Domain: Natural Science — Physics
Target concept: Magnetic force hinders the motion of an object

Video generation prompt: A aluminum rod is placed on the left side of the table, and a plastic rod of the same height is placed on the right side. A strong magnet ring is slipped over the left aluminum rod, and an iron ring is slipped over the right plastic rod. Both rings are released from the same height simultaneously.

Evaluation guide:
(i) Target concept: Electromagnetic damping via eddy currents in a non-ferromagnetic conductor (aluminum) hinders motion of a moving magnet, whereas a ferromagnetic ring (iron) on a non-magnetic insulator (plastic) experiences no such damping and falls freely.
Minimum mechanism: Aluminum must be electrically conductive and non-ferromagnetic; magnet must be moving relative to aluminum to induce eddy currents; plastic must be electrically insulating and non-magnetic; iron must be ferromagnetic but here acts only as a passive mass; its fall confirms absence of magnetic coupling to plastic.
(ii)Storyline: Frame 0–1: Static setup visible: aluminum rod (left), plastic rod (right), magnet ring seated on aluminum, iron ring seated on plastic, both rings aligned at same height. Frame 2–3: Simultaneous release cue (e.g., fingers retracting or clear onset of motion). Frame 4–10: Iron ring descends continuously along plastic rod axis; magnet ring's descent is dramatically slowed by eddy-current drag, creeping down almost imperceptibly (no bounce, no tilt, no abrupt stop). Viewpoint is fixed frontal shot capturing full side-by-side composition; lighting is uniform and static; no occlusion; all causal transitions are directly visible and temporally contiguous.

Manual:
Experimental Procedure
1. Place upright aluminum rod on left side of table.
2. Place upright plastic rod of same height on right side of table.
3. Slip strong magnet ring onto aluminum rod.
4. Slip iron ring onto plastic rod.
5. Release both rings from same height simultaneously.
Observation of Experimental Phenomena
The magnet ring's fall down the aluminum rod is dramatically slowed by eddy-current drag, so it creeps downward only a barely perceptible amount over the course of the video; the iron ring falls continuously and freely down the plastic rod to the table.
Summary of Experimental Principles
As the magnet ring moves relative to the electrically conductive, non-ferromagnetic aluminum rod, it induces eddy currents whose magnetic field opposes the ring's motion (Lenz's law), producing a velocity-dependent drag that dramatically slows its descent. Because this drag force shrinks as the ring's speed drops, it can slow the fall to a near-standstill but not bring it to a literal permanent stop. The plastic rod is an electrical insulator, so it cannot support eddy currents; the iron ring, though ferromagnetic, has no magnet or moving conductor to couple with on the plastic rod, so it simply falls freely under gravity.

Prompt Grounding rubric:
level_1: The aluminum rod or the plastic rod is missing; or the magnet ring or the iron ring is missing; or the rods are not placed with aluminum on the left and plastic on the right; or the magnet ring is not slipped onto the aluminum rod (or the iron ring is not slipped onto the plastic rod); or the two rings are not released from the same height at the same time; or only one rod/ring pair appears on screen.
level_2: Both rods and both rings appear, but the arrangement is wrong: e.g., the aluminum and plastic rods are on the same side, or the magnet ring sits on the plastic rod while the iron ring sits on the aluminum rod, or one ring clearly begins falling well before the other with no overlapping motion.
level_3: Aluminum rod stands on the left, plastic rod on the right; the magnet ring is fully slipped onto the aluminum rod and the iron ring is fully slipped onto the plastic rod; both rings are released from the same starting height and begin moving within the same frame or immediately adjacent frames.
level_4: Everything required at the 3-point level holds, and in addition: the aluminum and plastic rods are visually the same height (no obvious taller/shorter mismatch); the magnet ring and iron ring are visually the same outer diameter; the camera holds a fixed, front-facing framing that keeps both rods and both rings fully in view without cropping.
level_5: Everything required at the 4-point level holds, and in addition: both rods stay vertically upright without tilting, wobbling, or sliding on the tabletop during release; each ring stays centered on its own rod's axis throughout the descent, without slipping sideways off the rod or spinning in a way that hides which ring is which; neither ring nor rod disappears from frame, duplicates, or shows an obvious digital overlay artifact.

Scientific and Causal Correctness rubric:
level_1: No difference in falling behavior is visible between the two rings: e.g., the magnet ring falls down the aluminum rod just as fast as the iron ring falls down the plastic rod, or the iron ring stalls/hovers mid-air, or the magnet ring is stuck rigidly to the rod with absolutely no relation to gravity (e.g., held at an angle or floating off-axis).
level_2: The magnet ring does descend noticeably (more than a slight creep) while the iron ring also descends, but the two speeds look similar or only mildly different; the sharp contrast between a heavily damped magnet ring and a freely falling iron ring is not evident.
level_3: The magnet ring on the aluminum rod descends far more slowly than the iron ring on the plastic rod: over the visible duration the magnet ring moves down only a small fraction of the rod's length while the iron ring falls continuously to the table (or out of frame); this speed contrast is clear and unambiguous.
level_4: Everything required at the 3-point level holds, and in addition: the magnet ring's descent looks like a slow, steady creep (no sudden bounce, no upward rebound, no brief sideways slip), while the iron ring's fall is uninterrupted from release to impact with no pause or hesitation; the magnet ring shows no sign of being pulled sideways toward the rod.
level_5: Everything required at the 4-point level holds, and in addition: the magnet ring's slow creep is essentially the only motion it shows (no extra shimmer, shake, or jitter beyond that slow descent), while the iron ring keeps a steady, flat orientation as it falls; nothing in the video (glow, smoke, discoloration) implies eddy-current heating: only the mechanical contrast between damped and undamped fall is shown.

Spatiotemporal Consistency rubric:
level_1: The aluminum rod, plastic rod, magnet ring, or iron ring vanishes and reappears at a different spot with no visible path between; or the screen flashes to black or suddenly changes brightness for more than an instant; or the framing jumps to a different zoom/crop without transition; or a rod snaps or a ring cracks apart with no physical cause.
level_2: No outright vanishing or scene cut, but one of the objects flickers in and out of visibility frame to frame; or the shadows cast by the rods/rings swing to a new direction with no corresponding change in the light source; or a rod's base visibly skids sideways along the tabletop during release; or a ring spins so fast its ring shape is lost.
level_3: The aluminum rod, plastic rod, magnet ring, and iron ring each keep a steady position, size, and orientation relative to the tabletop; nothing teleports, breaks apart, or flickers; the iron ring's fall traces a straight vertical path down the plastic rod rather than veering sideways or diagonally.
level_4: Everything required at the 3-point level holds, and in addition: the tabletop stays flat and rigid with no warping or rippling; both rod bases stay planted on the table throughout; both rings keep a consistent ring-shaped silhouette while moving (no stretching, squashing, or morphing); the iron ring never appears to pass through the plastic rod.
level_5: Everything required at the 4-point level holds, and in addition: the camera holds its framing with no drift, pan, or roll that would shift the rods' apparent positions; the shadows cast by the rods and rings keep the same direction and softness from the first frame to the last; the iron ring's fall and the magnet ring's slow creep both play back smoothly, with no stutter, skipped frames, or repeated frames.