However , if the formation or the delivery of pebbles is slow growth timescales becomes longer than the time required for gravitationally stirring .
This slows their growth relative to their neighbors ( growth becomes oligarchic ) and allows many objects to accrete similar masses of pebbles .
If the formation or the delivery of pebbles is slow growth timescales becomes longer than the time required for gravitationally stirring .
This slows their growth relative to their neighbors ( growth becomes oligarchic ) and allows many objects to accrete similar masses of pebbles .