Why is the Milky Way flat? - Scott Hershberger
TED-Ed・2 minutes read
The Milky Way galaxy's spiral arms are dynamic structures caused by density waves, evolving over tens or hundreds of millions of years due to overlapping and rotating waves, leading to the reshaping of the galaxy's structure. The Earth is situated on the inner edge of one of these spiral arms within the Milky Way galaxy, which is continually changing and evolving its shape over time.
Insights
- The Milky Way galaxy's flat shape is a result of its high angular momentum, leading to the formation of a spinning disc over billions of years.
- Spiral arms in galaxies, such as the Milky Way, are dynamic structures influenced by density waves that travel through the galaxy, overlapping and rotating at different speeds, breaking apart and reforming over long periods of time.
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Recent questions
What is the Milky Way galaxy?
A massive spiral galaxy containing our solar system.
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Summary
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Evolution of Milky Way Galaxy's Spiral Arms
- The Earth is located on the inner edge of a spiral arm within the Milky Way galaxy, which is constantly evolving and changing its structure over time.
- The Milky Way galaxy's flat shape, unlike stars and planets, is due to its high angular momentum, causing particles to fall parallel to the axis of rotation and form a spinning disc over billions of years.
- Spiral arms in galaxies, like the Milky Way, are dynamic structures caused by density waves traveling through the galaxy, with multiple waves overlapping and rotating at different speeds, eventually breaking apart and re-forming over tens or hundreds of millions of years.
