Unstable Fluid Podcast 8: Why is Space Flat!?
Jul 1, 2025
Thomas and Kat explore why many celestial objects appear flat, diving into the fascinating world of angular momentum. They discuss how collapsing gas clouds form flat discs, revealing the mechanics behind planetary rings and the intricate dance of moons. The duo also touches on the color intricacies of astronomical images and the surprising true colors of Uranus and Neptune. Plus, they use fun analogies, from figure skating to aerial arts, to explain complex concepts. Join them for a journey through the cosmos!
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Why Rotating Gas Forms Discs
- Angular momentum conservation makes collapsing gas clouds settle into rotating discs instead of spheres.
- As material moves closer it must spin faster, producing a flattened plane where gravity and centripetal forces balance.
Rotation Shapes Planets
- Faster rotation bulges material at the equator and flattens poles, producing oblate shapes like Earth.
- Extremely rapid spin would further flatten a body, limited by structural breakup.
Saturn's Rings From Destroyed Moons
- Thomas recounts how Saturn's many moons and tidal disruption shredded some moons into the thin rings we see today.
- He links ring formation to captured moons and tidal forces tearing them apart into bright, flat rings.