Domain: Natural Science — Atmospheric Science
Target concept: Smog cannot penetrate upward through the warm air layer nor sink downward, and is trapped in the mid-level inversion.

Video generation prompt: A sealed transparent plastic chamber, with a heating plate placed on the top to maintain a layer of warm air and an ice-water bath placed on the bottom to maintain a layer of cold air. Colored smoke is released from the middle of the chamber, and the trajectory of the smoke is recorded.

Evaluation guide:
(i) Target concept: Atmospheric temperature inversion trapping pollutants in a stable mid-level layer.
Minimum mechanism: A stably stratified fluid system where a warmer, less-dense layer overlies a colder, denser layer, creating a vertical barrier to vertical mixing; buoyancy forces prevent smoke particles from crossing the interface.
(ii)Storyline: [Frame 0–2] Chamber fully assembled with heating plate on top and ice-water bath on bottom; smoke source positioned centrally. [Frame 3–4] Colored smoke is released as a coherent plume from midpoint. [Frame 5–8] Plume expands horizontally but halts vertically at distinct upper and lower limits; no particle crosses either boundary. [Frame 9–10] Smoke layer stabilizes into a uniform, motionless horizontal band, fully isolated between warm and cold layers. Perspective: Fixed frontal view showing full chamber height; all critical boundaries (top plate, bottom bath, smoke layer) must remain simultaneously visible and non-occluded.

Manual:
Experimental Procedure
1. Assemble sealed transparent plastic chamber.
2. Place heating plate flush on top exterior surface.
3. Place ice-water bath flush on bottom exterior surface.
4. Release colored smoke from exact vertical midpoint inside chamber.
5. Record smoke trajectory.
Observation of Experimental Phenomena
Colored smoke forms a stable, horizontally confined layer at mid-chamber height—neither rising to contact the warm top layer nor sinking to contact the cold bottom layer.
Summary of Experimental Principles
Smog cannot penetrate upward through the warm air layer nor sink downward, and is trapped in the mid-level inversion.

Prompt Grounding rubric:
level_1: The sealed transparent chamber, the heating plate on top, the ice-water bath on the bottom, and the colored smoke released at mid-height are not shown at all: the video does not depict this chamber setup or any smoke release.
level_2: Only one or two of the required elements appear: for example the chamber is visible but the heating plate is missing, or the smoke is released from the top or bottom rather than the middle, or the plate/bath appear on a side of the chamber rather than its top/bottom, so the top-warm/bottom-cold arrangement is not clearly established.
level_3: The transparent chamber, a heating plate resting on its top, an ice-water bath resting on its bottom, and colored smoke entering at the vertical midpoint are all visible and correctly placed, but the smoke's path is hard to follow because of glare, blur, or low color contrast against the background.
level_4: All elements from the 3-point level are present and correctly placed, and the colored smoke's path is clearly visible for at least about 70% of its travel through the chamber, with the heating plate and ice-water bath remaining in firm contact with the chamber's top and bottom surfaces (not floating or displaced).
level_5: All elements from the 4-point level are present, and the colored smoke's entire path, from its release point at mid-height to wherever it settles, stays clearly visible and high-contrast against the chamber and background for the whole video, with the chamber, heating plate, and ice-water bath never leaving the frame or becoming obscured.

Scientific and Causal Correctness rubric:
level_1: The colored smoke spreads evenly through the whole chamber height, or rises all the way to the heating plate, or sinks all the way to the ice-water bath, showing no sign that a warm-over-cold layering is holding it in the middle.
level_2: The smoke moves only partway toward the top or bottom before the video ends, mixes through most of the chamber's height, or fades out before settling, so there is no visible mid-height band distinguishing it from the warm or cold layer.
level_3: The colored smoke settles into a horizontal band near the middle of the chamber, staying clear of both the heating plate above and the ice-water bath below, but the upper and lower edges of this band waver or blur rather than holding a steady position across the video.
level_4: The colored smoke forms a horizontal band at mid-height with a distinct upper edge that stops short of the heating plate and a distinct lower edge that stops short of the ice-water bath, and this band holds its position for the remainder of the video with no smoke escaping upward or downward.
level_5: The colored smoke forms one uniform horizontal band whose thickness stays constant for the whole video, with no wisp or streak ever crossing above the level implied by the warm top layer or below the level implied by the cold bottom layer at any frame.

Spatiotemporal Consistency rubric:
level_1: The chamber appears to reassemble or relocate partway through the video, the heating plate or ice-water bath jumps to a new position or orientation between frames, the colored smoke appears or disappears with no plume visibly forming or dispersing, or the lighting shifts abruptly between shots with no heat/cold-related cause.
level_2: The heating plate or ice-water bath flickers in and out of view or shifts sideways between frames, or the smoke band jumps to a new height with no visible motion connecting the two positions.
level_3: The chamber, heating plate, and ice-water bath stay in the same place and orientation for the entire video; the colored smoke moves smoothly with no sudden jumps in its position; the chamber walls show no cracks, warps, or breaks appearing partway through.
level_4: All conditions of the 3-point level hold, and in addition the smoke's motion toward its settling band is smooth and gradual rather than jerky or instantaneous, the chamber retains its shape and size with no stretching or distortion, and the viewing angle does not shift or rotate.
level_5: All conditions of the 4-point level hold, and in addition the heating plate and ice-water bath show no visible drift, jitter, or repositioning across the video, the smoke's motion contains no frozen, duplicated, or skipped frames, and the chamber's transparency does not flicker at any point.