Simplify the following text for a Grade 12 native English-speaking person.
Original: His poetry series Luftskibet ( `` The Airship '' ) was inspired by the balloon flights of fellow physicist and stage magician Ã tienne-Gaspard Robert .
Simplified: His poetry series Luftskibet ( `` Airship '' ) was inspired by the balloon flights of his physicist friend , Ã tienne-Gaspard Robert .