Have you ever wondered how trains can levitate and fly at supersonic speeds? One of the core technologies behind this is the principle of electromagnetic acceleration. This is based on the classic law of electromagnetic induction: when an electric current passes through a coil, a strong magnetic field is generated at the center of the coil. If a small metal ball (a good conductor) is placed near this magnetic field, eddy currents will be induced inside the ball, generating a magnetic field opposite in direction to the coil's magnetic field. The two magnetic fields repel (or attract, depending on the coil's polarity), thus exerting a momentary thrust on the ball. The key is precise control: just as the ball is attracted by the magnetic field and is about to reach the center of the coil, the current is immediately cut off. The magnetic field disappears, and the ball continues to move forward due to its inertia. If a series of coils are arranged in sequence and precisely "energized-de-ene
