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>> Also suppose they’re ‘gravitationally bound’. This means their total energy, kinetic and potential, is negative. That means they couldn’t all shoot off to in
by phkahler 2y ago
>> Also suppose they’re ‘gravitationally bound’. This means their total energy, kinetic and potential, is negative. That means they couldn’t all shoot off to infinity even if the sphere wasn’t there holding them in.
This seems like an invalid assumption. We know that clusters of stars can eject some of their members. Lot of hand waving in this one.
- ISL 2y agoThat's only an initial condition -- that requirement states only that the total energy is negative. We are gravitationally bound to Earth, but the Voyagers have left the solar system.
- pavel_lishin 2y agoThat sentence does say "couldn't all shoot off to infinity".