Dark Matter - 15a - Intro to Astronomy Sessions

There is consistent disagreement between the amount of visible matter that we can see in galaxies and galaxy clusters, and the motions of these objects. Is there a misunderstanding in how gravity works on these scales? Or are we observing the gravitational effects of an as yet unidentified and invisible type of matter? In this video we discuss some of the ideas and evidence around this dark matter model.
Full Series Playlist: • Intro to Astronomy Ses...
Please note that this was designed as an introductory survey of astronomy course, mostly for non-science majors, and does simplify many of the topics accordingly. I encourage people who are just getting into astronomy to use this as a jumping off point for more in depth studies. I've tried to edit out specific references to my course (regarding assignments, tests, etc.) but I might have missed some. Finally, scientific fields are constantly advancing, with new data and studies resulting in our ideas being continually improved. This means some of the ideas presented here may soon be out of date, so I again encourage people to continue to investigate whichever topics are of particular interest to you.
Opening Image Credit: www.nasa.gov/feature/goddard/...