Simplify the following text for a Grade 9 native English-speaking person.
Original: Hard science fiction , or `` hard SF '' , is characterized by rigorous attention to accurate detail in quantitative sciences , especially physics , astrophysics , and chemistry , or on accurately depicting worlds that more advanced technology may make possible .
Simplified: These sciences are very important in Hard SF : physics , astrophysics , and chemistry . Also , Hard SF can show worlds that more advanced technology may make possible .