Richard Feynman's Magnetic Personality...

 from Google AI:

Magnetism and its underlying laws allow for the simulation of time moving backwards at a quantum or wave level. While thermodynamic time moves forward, manipulating spin dynamics with magnetic fields can make quantum systems, such as nuclear spins in molecules, appear to reverse their evolution. Specific experiments using magnetic fields can force particles to behave as if time is reversed, such as reversing the direction of magnetic fields and particle currents. 

Key Concepts in Magnetic Time Reversal: 

Quantum Spin Reversal: Researchers have used strong magnetic fields to manipulate the spin of particles (like in chloroform molecules), forcing them to evolve back to their original state, effectively reversing the thermodynamic arrow of time. 

Electromagnetic Time Reversal: Scientists have demonstrated that electromagnetic waves can be reversed in time by creating "time interfaces" using metamaterials with high-speed switches, essentially acting as a "time mirror". 

Time-Reversal Invariance: The fundamental laws of electromagnetism are generally time-reversal invariant, meaning the equations work the same forward or backward, allowing for theoretical reversal of physical processes. 

Limitations: While these experiments create conditions where time appears to move backward for specific particles or waves, they do not constitute reversing the overall flow of time for the universe. 

Geomagnetic Reversal: Earth's magnetic poles periodically swap (north to south), which is a "reversal" of the field, but this is a physical flip of the magnetic field over thousands of years, not a reversal of time itself.