Name: Footnote †: Unstable Equilibrium
Uploaded: 2020-03-28T08:54:17.000Z
Duration: 30 s
Description: Thousands of YouTube videos with English-Chinese subtitles! Now you can learn to understand native speakers, expand your vocabulary, and improve your pronunciation...

As several people have pointed out, a very strong ring around a spherically symmetric

Relative clauses (Restrictive vs. nonrestrictive)

object is in an unstable gravitational equilibrium, which means that if it stays perfectly put,

it’s fine, but if it gets nudged even just slightly off its perfectly centered position,

it will then get pulled farther and farther from that position, since the part now closer

to the earth gets pulled more strongly toward the earth than the part now farther from earth.

So, it’s just like a perfectly balanced pencil.