# Dark matter: How does it explain a star's speed?

- Institution: TED
- Department: TED-Ed
- Speaker: Don Lincoln
- Year: 2012
- Level: For everyone
- Language: English
- Subjects: Astronomy and space, Teaching and learning
- Source: [TED](https://www.ted.com/talks/don_lincoln_dark_matter_how_does_it_explain_a_star_s_speed)
- Licence: [CC BY-NC-ND 4.0](https://creativecommons.org/licenses/by-nc-nd/4.0/) (Non-commercial use only, and no changed versions.)
- Who can watch: Tweens profiles and older (sources give no ratings; placed by Invisible Network from the source's own words)

All the stars in a spiral galaxy rotate around a center — but to astronomers, the speed that each star travels wasn't making sense. Why didn't stars slow down toward the edges as expected? Don Lincoln explains how a mysterious force called dark matter is (possibly) the answer — and why the search for an answer matters. \[Directed by Gatze Zonneveld, narrated by Don Lincoln\].

## Lectures

1. [Dark matter: How does it explain a star's speed?](https://invisiblenetwork.ai/learn/ted/don_lincoln_dark_matter_how_does_it_explain_a_star_s_speed/5378ca6d1260), 3 min (TED's player)