Final answer:
The universe is most likely to continue expanding indefinitely, driven by dark energy. The observed acceleration of the universe's expansion supports this conclusion. A big crunch or collapse is unlikely to happen.
Step-by-step explanation:
The universe is most likely to continue to expand indefinitely. This conclusion is supported by the observed acceleration of the universe's expansion and the discovery of dark energy.
Dark energy is causing the rate of expansion to speed up, making it unlikely for the universe to experience a big crunch or collapse upon itself. As the universe continues to expand, clusters of galaxies will spread farther apart, resulting in a thinner, colder, and darker universe over time.