Domain: Natural Science — Physics
Target concept: Differential rotational inertia (fluid-shell decoupling), rapid stop of a raw egg's rotation

Video generation prompt: Place two eggs of the same size side by side on a table, with the left egg being a raw egg and the right egg being a boiled egg. Rotate both eggs simultaneously on the table with the same amount of force.

Evaluation guide:
(i) Target concept: Differential rotational inertia between fluid-filled (raw) and solid (boiled) ovoid (egg-shaped) bodies under transient torque.
Minimum mechanism: Raw egg must contain mobile internal mass (liquid albumen/yolk) that decouples from shell motion upon torque cessation; boiled egg must behave as a homogeneous solid with coupled mass distribution.
(ii)Storyline: Frame 1–2: Eggs placed side-by-side, static, labeled/visually distinct. Frame 3–4: Hands contact both eggs simultaneously. Frame 5–6: Both eggs begin synchronous rotation on table surface. Frame 7–8: Rotation peaks, then external force ceases. Frame 9–10: Raw egg halts rapidly and wobbles; boiled egg sustains rotation visibly longer and stops smoothly. All events occur from fixed frontal viewpoint with full visibility, no occlusion, and continuous spatiotemporal flow.

Manual:
Experimental Procedure
1. Place one raw egg and one boiled egg of identical size side-by-side on a flat horizontal table — raw on left, boiled on right.
2. Simultaneously rotate both eggs on the table surface around their long axes using equal manual force.
Observation of Experimental Phenomena
The raw egg stops rotating quickly after force ends and exhibits a brief visible wobble. The boiled egg continues rotating noticeably longer and stops smoothly without wobble.
Summary of Experimental Principles
The raw egg's liquid interior is only loosely coupled to its shell, so when an external hand decelerates the shell, the liquid keeps moving under its own rotational inertia; the resulting drag between the still-moving fluid and the shell causes rapid shell deceleration and produces the post-stop wobble. The solid boiled egg rotates as a single rigid body — shell and interior share one angular momentum — so it sustains rotation longer with no internal lag.

Prompt Grounding rubric:
level_1: No two eggs present; or only one egg visible; or eggs not side-by-side on a flat horizontal surface; or no rotation action shown; or rotation applied to only one egg; or eggs visibly different in size/shape.
level_2: Two eggs present and side-by-side on table, but at least one of: eggs not same apparent size/shape; rotation not initiated simultaneously on both; rotation applied with visibly unequal force (e.g., one egg spun with finger flick, other with palm press); or eggs not both rotating on their long axis on the table surface.
level_3: Two eggs of identical apparent size and shape placed side-by-side on a flat horizontal table surface; both eggs begin rotating simultaneously on the table surface around their long axes; rotation is initiated by direct manual contact (e.g., fingers) on each egg; no other objects or hands obscuring eggs during rotation onset.
level_4: All conditions for score 3 met; additionally: both eggs remain fully visible and unobscured throughout entire rotation phase; spatial arrangement (left raw, right boiled) is stable and unambiguous from fixed frontal viewpoint; no extraneous motion (e.g., sliding, wobbling off-axis) dominates initial rotation.
level_5: All conditions for score 4 met; additionally: left egg is visually identifiable as raw (e.g., subtle translucency, faint yolk shadow, or labeled “raw”, but label must be consistent, non-distracting, and co-located with egg); right egg is visually identifiable as boiled (e.g., opaque, matte surface, or labeled “boiled”; same labeling constraints); labels (if used) are present from first frame of placement and persist without flicker or occlusion.

Scientific and Causal Correctness rubric:
level_1: No discernible difference in rotational behavior between eggs; or both eggs stop instantly after force ceases; or raw egg stops *before* boiled egg; or boiled egg continues spinning significantly longer but raw egg shows no residual internal motion (e.g., no wobble, no secondary sway after spin stops).
level_2: Eggs show differential stopping behavior, but causal direction is inverted or absent: e.g., raw egg spins longer than boiled egg; or both eggs stop at same time with no observable internal lag; or raw egg stops abruptly *and* shows no post-stop wobble while boiled egg exhibits sustained spin.
level_3: Raw egg (left) stops rotating quickly after external force ends; boiled egg (right) continues rotating for visibly longer duration; raw egg exhibits brief but clearly visible wobble or secondary sway *after* main rotation stops; boiled egg comes to rest smoothly without wobble.
level_4: All conditions for score 3 met; additionally: wobble of raw egg occurs *only after* its primary rotation has fully ceased (no overlap); boiled egg’s continued rotation is continuous and uninterrupted (no stutter, jerk, or pause); no reversal or backward motion observed in either egg.
level_5: All conditions for score 4 met; additionally: raw egg’s wobble is exclusively vertical-axis–aligned (no lateral translation or sliding); boiled egg’s extended rotation maintains consistent axis alignment and steady angular motion (no precession or tumbling); wobble amplitude and duration are moderate and physically plausible, neither frozen nor exaggerated beyond natural fluid inertia effects.

Spatiotemporal Consistency rubric:
level_1: Severe spatiotemporal violations: eggs teleport between frames; sudden disappearance/reappearance; abrupt scale/rotation angle jumps >90° between consecutive frames; lighting changes discontinuously (e.g., full shadow → full highlight in one frame); table surface deforms or breaks continuity.
level_2: Moderate violations: eggs shift laterally >1/2 egg width between frames without sliding motion; rotation starts/stops with frame-skipping or stutter (≥2 frames frozen mid-motion); hand enters/exits inconsistently (e.g., appears mid-air without entry trajectory); shadow disconnects from egg base for ≥3 consecutive frames.
level_3: Minor but detectable violations: slight jitter in egg position during rotation (no more than 1/4 egg width per frame); brief hand occlusion of egg top for ≤2 consecutive frames during initiation; smooth but slightly uneven rotation speed (no reversal or jump); shadows remain attached and consistent in orientation.
level_4: All conditions for score 3 met; additionally: no frame-level discontinuities in egg contour, edge definition, or surface texture; no visible rendering artifacts (e.g., aliasing, ghosting, warping); motion trajectories are physically coherent: no floating, no penetration into table surface; hand motion follows natural biomechanical path during spin initiation.
level_5: All conditions for score 4 met; additionally: inter-frame motion is perfectly smooth with zero pixel-level strobing or micro-judder; all object boundaries remain crisp and temporally stable; table surface reflects consistent ambient lighting with no temporal inconsistency in highlight/shadow placement; no depth distortion (e.g., eggs retain consistent relative size and perspective across motion).