There is even a long, linked "gallery" list of them available if you go here and use the "Search" function at he top of the page for "bubble"...
It would seem to me that any orb in unconstarined space-time will produce a spherical structure whenever it reaches the point where its internal energy is grater than its cohesion. (IOW, it "explodes"...)
However, I would expect entropy in those sort of events to be headedt he opposite direction of Penrose's supposed new "discoveries". (I don't doubt the discovery of something; I just have seen no evidence and no mathematics applied to it.)