Stephen Hawking was turned on to a problem he had with black hole theory by a Graduate student in the earlier 90's. It involved the problem of entropy in black holes and where the information that went into black holes went when it fell past the event horizon. It seemed strange to them that entropy/information/energy could fall into a black hole and pretty much disappear from the known Universe (if we can never get it back, it can justifiably be said to have disappeared), violating nearly every physical law that we have. As I recall reading about, the mathematics eventually suggested that the information could still exist somehow at the surface of the event horizon, spinning rapidly, and in theory could be retrieved. This gravastar theory sounds like it may have stemmed from some of that research.

It's a good theory.

Nathan