Domain: Natural Science — Biophysics
Target concept: Gelatin solidifies during cooling (protein chains form a gel network)

Video generation prompt: Pour the warm dissolved gelatin into two shallow, transparent containers; place one in the refrigerator and the other on the lab bench, and record the process by occasionally gently tilting the containers.

Evaluation guide:
(i) Target concept: Temperature-dependent sol-gel transition of gelatin via reversible protein network formation.
Minimum mechanism: Gelatin must be initially dissolved (homogeneous liquid phase) and cooled below gelation temperature (~15–20°C) to form a viscoelastic solid; ambient bench temperature (>22°C) must remain above gelation threshold to prevent solidification.
(ii)Storyline: [Phase 1] Warm gelatin poured into two containers → [Phase 2] Containers placed side-by-side: one enters refrigerator interior (door open/closed, cold context implied), one rests on bench → [Phase 3] After sufficient cooling time (implied, not timed), tilting begins → [Phase 4] Refrigerated container shows no deformation/flow (solid state); bench container shows immediate, coherent flow (liquid state) → [Phase 5] Both containers return to level orientation; states persist unchanged → Perspective: Fixed frontal/slightly elevated viewpoint capturing both containers, refrigerator, and bench simultaneously; full container bodies and tilt motion must remain fully visible without cropping or occlusion.

Manual:
Experimental Procedure
1. Pour warm dissolved gelatin into two identical shallow transparent containers.
2. Place one container inside a refrigerator; place the other on a lab bench—both visible side-by-side.
3. At multiple time points, gently tilt each container by hand while recording.
Observation of Experimental Phenomena
- Refrigerated container: no flow during tilt; maintains shape; surface does not deform.
- Bench container: flows during tilt; surface deforms; forms meniscus; resumes flat surface when level.
Summary of Experimental Principles
Gelatin solution solidifies into a gel upon cooling because thermally induced protein chain mobility decreases, allowing hydrogen bonds and hydrophobic interactions to form a stable 3D network that traps water.

Prompt Grounding rubric:
level_1: No gelatin-filled containers appear; no refrigerator and no lab bench are shown; there is no pouring action and no tilting motion. Nothing from the setup is present.
level_2: Only one shallow transparent container appears rather than two, or only one location (refrigerator or bench) is shown rather than both; the pouring action and the tilting motion are both missing.
level_3: Two shallow transparent containers sit side by side in the same shot; one is positioned at a refrigerator (its door, handle, or interior visible) and the other at a lab bench (a flat surface with a visible edge or leg); warm liquid is shown being poured into the container(s), but a tilting motion is shown for at most one of the two containers, or not at all.
level_4: All conditions of score 3 hold, and a gentle tilt is shown for both containers at least once each within the same continuous shot; each container sits still between tilts; the refrigerator and the bench are both visible together without a scene cut or camera repositioning to reveal them.
level_5: All conditions of score 4 hold, and the two tilting actions match each other closely: both begin and end at roughly the same point in the video, tilt in a comparable direction and for a comparable duration, and the two containers keep the same size, transparency, and fill level as each other before either is tilted; there is no scene cut, camera jump, or object swap between the pouring and the tilting shots.

Scientific and Causal Correctness rubric:
level_1: Both containers show the exact same behavior under tilt (either both flow or both hold their shape), or the assignment is reversed from what cooling physics predicts (the refrigerated gelatin flows like a liquid while the bench-top gelatin holds a fixed shape).
level_2: Only one container's behavior changes from the initial poured-liquid state, but the change itself is not physically gradual: for instance the refrigerated gelatin suddenly holds a rigid shape from the very first tilt with no visible thickening beforehand; or a container's flow behavior contradicts its own visible tilt (the gelled container is shown sagging and flowing when tilted as if it were still liquid, or the still-warm bench container is shown holding a fixed molded shape as if it had set).
level_3: Two distinct behaviors appear under tilt: the refrigerated container holds its poured shape with no flow and no surface deformation, while the bench container visibly flows, forms a sloped meniscus, and deforms at the surface when tilted; this contrast is shown without ever reversing.
level_4: All conditions of score 3 hold at every tilt shown, not just once: the refrigerated container never flows at any tilt, and the bench container never fully sets (no frame shows it holding a fixed shape, a skin, or a stiff edge); the two behaviors stay assigned to the same container throughout.
level_5: All conditions of score 4 hold, and each state looks physically coherent in detail: the set gelatin holds one continuous solid mass with no visible crack, split, or separate pooled liquid at its edges; the still-liquid gelatin shows a smoothly curved surface with no unnatural shearing or breaking into separate blobs when tilted; both behaviors stay exactly the same every time tilting is repeated.

Spatiotemporal Consistency rubric:
level_1: A container vanishes from one frame and reappears in another, the room lighting suddenly changes (e.g., daylight to darkness) with no cause shown, a container's shape distorts or stretches inconsistently between frames, or a tilt motion suddenly jumps to a different angle or reverses direction without transition.
level_2: One container disappears and reappears at least once; the tilt motion shows two or more visible breaks (e.g., a pause followed by a sudden jump, or a reversal mid-tilt); the shadow cast by a container shifts position or brightness in a way the fixed room lighting does not explain; or a container's edge flickers or blurs severely between frames.
level_3: Both containers stay visible and in the same place throughout except for the tilt motion itself (no unexplained sliding, spinning, or resizing); each tilt is a single smooth, one-directional motion; the shadows the containers cast keep the same direction and darkness from frame to frame; neither container's rim or wall ever appears to break open or gap.
level_4: All conditions of score 3 hold, and the two containers keep the same fixed distance from each other throughout (never drifting closer or farther apart); each tilt rotates around the same point on the container's base every time it happens; the refrigerator and the bench stay fully visible and unmoving in the background, never partly hidden by anything passing in front.
level_5: All conditions of score 4 hold, and the pacing feels natural throughout: each tilt moves at a steady speed without sudden speed-ups or slow-downs, the motion looks like a continuous hand tilting the container rather than a series of snapped poses, and there is no frame that repeats, skips, or shows the tilt happening in reverse order.