Domain: Engineering — Civil & Environmental Engineering
Target concept: Food dyes are adsorbed onto activated carbon or soil in water.

Video generation prompt: Two transparent beakers are placed side by side, each containing water. Activated carbon is added to the left beaker, while the right beaker receives no activated carbon. Then, the same amount of food dye solution is poured into both beakers and stirred.

Evaluation guide:
(i) Target concept: Adsorption of soluble dye onto porous solid phase (activated carbon) reduces aqueous-phase concentration and thus optical absorbance.
Minimum mechanism: Dye must remain molecularly dispersed in water (not precipitated); activated carbon must remain insoluble and physically intact; adsorption must occur rapidly upon contact and persist through stirring; no chemical reaction or degradation required.
(ii)Storyline: Frame 0–2: Static wide shot showing two identical transparent beakers with clear water, side-by-side, fixed viewpoint. Frame 3–4: Activated carbon poured into left beaker only, visible as dark granules settling. Frame 5–6: Colored dye solution dispensed identically into both beakers, liquid stream visible, color entering water. Frame 7–9: Stirring rods enter both beakers and rotate synchronously; liquid swirls, particles disperse transiently, then settle. Frame 10: Final still, left beaker shows pale tint + visible black granules; right beaker shows uniform intense color + no particles. All events occur within single continuous take, no cuts, no occlusion, no camera movement.

Manual:
Experimental Procedure
1. Place two identical transparent beakers side-by-side, each filled with clear water.
2. Add activated carbon only to the left beaker.
3. Pour identical amounts of colored food dye solution into both beakers.
4. Stir both beakers simultaneously with identical motion.
Observation of Experimental Phenomena
After stirring, the right beaker water appears uniformly and deeply colored; the left beaker water appears significantly lighter in color and more transparent.
Summary of Experimental Principles
Activated carbon adsorbs food dye molecules from water, reducing color intensity; untreated water retains full dye concentration and color.

Prompt Grounding rubric:
level_1: The scene never shows two clear beakers side by side with water in them; or activated carbon is never added to the left beaker; or the dye solution is never poured into one or both beakers; or no stirring ever takes place.
level_2: Two clear beakers with water do appear side by side, but activated carbon is missing from the left beaker, or dye is missing from one of the beakers, or neither beaker is ever stirred, or the two beakers are never shown together in the same continuous shot.
level_3: Two clear beakers sit side by side, each holding water; activated carbon is added to the left beaker only; a matching amount of dye solution is then poured into both beakers; a stirring rod or utensil visibly stirs both beakers; the events happen in the prompt's order: carbon into the left beaker first, then dye into both, then stirring.
level_4: Everything in level 3 holds, plus: no extra props such as labels, additional beakers, or unrelated tools ever enter the frame; the dye is poured into both beakers at essentially the same moment rather than one much later than the other; the stirring in the two beakers looks like matching motion happening at the same time; the activated carbon stays inside the left beaker the whole time rather than spilling into the right one.
level_5: Everything in level 4 holds, plus: the activated carbon is clearly granular and black or dark gray; the dye is visibly colored (e.g., red, blue, or green) as it enters each beaker; both beakers stay in the exact same spot, size, and orientation from the first frame to the last; no cut, camera move, or obstruction blocks the view of either beaker at any point in the sequence.

Scientific and Causal Correctness rubric:
level_1: After stirring, neither beaker shows any color at all, or both beakers end up looking equally saturated, or the left beaker somehow ends up more intensely colored than the right, or color shows up in a beaker before any dye has been poured into it, or the activated carbon dissolves away or disappears.
level_2: Both beakers do pick up color from the dye, but by the end there's no visible difference in color strength between the left and right beaker; or a color difference shows up before stirring even starts; or the activated carbon sits in the left beaker with no visible effect on how colored that beaker looks.
level_3: After stirring, the right beaker (no activated carbon) looks uniformly and richly colored; the left beaker (with activated carbon) looks noticeably paler or more see-through than the right one; the activated carbon is still visible as solid dark particles inside the left beaker; the left beaker's paler color reads as less dye having taken hold, not just an initial dilution effect.
level_4: Everything in level 3 holds, plus: the color gap between the two beakers is still just as visible once stirring has fully stopped and the liquid has settled; the activated carbon particles stay intact as visible grains rather than disintegrating or vanishing; the color difference reads as a natural result of the carbon's presence rather than an added visual effect applied only to the left beaker.
level_5: Everything in level 4 holds, plus: the paler look of the left beaker is clearly tied to the activated carbon and nothing else: no other powder or solid appears in either beaker; the left beaker's liquid still reads as a translucent liquid (not cloudy or milky), just lighter in color; the right beaker's liquid reads as a clean, uniform color with no floating particles or cloudiness.

Spatiotemporal Consistency rubric:
level_1: Severe continuity breaks: a beaker's position on the table jumps between one moment and the next; activated carbon or dye appears inside a beaker out of nowhere with no pouring motion shown; the room's lighting swings dramatically from one moment to the next with no cause; a beaker's shape warps or bends; the water's level jumps to a different height with no visible cause.
level_2: Smaller but still noticeable problems: the two beakers shift position relative to each other between steps; the activated carbon already looks fully spread through the water before any stirring has started; dye shows up in one beaker well before the other, with no matching pour ever shown for the second beaker.
level_3: Both beakers stay in the same spot and orientation for the whole clip; activated carbon goes in before the dye; the dye is poured into both beakers using a visibly similar motion; stirring only starts once dye is in both beakers; nothing in the shot blinks out of existence or suddenly reappears; the direction and strength of the light on the beakers looks the same from the first frame to the last.
level_4: Everything in level 3 holds, plus: the stirring motion looks smooth and physically natural, with no sudden jerks, instant spinning, or a stirring rod that seems to float on its own; the liquid surface dips and swirls continuously while being stirred, then settles smoothly once stirring stops; the clip runs without any stutter or repeated moment that would break up the sequence of events.
level_5: Everything in level 4 holds, plus: the two beakers keep the same side-by-side spacing, height, and alignment throughout, without drifting apart or closer together; the events unfold in one strict order (beakers with water, then carbon into the left one, then dye into both, then stirring in both, then a final settled shot), with no jump cuts or scene breaks anywhere in between.