AY 101 Chapter Notes - Chapter 18: Cosmic Microwave Background, Dark Matter, Dim Stars

• School: University of Alabama
• Department: Astronomy
• Course: AY 101
• Professor: Raymond White

Document Summary

We have found that there may be much more to the universe than meets the eye. Dark matter too dim for us to see seems to far outweigh the stars, and a mysterious dark energy may be even more prevalent. Together, dark matter and dark energy have probably been the dominant agents of change in the overall history of the universe. Here are some key big picture points to remember about this chapter: dark matter and dark energy sound very similar, but they are hypothesized to explain different observations. Dark matter is thought to exist because we detect its gravitational in uence. Dark energy is a term given to the source of the force that is accelerating the expansion of the universe: either dark matter exists or we do not understand how gravity operates across galaxy-size distances. Nevertheless, forever is a long time, and only time will tell whether new discoveries will alter our speculations about the distant future.