The discussion revolves around how stellar radiation influences the clearing of dust from a proto-planetary disc, transitioning the area from being opaque to transparent. The conversation touches on the mechanisms involved, including radiation pressure and gravitational forces, and explores the implications of these forces on different sizes of objects within the disc.
Participants express varying levels of understanding and curiosity, but there is no explicit consensus on the mechanisms or implications discussed. Multiple viewpoints regarding the effects of radiation on different object sizes remain present.
The discussion does not resolve the complexities of the interactions between radiation pressure and gravitational forces, nor does it clarify the assumptions underlying the scaling arguments presented.
Individuals interested in astronomy, cosmology, and the dynamics of proto-planetary discs may find this discussion relevant.
RJ Emery said:
I'd like to add to the contribution from @Drakkith . You might ask why the radiation affects just the dust and not all the bigger stuff. It's because the area that the radiation acts on an object (and hence the force) is proportional to the radius squared (A = πr2) BUT the gravitational force on an object is proportional to its Mass, which is proportional to the radius cubed. (Mass = density times 4πr3/3). For small objects the radiation pressure wind and for large (massive) objects, the gravitational force wind.RJ Emery said: