Domain: Natural Science — Physics
Target concept: Sound Transmits Energy

Video generation prompt: Lay a double-headed drum on its side on a table so its cylindrical shell rests on the tabletop and the two flat drumheads form vertical planes perpendicular to the table surface, one facing left and one facing right. Place a burning candle near the left drumhead so the candle's flame sits directly in front of it. Strike the right drumhead forcefully to send sound through the drum to the candle's location.

Evaluation guide:
(i) Target concept: Sound is a mechanical wave that carries kinetic energy through a medium (air) via particle vibration; when the wave reaches a taut membrane, the membrane's own oscillation displaces the adjacent air, and that displaced air can push a low-mass object (here, a candle flame) placed in its path.
Minimum mechanism: air must be present as the transmission medium; both drumheads must be taut membranes coupled to the surrounding air; the candle flame must be light and close enough to the left drumhead to respond to the resulting air pulse; the strike on the right drumhead must be forceful enough to set the left drumhead oscillating.
(ii) Storyline: [Frame 0-2] Static setup: drum resting on its side, candle fixed near the left drumhead, flame upright and steady, right drumhead untouched. [Frame 3-4] Strike initiation: a hand or mallet contacts the right drumhead; nothing else in frame is moving yet. [Frame 5-6] Causal propagation: the left drumhead begins visible surface vibration within a frame or two of the strike. [Frame 7-8] Effect manifestation: the flame tip visibly deflects away from the left drumhead (pushed further outward by the air pulse the vibrating membrane sends toward it), not sideways or upward. [Frame 9-10] Decay phase: the drumhead's vibration subsides and the flame returns to its upright resting position, confirming that the energy transfer was transient. Perspective: fixed frontal view, eye-level or slightly elevated, keeping the drum's full length, both drumheads, and the candle from base to flame tip unobstructed.

Manual:
Experimental Procedure
1. Lay the double-headed drum on its side on the table so both drumheads form vertical planes perpendicular to the tabletop, one facing left and one facing right.
2. Position the burning candle near the left drumhead, with its flame oriented toward that drumhead.
3. Strike the right drumhead forcefully.
Observation of Experimental Phenomena
The left drumhead vibrates visibly, and the candle's flame deflects away from the left drumhead, pushed further outward by the air the vibrating membrane displaces.
Summary of Experimental Principles
Sound is a mechanical wave that carries energy through a medium such as air. Striking the right drumhead sends pressure waves through the drum's interior air and shell to the left drumhead, setting it into vibration. As the left drumhead oscillates outward, it pushes a pulse of air toward the candle; that moving air pulse continues outward past the drumhead and deflects the flame away from it, demonstrating that sound transports mechanical energy through a medium without any net transport of matter.

Prompt Grounding rubric:
level_1: No double-headed drum is present; or no candle is present; or the drum is not resting on its side with both drumheads forming vertical planes (e.g., it stands upright with drumheads on top and bottom instead); or the candle is not placed near the left drumhead; or the flame does not face the left drumhead; or the right drumhead is never struck; or any core object is missing or misidentified (e.g., a single-headed drum, a bottle standing in for the drum, or an unlit wick instead of a burning flame).
level_2: The drum and candle are both present and roughly recognizable, but at least three of the following are wrong: the drum's body is not lying on its side (its drumheads are not vertical), the candle is not on the left, the flame does not face the left drumhead, the right drumhead is never struck, or the two drumheads do not sit on opposite ends of the same drum body. No clear spatial link between the strike location and the candle's location is established.
level_3: The drum lies on its side on the table with both drumheads forming vertical planes perpendicular to the tabletop; the candle sits near the left drumhead with its flame oriented toward that drumhead; the right drumhead is struck, with a hand, mallet contact, or a clear impact motion visible; every object and action from the setup (drum, candle, flame, and strike) is present and recognizably positioned, though one or more relationships may be ambiguous (for instance, smoke partly hides the flame's orientation, the strike's timing relative to the drum's stability is unclear, or the drum is slightly tilted but still clearly resting on its side).
level_4: Building on that baseline scene, the drum's resting orientation is completely unambiguous, with no tilt obscuring which axis is vertical; the candle sits clearly beside the left drumhead rather than behind or above it; the flame is unmistakably oriented toward the left drumhead's face; the right-drumhead strike is visually distinct and occurs while the drum is stationary; and no extraneous objects block the view of either drumhead or the flame.
level_5: Going a step further still, the drum stays completely still both before and after the strike, with no incidental sway; the candle flame burns steadily and is never occluded; the strike reads as a single, cleanly isolated action with no other motion happening at the same time; and the camera holds one fixed framing for the whole clip, with no cut, pan, or zoom that breaks the spatial continuity of the drum, candle, and flame.

Scientific and Causal Correctness rubric:
level_1: No flame reaction to the strike is visible; or the flame goes out for a reason unrelated to the strike (e.g., an off-scene draft or the candle tipping over); or the flame deflects toward the left drumhead instead of away from it; or the left drumhead shows no vibration at all, or shows vibration before the right drumhead is ever struck.
level_2: The flame does move, but the timing or direction breaks the causal chain: for example, it moves before the strike happens, it moves sideways or upward rather than away from the left drumhead, or only the right drumhead shows any vibration while the left drumhead stays motionless; or the flame's motion has no visible connection to the left drumhead's vibration.
level_3: After the right drumhead is struck, the left drumhead visibly vibrates (a ripple or surface oscillation is visible), and, within about a frame or two, the flame tip visibly deflects away from the left drumhead, consistent with an outward air pulse pushing it further from the drum. The causal order of strike, then left-drumhead vibration, then flame deflection is present, even if the deflection is small or briefly obscured by smoke or lighting.
level_4: Building further on that causal sequence, the flame's deflection is unambiguously directed away from the left drumhead rather than sideways or upward; the left drumhead's vibration reads clearly as a surface ripple rather than a mere blur; and the flame's motion begins only after the drumhead's vibration is already visible, with no other apparent cause such as a hand passing near the flame or a visible draft.
level_5: Taking that a step further, the flame's outward deflection lasts long enough to be clearly seen rather than flickering for a single frame; the left drumhead's vibration dies down smoothly and fairly symmetrically rather than jerking irregularly; and the flame settles back into its original upright position once the drumhead's vibration has visibly faded, showing the complete transfer and decay of the sound energy from strike to flame and back to rest.

Spatiotemporal Consistency rubric:
level_1: The drum's position or size changes discontinuously between frames: for instance, it jumps to a different spot on the table or its scale suddenly changes; the candle or its flame drops out of the frame entirely and then reappears with no occluding object in between; the left drumhead's surface tears, duplicates, or shows a visible seam break while vibrating; the camera's framing changes abruptly, as if the shot had been cut, partway through the clip; or the scene's lighting swings abruptly between bright and dark with no cause tied to the strike or the candle.
level_2: The drum or candle shifts noticeably on the table with nothing (no strike, no bump, no contact) to explain it: for example, the candle's base slides sideways between frames; the flame's shape becomes physically incoherent, splitting into separate disconnected flames or twisting into a shape a real flame could not hold; or the vibrating left drumhead's surface flips between visibly different, inconsistent textures instead of reading as one continuous membrane.
level_3: The drum, candle, and table hold one fixed spatial arrangement for the whole clip: nothing slides, jumps, or changes scale; the flame stays attached to the wick at every point in the clip; small rendering imperfections may appear, such as a brief dip in the flame's brightness or the drumhead's fastest-moving rim looking momentarily soft, but nothing breaks the impression of one continuous scene.
level_4: Beyond that baseline continuity, the camera's framing never shifts at all: no pan, tilt, or zoom; the drum's body stays in continuous contact with the table with no floating or visible gap; the flame's attachment to the wick never wavers or flickers out; and the left drumhead's vibration reads as one continuous, unbroken motion rather than jumping between a few static-looking poses.
level_5: At the highest level of fidelity, motion throughout the clip reads as fluid from frame to frame, with no stutter or repeated frame; once the left drumhead's vibration subsides, its surface returns cleanly to a flat resting shape with no leftover warping or texture smear; and the candle's flame, along with any smoke or heat shimmer around it, moves continuously with no abrupt reappearance or sudden change of shape at any point in the clip.