Grace discovers he is not on Earth

After regaining some mobility, Grace performs a simple physics experiment by dropping objects and timing their fall. He calculates the local gravity to be 15 m/s², significantly higher than Earth's 9.8 m/s². This leads him to the shocking conclusion that he is not on Earth, but on a spacecraft experiencing constant acceleration. The realization forces him to confront the possibility that he is far from home, deepening the mystery of his mission and the nature of his surroundings.