Spacetime Mirror 

A spacetime mirror is a hypothetical construct in speculative physics and science fiction that reflects not just the three spatial dimensions but also the time dimension. Unlike a standard 3D mirror, which reverses light rays along an axis perpendicular to its surface, a spacetime mirror would reverse along a hyperplane perpendicular to 3+1 spacetime dimensions. The concept serves as a thought experiment to explore the complexities of higher-dimensional spaces and the nature of time.

In the sci-fi novel, the characters used a spacetime mirror to reverse the events of the past and alter the future.

Spacetime Mirror by Phieyl September 5, 2023