Teacher: In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
Teacher: Now, understand the problem? If you are still confused, see the following example:
The Inheritance Cycle is a series of fantasy books written by Christopher Paolini.
Solution: The Inheritance Cycle is a tetralogy of young adult high fantasy novels written by American author Christopher Paolini.
Reason: The output sentence elaborates on the input sentence without changing its general meaning e.g. "tetralogy of young adult high fantasy novels".

Now, solve this instance: More importantly , the discovery of celestial bodies orbiting something other than the Earth dealt a blow to the then-accepted Ptolemaic world system .
Student:
More importantly , the discovery of celestial bodies orbiting something other than Earth dealt a blow to the then-accepted Ptolemaic world system , which held that Earth was at the center of the universe and all other celestial bodies revolved around it .