Domain: Natural Science — Marine Science
Target concept: Sea Water Evaporation and Salt Crystallization

Video generation prompt: Pour a suitable volume of natural seawater into a transparent evaporation dish, and place it in a constant-temperature, well-ventilated environment, recording the dish continuously over time as the water level changes.

Evaluation guide:
(i) Target concept: Evaporative concentration-driven phase transition from aqueous solution to solid crystalline phase.
Minimum mechanism: Seawater must be a stable, homogeneous aqueous solution containing dissolved NaCl; evaporation must occur under passive, non-boiling conditions; crystallization must follow supersaturation and nucleation at solid–liquid interface.
(ii)Storyline: Frame 1–2: Seawater poured into transparent dish → Frame 3–5: Dish stationary, liquid surface intact, ambient lighting stable → Frame 6–8: Meniscus visibly lowers, surface area shrinks → Frame 9–10: First crystalline solids appear at dish bottom periphery; no crystals in bulk liquid or on dish walls above liquid line. Perspective: Fixed frontal/slightly oblique view, dish centered, full dish in frame, no occlusion, consistent focus plane across all frames.

Manual:
Experimental Procedure
1. Pour natural seawater into a transparent evaporation dish until liquid covers bottom uniformly.
2. Place dish in constant-temperature, well-ventilated location.
3. Record time-lapse video capturing liquid level decrease and solid formation.
Observation of Experimental Phenomena
- Liquid volume visibly decreases over time.
- White or translucent cubic/irregular crystalline solids precipitate on dish bottom and edges.
- Crystals appear only after significant liquid reduction; no floating or suspended solids.
Summary of Experimental Principles
- Sea water evaporation concentrates dissolved ions (Na⁺, Cl⁻).
- When solubility limit is exceeded, NaCl crystallizes as solid salt — salt crystallization.

Prompt Grounding rubric:
level_1: No seawater is shown, no evaporation dish appears, no pouring or placement action occurs, and the scene bears no visible relation to the posted_prompt (e.g., an empty benchtop, a different liquid, or an unrelated container).
level_2: A transparent dish or a liquid is shown but not both together as described: e.g., the dish is empty when placed, or liquid is poured into an opaque or non-dish container; the pouring action and settled placement are missing or shown out of order (e.g., the dish already sits with liquid before any pour is seen).
level_3: Seawater is visibly poured into a transparent evaporation dish; the dish is then set down in a stationary position; successive frames show the dish undisturbed with no wind-blown ripples, splashing, or added liquid; the pour, placement, and settling occur in that order.
level_4: All elements of score 3 are present AND the dish stays transparent and centered in frame for the full sequence, the poured seawater covers the dish bottom without overflowing the rim, and the pour-to-placement motion is a single unbroken action with no cut to a different angle or a repositioned dish.
level_5: All elements of score 4 are present AND the camera viewpoint, dish scale, and framing stay identical from the first frame to the last; no extra object (hand, tool, second dish) enters or leaves the shot after placement; there is no jump cut, duplicated frame, or overlay interrupting the recording.

Scientific and Causal Correctness rubric:
level_1: The dish shows no plausible physical process: e.g., crystals appear with the liquid volume unchanged, the seawater vanishes leaving no residue at all, or the solid that appears is a fine white powder or amorphous smear rather than granular, faceted salt deposits; the liquid itself turns a color seawater cannot show (blue, green, or opaque white).
level_2: The liquid is present but shows no sign of evaporating (the meniscus never drops, the wetted area never shrinks) and no solid ever appears; alternatively, a deposit appears but reads as sludge, dust, or scattered debris rather than crystalline salt, so the pour-evaporate-concentrate-crystallize chain is never visible.
level_3: The liquid level visibly drops across the sequence; small white-to-translucent crystalline grains appear at the dish bottom or along its rim only in the later frames, forming an irregular, clustered deposit consistent with salt left behind as seawater dries; the sequence liquid-present -> liquid-reduced -> crystals-emerge is visible.
level_4: All elements of score 3 are present AND crystals appear only after the liquid level has visibly dropped (never while the dish is still full); the crystals stay at the dish bottom and rim rather than floating in the remaining liquid; the remaining liquid shows no gel-like film, no bubbling, and at most a faint straw-yellow tint from dissolved organics rather than any stronger color shift.
level_5: All elements of score 4 are present AND the crystal clusters visibly enlarge outward from their original spots rather than appearing suddenly in new locations; the remaining liquid keeps a clear-to-pale-straw seawater appearance and never turns milky or opaque; no crystal dissolves or re-liquefies once formed; the crystals show the angular, faceted look of halite rather than rounded, thread-like, or branching shapes.

Spatiotemporal Consistency rubric:
level_1: Severe breaks in continuity: the dish or liquid disappears and reappears between frames, the liquid level jumps between two different heights with no pour or evaporation shown bridging them, crystals blink in and out of existence, the lighting swings between bright and dark within a couple of frames, or the benchtop/background geometry warps.
level_2: Noticeable but less severe problems: the dish shifts position or rotates by a large, visible amount (more than about 10% of the frame width) between frames; the liquid surface flickers on and off inconsistently; the shadow cast by the dish swings to a different direction partway through the sequence; or the frame rate visibly stutters.
level_3: Small, one-off glitches are tolerable: e.g., a single frame shows condensation on the dish rim not present just before or after, or one frame is briefly overexposed near the crystals, but apart from that isolated moment, the dish position, the light's direction, and the liquid surface all stay visibly stable and physically sensible.
level_4: All elements of score 3 are satisfied AND the dish never stretches, warps, or gets unnaturally occluded; the liquid surface stays flat and level throughout; once crystals form they stay in the same spot on the dish floor rather than sliding around; the light's brightness and direction stay the same from first frame to last.
level_5: All elements of score 4 are satisfied AND the dish rim traces the same outline in every frame; the liquid's meniscus curves smoothly and shrinks in one consistent direction without reversing; the crystal clusters only ever add area at their edges rather than being replaced or erased between frames; there is no motion blur inconsistent with a dish that never moves, and no sense of the camera drifting or panning.