Domain: Natural Science — Atmospheric Science
Target concept: Smoke from a cigarette rises more rapidly above a warm surface than above a cold surface.

Video generation prompt: A lit incense stick is placed between two identical metal plates, one heated and the other cooled, allowing smoke to rise freely above both.

Evaluation guide:
(i) Target concept: Buoyancy-driven convective flow modulated by surface temperature-induced air density gradients.
Minimum mechanism: Air adjacent to heated plate expands → becomes less dense → exerts greater upward buoyant force on smoke particles; air adjacent to cooled plate contracts → becomes denser → suppresses vertical momentum transfer to smoke, enhancing lateral diffusion and reducing rise rate.
(ii)Storyline: Frame 0–1: Lit incense stick centered; two identical metal plates fully visible side-by-side; thermal indicators (heater/cooler) visibly attached to respective plates. Frame 2–4: Smoke emerges continuously from incense tip; two separate plumes form, one ascending rapidly above heated plate, the other rising sluggishly above cooled plate. Frame 5–8: Height disparity between plumes increases steadily; heated-side plume maintains tight columnar shape; cooled-side plume widens and develops gentle undulations. Frame 9–10: Contrast is maximized and sustained, with no plume collapse, merger, or behavioral reversal; fixed viewpoint captures full vertical development of both plumes without occlusion.

Manual:
Experimental Procedure
1. Place a lit incense stick upright at the center point between two identical horizontal metal plates.
2. Heat one metal plate (e.g., with embedded resistor or hotplate) while actively cooling the other (e.g., with Peltier cooler or chilled base).
3. Record smoke rising freely above both plates simultaneously for 10 seconds.
Observation of Experimental Phenomena
Smoke rises faster, straighter, and higher above the heated plate; smoke rises slower, more diffusely, and terminates lower above the cooled plate—both plumes originate from the same incense tip and remain visually distinct.
Summary of Experimental Principles
Warm air near the heated plate is less dense, creating stronger buoyant force that accelerates smoke ascent; cold air near the cooled plate is denser and resists vertical displacement, resulting in weaker convection and slower, more turbulent smoke rise.

Prompt Grounding rubric:
level_1: No incense stick is present; the two metal plates aren't both visible; there's no sign that one plate is heated and the other cooled; no smoke appears at all; the scene doesn't show a side-by-side comparison setup.
level_2: The incense stick is present and lit, but only one plate is shown; or both plates are shown without any way to tell which is heated and which is cooled (no visible heater/cooler device or indicator); smoke is present but doesn't visibly relate to two separate plate surfaces.
level_3: The lit incense stick sits centered between two identical metal plates, both fully visible and placed symmetrically; at least one visible cue signals which plate is hot and which is cold (e.g., a glowing coil near one, condensation or frost near the other); smoke rises above both.
level_4: All of 3 is met, AND both thermal cues are clearly distinguishable: one plate shows an obvious heating cue (a glowing coil, radiant shimmer, or a visible 'HOT' label) and the other an obvious cooling cue (condensation, frost, or a 'COLD' label); the incense stays centered; smoke leaves the tip and rises above each plate unobstructed.
level_5: All of 4 is met, AND the two plates match each other exactly in size, shape, and finish; the incense stick stays vertically upright and equidistant from both plates; the heating and cooling cues look physically attached to their plates rather than floating separately; the smoke leaves the incense tip continuously and calmly, not turbulently, above each plate, with the whole setup captured in one steady wide shot.

Scientific and Causal Correctness rubric:
level_1: Smoke rises the same way above both plates; or it only rises above one of them; or it sinks or blows sideways instead of rising; or its color and thickness look identical regardless of which plate it's above. There's no visible difference in how it behaves.
level_2: Smoke appears above both plates but behaves basically the same over each: same curve, same height, same density; or the difference runs backwards, rising faster over the cooled plate; or the plume above one plate abruptly vanishes for no physical reason.
level_3: Smoke rises above both plates, and there's a visible difference in how high it gets within the same stretch of time: noticeably taller above one plate than the other; both plumes stay continuous and clearly come from the same incense tip, with no artificial splitting.
level_4: All of 3 is met, AND the plume above the heated plate is consistently straighter, narrower, and climbs higher; the plume above the cooled plate is consistently wider, more wandering, and tops out lower; neither plume shows unnatural bursts of speed, sudden dispersal, or gaps.
level_5: All of 4 is met, AND this contrast holds steady for the whole clip: the heated-side plume stays a tight, coherent column with little sideways spread; the cooled-side plume keeps drifting and spreading sideways while barely gaining height; the two plumes never merge and both still trace back to the same incense tip; at no point does one plume's behavior swap with or match the other's.

Spatiotemporal Consistency rubric:
level_1: The incense stick or either plate jumps to a new position or vanishes and reappears between frames; smoke appears or disappears abruptly with no visible source; the lighting changes erratically; a plate's shape flickers or distorts; the incense tip shifts sideways with no visible path of motion.
level_2: The incense stick or either plate shifts by more than roughly 10% of its on-screen height between consecutive frames with no visible cause; the smoke plume seems to restart or break apart in a way not explained by airflow; a shadow's direction changes even though nothing shown is moving the light source; a plate's surface reflection changes abruptly from one frame to the next.
level_3: The incense stick, once placed, and both plates stay in the same relative positions throughout; the smoke plume develops continuously with no teleporting or frame-skipping look to it; the lighting on the scene stays the same from start to finish; neither plate nor the incense stick warps or changes shape.
level_4: All of 3 is met, AND each smoke plume changes shape and height smoothly across frames with no sudden brightness jumps; there's no visible jitter in the plates' edges or the incense stick's outline frame to frame; no ghosting or motion blur looks out of place given how slowly the smoke is actually drifting.
level_5: All of 4 is met, AND the smoke's rise looks naturally fluid: speeding up and slowing down the way real smoke does rather than moving at one constant speed; the plates' surfaces keep a consistent balance of shine and matte reflection throughout; the incense's ember glows steadily without unrelated flickering; no compression blockiness or shimmering edges appear on any object.