A Jacob’s ladder is a high-voltage electrical device that creates a continuous arc which appears to “climb” upward between two diverging metal rods. While it looks almost alive, the motion is governed by a combination of plasma physics, electric fields, and fluid dynamics. When a sufficiently high voltage is applied across the rods, the electric field becomes strong enough to ionize the air at the smallest gap near the bottom. Ionization means neutral air molecules lose electrons, forming a conductive plasma. This allows current to flow, creating a bright, hot electric arc. As current passes through the plasma, it rapidly heats the surrounding air. Hot air is less dense than cooler air, so it rises due to buoyancy. The arc, being embedded in this rising column of hot ionized gas, is carried upward. At the same time, the rods are angled apart. As the arc rises, the distance between the rods increases. Eventually, the gap becomes too large for the voltage to sustain the plasma, causin...