Domain: Natural Science — Physics
Target concept: Infrared lamps heat the black and white surfaces, causing the wax to melt.

Video generation prompt: Two identical metal plates are placed side by side, one painted matte black and the other matte white, with wax particles placed on top, under an infrared lamp; the lamp is turned on and the process is recorded.

Evaluation guide:
(i) Target concept: Differential infrared absorption by surface color drives unequal thermal energy transfer to wax.
Minimum mechanism: Infrared lamp emits non-visible radiant energy; matte black surface has higher absorptivity (→ higher emissivity in same band) than matte white; absorbed energy converts to heat; wax melting point (~45–60°C) is exceeded first where heat flux is greatest.
(ii)Storyline: [Frame 0] Static wide shot: two side-by-side metal plates, one matte black, one matte white, each topped with discrete wax particles; infrared lamp off but visible above center. [Frame 1–3] Lamp activates (visible glow/intensity increase); no wax change yet. [Frame 4–7] Wax on black plate begins losing particle definition (edges soften, coalescence starts); wax on white plate remains fully granular and distinct. [Frame 8–10] Black-plate wax shows clear liquid features (droplets, pooling, loss of individuality); white-plate wax retains solid particle morphology. Perspective: fixed frontal view, no camera movement, full plates and lamp in frame at all times; no occlusions.

Manual:
Experimental Procedure
1. Place two identical bare metal plates side-by-side on a stable surface.
2. Paint one plate matte black, the other matte white.
3. Evenly scatter identical wax particles on top of both plates.
4. Position an infrared lamp directly above both plates.
5. Turn on the lamp and record for 10 seconds.
Observation of Experimental Phenomena
Wax particles on the matte black plate begin melting visibly earlier and more extensively than those on the matte white plate.
Summary of Experimental Principles
Matte black surfaces absorb more infrared radiation than matte white surfaces, converting it to heat; this causes greater temperature rise and faster wax melting on the black plate.

Prompt Grounding rubric:
level_1: No infrared lamp is visible anywhere in the frame; or fewer than two metal plates appear; or no wax particles are visible on either plate; or the two plates cannot be told apart as one darker/black-painted surface and one lighter/white-painted surface.
level_2: An infrared lamp and at least one metal plate are visible, but only one plate appears on screen, or the two plates' colors cannot be distinguished as matte black versus matte white, or no wax particles are visible on the plate(s) shown, or the two plates are stacked or overlapping rather than placed next to each other.
level_3: An infrared lamp is visible above the setup; two metal plates are shown next to each other, one clearly matte black and the other clearly matte white; wax particles are visibly scattered on top of both plates; and the lamp is shown switching on or is already glowing/active.
level_4: An infrared lamp is visible above two side-by-side metal plates, one clearly matte black and the other clearly matte white, each with wax particles scattered on top; the lamp is shown switching on or already active; the wax on both plates is visibly still solid, discrete particles at the very start of the clip; and no hands, labels, or on-screen text ever enter the shot.
level_5: An infrared lamp is centered above two side-by-side metal plates, one clearly matte black and the other clearly matte white, each starting with visibly solid, discrete wax particles; the lamp is shown switching on or already active with illumination reaching both plates similarly; the two plates occupy roughly equal area in the frame with a visually similar number and layout of wax particles on each; no hands, labels, or text ever enter the shot; and the camera does not pan, zoom, or cut for the entire clip.

Scientific and Causal Correctness rubric:
level_1: Neither plate's wax shows any melting during the clip, or the wax on both plates melts in a visually identical way with no distinguishable difference between the black and white plates.
level_2: Wax melts on both plates, but either the white-plate wax melts as fast as or visibly faster than the black-plate wax, or any melting shown begins before the lamp is ever shown switched on, so the melting cannot be attributed to the lamp's heating action.
level_3: After the lamp is shown switched on, the wax on the black plate is the first to show visible softening or shape change (edges rounding, particles losing their sharp outline), and the wax on the white plate stays visibly solid and granular for a noticeably longer stretch of the clip; no melting on either plate begins before the lamp's activation is visible.
level_4: After the lamp is shown switched on, the black-plate wax is consistently the first to soften and begins showing liquid features (pooling, merging droplets, loss of individual particle shape) before the white-plate wax does; the white-plate wax remains visibly more solid than the black-plate wax at every later point in the clip; and the black-plate wax's melting advances steadily with no sudden all-at-once jump from solid to fully liquid and no re-hardening.
level_5: After the lamp is shown switched on, the black-plate wax visibly melts first and stays more melted than the white-plate wax at every point afterward, progressing smoothly from distinct solid particles to pooled liquid with no re-solidification, no charring or smoke, and no wax spilling past the plate's edge; the white-plate wax stays recognizably more solid and granular than the black-plate wax for the entire remainder of the clip, giving an unambiguous, sustained contrast between the two plates.

Spatiotemporal Consistency rubric:
level_1: One of the two plates is in a noticeably different spot than in the previous frame with no motion shown getting it there; a wax particle blinks out of existence or appears out of nowhere with no motion carrying it; the lamp switches from fully off to fully lit (or the reverse) within a single frame with no transition; or a plate's edge visibly tears or bends between frames.
level_2: A plate visibly slides sideways or rotates by more than about 10% relative to the frame between one frame and the next while the rest of the scene stays still; wax particles jitter erratically or drift upward on their own; the lamp's brightness flickers unevenly in a way unrelated to it being switched on; or the shadows cast by the plates point a different way than before with no lamp or camera movement shown to explain it.
level_3: The two plates stay in the same positions and spacing next to each other throughout the clip; the wax particles stay on their own plate without sliding off or floating away; the lamp stays fixed in place above the plates; and the lighting stays steady in direction and brightness apart from the expected brightening when the lamp switches on.
level_4: The two plates, the wax particles on each, and the lamp all stay in the same spots relative to one another for the whole clip; the melting wax's motion (softening, merging, dripping) looks smooth and physically plausible with no stutter or sudden jumps; and no part of a plate or its wax is ever oddly hidden or revealed without something moving to explain it.
level_5: The two plates, the wax on each, and the lamp keep exactly the same layout relative to one another for the entire clip with no drift, rotation, or resizing; the melting wax on the black plate moves smoothly from solid particles to pooled liquid with no freezing or skipped motion; the shadows and highlights only change in step with the lamp switching on, never abruptly; and the two plates never appear to warp or change size relative to each other.