Domain: Natural Science — Earth Science
Target concept: Tank with an immersed vibration source generating surface ripples

Video generation prompt: A clear tank with a small vibration source fixed at the central position just below the water surface; it continuously transmits vibrations into the water when activated.

Evaluation guide:
(i) Target concept: Mechanical surface wave generation via immersed point source in a bounded liquid medium.
Minimum mechanism: A sustained, localized oscillation beneath the water surface must couple energy into the air-water interface, producing outward-propagating transverse disturbances that obey radial symmetry and amplitude decay—requiring immobile source, quiescent initial state, and absence of confounding forces (e.g., wind, currents, container resonance).
(ii)Storyline: [Frame 0–2] Still water surface, centered submerged source visible through tank wall; [Frame 3–4] First ripple crest appears at center; [Frame 5–8] Ripples expand continuously as concentric circles at a steady outward speed, maintaining circular symmetry and a consistent spacing between adjacent rings; [Frame 9–10] Ripple propagation continues smoothly with visible amplitude decay toward edges; all phases viewed from fixed frontal/slightly elevated perspective ensuring full visibility of water surface and central source location.

Manual:
Experimental Procedure
1. Fill a clear rectangular glass tank with still water to 80% height.
2. Fix a small mechanical vibration source (e.g., miniature speaker or piezoelectric actuator) so that it sits horizontally centered in the tank and just below the water surface, without touching the tank bottom.
3. Activate the source to generate continuous vibrations.
Observation of Experimental Phenomena
Concentric circular ripples emerge continuously from the center of the water surface and propagate outward symmetrically; ripples remain confined to the water-air interface with no splashing or subsurface disturbance.
Summary of Experimental Principles
Mechanical wave generation: A localized periodic disturbance in an elastic medium (water) produces transverse surface waves; wavefronts expand radially due to isotropic propagation in a homogeneous, bounded 2D surface layer.

Prompt Grounding rubric:
level_1: No clear tank or water is shown, no vibration source is present, and no ripples appear anywhere on a water surface.
level_2: A transparent rectangular tank is shown but contains no water; or a small source object sits near the center but stays above the waterline instead of below it; or a vibration source is visible while clearly disconnected from the water; ripples appear on the surface with no source visible to explain them.
level_3: A clear rectangular tank filled with water is shown; a small vibration source (e.g., a miniature speaker or piezoelectric actuator) sits near the horizontal center of the frame; the source is visibly below the water line, with water clearly covering it; ripples originate from the central region of the water surface.
level_4: All elements of 3-score are present AND the vibration source stays at the same horizontal center position for the whole sequence; ripples stay confined to the water surface with no splashing, no bubbles rising from the source, and no disturbance of the tank bottom; no hands, tools, or on-screen labels enter the shot.
level_5: All elements of 4-score are present AND the vibration source is entirely submerged with no part breaking the surface; the water is calm and flat before the first ripple appears; ripples visibly originate from a single point at the center rather than a spread-out area; the tank walls stay clear, with no glare or distortion hiding the source or the central water region.

Scientific and Causal Correctness rubric:
level_1: Ripples appear on the water surface with no connection to the source; the disturbance travels upward into the air or downward into the tank instead of along the surface; the ripples form circles that originate from a corner or edge rather than the center; the water itself changes color, clarity, or state (e.g., frothing, boiling, freezing) instead of simply rippling.
level_2: Ripples start near the center but spread unevenly, reaching fully in one direction while barely reaching another; new rings appear discontinuously, skipping outward or vanishing and reappearing elsewhere; the source itself visibly shifts position while producing ripples; the water surface shows sloshing or swirling motion not explained by a single point source.
level_3: Ripples originate continuously from the submerged central source and expand outward as circular wavefronts across the water surface; no ripple activity appears away from the source's location; no second source or crossing wave pattern competes for attention in the frame.
level_4: All elements of 3-score are present AND each expanding ring keeps a circular shape as it travels outward, without flattening or clipping near the tank walls; ripple height visibly decays with distance from the source, so outer rings look lower or fainter than inner ones while all remain visible surface disturbances.
level_5: All elements of 4-score are present AND the wavefronts' outward speed stays constant through the sequence, neither accelerating nor slowing as the rings travel farther from the source; the spacing between neighboring rings stays even across the visible surface at any given moment, matching a single constant wavelength from a steadily oscillating source rather than spacing that widens or narrows with distance.

Spatiotemporal Consistency rubric:
level_1: The tank or the vibration source disappears or jumps to a different spot between frames; the water surface flickers out and reappears; the lighting suddenly flashes or the scene goes dark; the camera view cuts, pans, zooms, or tilts partway through the sequence; the tank wall or water surface shows a visible seam, tear, or warped break.
level_2: The vibration source visibly wobbles or drifts away from its starting spot over the course of the video; a bright reflection on the water surface jumps to a new location without a matching change in the light; the source's shadow moves independently of the source itself; the tank's base or side walls appear to shift in perspective from one frame to the next as though the camera had moved.
level_3: The camera viewpoint stays fixed with no panning, zooming, or tilting; the tank keeps its rigid rectangular shape and transparency throughout; the vibration source stays at the same horizontal position and fully inside the frame; the water surface stays level and unbroken aside from the ripples; the lighting stays steady with no strobing or sudden shift in direction.
level_4: All elements of 3-score are present AND no motion blur smears the ripples or the source enough to obscure their shape; the ripples and source never appear doubled or ghosted between adjacent frames; the water surface stays uniformly smooth apart from the ripples themselves; the ripple motion never appears to freeze or stutter frame-to-frame.
level_5: All elements of 4-score are present AND the ripples expand with smooth, continuous motion across the entire sequence rather than visibly jumping or snapping between positions; the source stays visibly still at the same spot rather than drifting or trembling; the reflected highlight on the water responds naturally and consistently to a single steady overhead light throughout.