Domain: Natural Science — Physics
Target concept: Oil-water separation, demonstrating the hydrophobic behavior of lipids

Video generation prompt: Pour water and colored cooking oil into a transparent glass container, shake gently, then place it on the table and let it stand still.

Evaluation guide:
(i) Target concept: Immiscibility and density-driven stratification of polar vs. nonpolar liquids.
Minimum mechanism: Water must be polar and denser; cooking oil must be nonpolar and less dense; intermolecular forces must prevent hydrogen bonding between oil and water molecules; gravitational acceleration must dominate over Brownian motion to enable macroscopic separation.
(ii)Storyline: [Phase 1: Setup] Container stationary; water poured first → visible meniscus and clarity. [Phase 2: Addition] Colored oil poured second → immediate non-mixing, forming distinct upper lens-shaped pool. [Phase 3: Mixing] Gentle upright shaking → transient turbidity and droplet dispersion. [Phase 4: Separation] Stillness begins → oil droplets coalesce and rise continuously; water sinks; interface sharpens progressively. [Phase 5: Equilibrium] Two flat, homogeneous, horizontally aligned layers with unbroken interface; full visual stability. Perspective: Fixed frontal view, centered on container mid-height, unobstructed line of sight to full liquid column; no oblique angles that compress layer height or distort interface geometry.

Manual:
Experimental Procedure
1. Pour clear water into a transparent glass container.
2. Pour colored cooking oil (e.g., yellow or red) into the same container.
3. Gently shake the container upright for ~1 second.
4. Place container upright on table and let stand still.
Observation of Experimental Phenomena
After standing, two distinct horizontal layers form: colored cooking oil floats uniformly above water; a sharp, flat interface separates them; no mixing or droplets remain.
Summary of Experimental Principles
Oil and water are immiscible due to polarity mismatch; oil is less dense than water, so it rises and forms a separate upper layer—demonstrating hydrophobic behavior and density-driven phase separation.

Prompt Grounding rubric:
level_1: No transparent glass container is shown; water is absent; colored cooking oil is absent; neither the pouring, the shaking, nor the stillness phase is depicted.
level_2: A transparent glass container is visible, but at least one required element is missing (water, colored oil, the pouring action, the shaking action, or the stillness phase), or a core object is wrongly substituted (e.g., the oil shown with no color, or the container shown opaque).
level_3: The transparent glass container, clear water, and colored cooking oil (e.g., yellow or red) are all present and visually identifiable; water is poured in first, then the colored oil is poured in, then the container is shaken gently; all three actions occur in this order; a stillness phase follows with the container resting on a surface.
level_4: Both liquids go into the same single container rather than separate ones; the pour of water, then oil, precedes the shaking; the container stays upright and closed to spills throughout the shake; once shaking stops, the container sits undisturbed for a clearly sustained stillness phase with no repositioning or tilting.
level_5: Before shaking, the clear water and the colored oil are visibly distinguishable by color and show no premature mixing; no hand, tool, or other object remains in frame once the pouring and shaking actions are complete; the container, water, and oil are the only substantive elements on screen for the full clip, matching the prompt's setup exactly.

Scientific and Causal Correctness rubric:
level_1: The two liquids appear to fully mix into one uniform-colored fluid with no separation at any point, or the oil appears to dissolve or sink permanently below the water, or water and oil behave identically (e.g., both appear to settle by the same density), contradicting the basic immiscibility and density difference between oil and water.
level_2: Some separation eventually appears, but it violates the underlying physics: for instance the colored oil ends up below the water, or a layer forms with no visible interface between the two liquids, or the two liquids never appear turbid or mixed at any point during the shake, making it impossible to tell whether real mixing and re-separation actually took place.
level_3: After shaking and settling, two flat horizontal layers are visible with the colored oil on top and the clear water beneath it; a continuous, flat interface separates them with no lingering droplets or cloudiness in either layer; the color of the oil (e.g., clear/colorless water beneath yellow or red oil) makes the identity of each layer easy to distinguish.
level_4: During shaking, the liquids visibly turn cloudy and turbulent, showing genuine temporary mixing rather than the two liquids staying in separate layers throughout; as soon as shaking stops, oil droplets visibly begin merging together and rising while the water settles beneath them, with the separation progressing steadily from a mixed state to the final two-layer arrangement.
level_5: By the end of the clip, neither layer retains any visible droplets of the other liquid: the oil layer looks uniformly colored and clear, and the water layer looks uniformly clear beneath it; the flat interface between them runs level all the way across the container with no dimpling, distortion, or leftover haze along the boundary.

Spatiotemporal Consistency rubric:
level_1: The container's position or size changes abruptly between frames with no in-between motion; liquids appear to jump from one configuration to another without a visible transition; the light on the scene or the direction of shadows shifts suddenly partway through with no cause; the container appears to rotate or flip with no hand or force shown causing it.
level_2: The container shifts slightly in position or angle without a smooth motion connecting the frames; a hand or tool that pours or shakes the container disappears from the shot without ever visibly leaving; the lighting on the scene changes noticeably between the shaking and settling phases; shadows cast by the container point in a direction inconsistent with a single, fixed light source.
level_3: The container stays in the same position and orientation across pouring, shaking, and settling; each action unfolds as continuous, physically plausible motion rather than jumping between static states; the direction and brightness of the light on the container and liquids stay the same from the first frame to the last; any hand that enters to pour or shake is shown entering and leaving the frame rather than appearing or vanishing abruptly.
level_4: The poured liquids show a natural stream and splash instead of appearing already inside the container without a visible pour; the shaking motion looks like a small, repeated back-and-forth or up-down movement rather than a sudden jump or spin; once shaking ends, the oil's rise and the water's settling proceed as one uninterrupted motion with no freezing or skipping partway through.
level_5: The camera holds the exact same framing and distance on the container for the entire clip, with no pan, zoom, or cut; the container's outline and the liquids inside move only in ways consistent with gravity and the shaking motion: no unexplained warping, flickering, or double-imaging of the container or its contents at any point.