Starship Asterisk*

To the OP - you also have several scales/regimes during planet formation, some where the rocky bits are tiny and coupled to the gas flow, some where they are influenced by it, and some where they influence it. When you start talking about regimes where the dynamics are controlled by collisions of la...

Its true that most of the angular momentum in the solar system is in the planets (mostly Jupiter). Its also true that magnetic fields and plasma effects are a dominant driver of angular momentum transport and other dynamics in most accretion disks. Its implausible that the magnetic fields played the...

Oh yes, I think the eddy formalism you are talking about is based in the fluid mechanical notion that a fluid element displaced from its location in a keplerian shear flow will exhibit retrograde epicyclic motion. This doesn't take into account local gravitational 'kicks' from material accreting ont...

Bear in mind the following is not the only way this can happen, it is just a physically intuitive way to explain. OK, the easy answer is conservation of angular momentum or spin/orbit direction. A huge cloud of gas that rotates about some central axis collapses into a disk as it is gravitationally c...