Domain: Engineering — Geotechnical Engineering
Target concept: After being submerged at the bottom, water rises through a transparent fine sand column.

Video generation prompt: A transparent vertical tube filled with dry fine sand is placed upright, with its bottom immersed in a shallow pan of water, and observed from the side over time.

Evaluation guide:
(i) Target concept: Capillary rise in unsaturated fine sand under gravitational equilibrium.
Minimum mechanism: Sand must be fine-grained (pore size <0.1 mm), hydrophilic, and initially dry; tube must be rigid, vertical, and hydrophilic inner surface; water must be pure and at rest; no external pressure or flow applied.
(ii)Storyline: [Frame 0] Tube upright, dry fine sand column fully visible, bottom edge contacting calm water surface. [Frame 1–N] Water begins ascending at bottom; a sharp, horizontal wetting front emerges and moves continuously upward through sand. [Throughout] Front remains planar and aligned across tube width; dry sand above stays unchanged in texture and brightness; no splashing, dripping, or lateral spread. Perspective is fixed side view: no top-down or oblique angles; entire sand column and water pan must remain fully in frame with unobstructed visibility of the advancing front.

Manual:
Experimental Procedure
1. Place a transparent vertical tube upright.
2. Fill it completely with dry fine sand.
3. Immerse its open bottom end into a shallow pan of still water.
4. Observe from the side for 10 seconds.
Observation of Experimental Phenomena
Water rises continuously and vertically from the bottom of the sand column, forming a sharp, horizontal wetting front that advances upward through the sand; the region below the front appears visibly darker and more saturated than the dry region above.
Summary of Experimental Principles
After being submerged at the bottom, water rises through a transparent fine sand column due to capillary action — a result of adhesive forces between water and sand particles and cohesive forces within water, enabling spontaneous ascent against gravity in narrow pores.

Prompt Grounding rubric:
level_1: None of the required elements appears: no upright transparent tube, no dry sand inside it, no pan of water beneath it, and the camera is not a side-on view.
level_2: One or two required elements are visible, but the setup is not assembled as described: e.g., the tube is present but empty or lying on its side; sand appears in an open container rather than inside a vertical tube; or a water pan is visible but the tube never touches it.
level_3: The upright transparent tube, a pan of water, and a side-on camera view are all present, and the tube holds a granular fill, but the setup falls short in exactly one way: the fill is not dry fine sand (e.g., pebbles, coarse gravel, or a liquid instead), the tube leans more than about 15° off vertical, or the tube's open bottom hovers above the water instead of touching it.
level_4: The transparent tube stands vertical and is filled with dry fine sand from bottom to near the top; a pan of water sits beneath it with the tube's bottom edge continuously touching the water surface; the side-on camera shows the tube's full height and the water pan; nothing blocks the view of the sand column.
level_5: All score 4 conditions hold, AND the tube sits centered in the frame; the sand grains look uniform and undisturbed before water contact begins; the water surface in the pan is calm and level; no glare, reflection, or lens smearing hides the sand column or the water line; the tube's glass shows no visible scratches or embedded bubbles.

Scientific and Causal Correctness rubric:
level_1: No upward movement of water is visible anywhere in the sand; there is no wetting front, no darkening of the sand, and no sign of capillary rise at all.
level_2: Some upward movement occurs, but not in a way consistent with capillary rise: water surges down from the top, spreads sideways before rising, climbs only along the tube wall's edges, or appears as separate blobs rather than a continuous front; the sand stays uniformly dry-looking throughout.
level_3: Water advances upward from the bottom of the tube into the sand, and a wetting front is visible as a boundary between lighter dry sand and darker wet sand; but the front is uneven (it jumps, stalls, or retreats), or wet patches appear only in isolated spots rather than as a continuous front, or the dry sand above looks barely different in tone from the wet sand below.
level_4: Water rises continuously and vertically from the tube's bottom through the sand; the wetting front is a sharp, roughly horizontal, unbroken line separating clearly darker wet sand below from clearly lighter dry sand above; there is no sideways leakage, no retreat of the front, and no branching; the light/dark contrast stays steady across the whole visible height.
level_5: All score 4 conditions hold, AND the wetting front stays evenly aligned across the full width of the tube as it rises; no sand grains visibly detach or slump during the rise; no air pockets or channels form ahead of the front; the sand's texture looks the same before and after wetting aside from color; the light/dark contrast stays sharp and does not fade or blur as the front advances.

Spatiotemporal Consistency rubric:
level_1: Between one frame and the next, the tube jumps to a different spot or angle with no motion to explain it; the sand column or the water pan blinks out of view and reappears; the room lighting suddenly swings from bright to dim (or the reverse) with no connection to the water rising; the tube appears cracked, bent, or otherwise structurally different than a moment before.
level_2: The tube rocks or twists noticeably with no visible cause; a large mass of sand suddenly slumps downward even though the water hasn't reached it yet; the water surface in the pan churns or ripples heavily and unevenly; the clip stutters or skips frames; the lighting flickers noticeably; part of the setup is hidden in one frame and then unexpectedly visible in the next with no camera movement to explain it.
level_3: The tube shows only slight, camera-shake-level vibration or drift; the water surface shows a faint shimmer that never hides the rising wetting front; a few sand grains settle near the very bottom of the tube independent of the water's rise; the side-on camera view stays the same throughout; the tube, sand, and water pan never disappear or jump between frames.
level_4: The tube stays in the same position and orientation for the whole clip; the sand column keeps its shape except right at the advancing wet front; the water surface in the pan stays calm; scene brightness stays even from start to end; the camera holds still with no zooming or panning; the tube's position relative to the water pan does not shift from frame to frame.
level_5: All score 4 conditions hold, AND the tube shows no detectable drift in position from the first frame to the last; the wetting front rises at a steady, continuous pace rather than in fits and starts; the water surface in the pan moves only with small, physically reasonable ripples; the clip shows no stuttering, freezing, or repeated frames as the front advances.