universe is less than the critical density, then the universe will continue expanding forever. This is because gravity is not strong enough to stop the expansion in an open universe.

Step-by-step explanation:

If the density of the universe is less than the critical density, then the universe will continue expanding forever. This is because gravity is not strong enough to stop the expansion in an open universe. This is illustrated by curve 2 in Figure 29.9 and the universe second from the left in Figure 29.8. In an open universe, time and space begin with the Big Bang and have no end.

Answer 2

2. it might continue expanding forever

Step-by-step explanation:

If the ratio is greater than one, then the actual density of the Universe is greater than the critical density, and thus the Universe will eventually become closed and will ultimately end up collapsing in on itself. If the ratio is less than one, then the actual density is less than the critical density, and the Universe is open and expands forever in every direction