Domain: Natural Science — Chemistry
Target concept: Inserting a burning wooden splint into a bottle of carbon dioxide causes the splint to extinguish immediately, does not reignite, and leaves no glowing embers.

Video generation prompt: Prepare a bottle filled with carbon dioxide gas. Light a splint and allow it to burn steadily, then vertically insert the burning splint into the bottle opening. Keep the bottle stationary and hold the splint with your hand. Focus only on the correct use of the apparatus and the proper sequence of operations.

Evaluation guide:
(i) Target concept: Demonstration that carbon dioxide is a non-combustible, oxygen-displacing gas whose presence causes immediate and irreversible flame extinction in a confined volume.
Minimum mechanism: Bottle must contain sufficiently pure CO₂ (visually indistinguishable from air but functionally inert); splint must be burning with sufficient fuel mass to sustain flame outside bottle; insertion must breach the CO₂-rich headspace to trigger rapid deoxygenation at the reaction zone.
(ii)Storyline: [Frame 0–2] Stable shot: upright bottle centered, hand holding lit splint just outside bottle opening, flame fully alight. [Frame 3–5] Splint tip crosses bottle opening plane: flame remains intact up to this boundary. [Frame 6–7] Flame extinguishes *only after* tip enters bottle volume: no glow, no smoke-dominated persistence. [Frame 8–10] Splint withdrawn showing blackened, non-glowing tip; no reignition; bottle remains motionless. Perspective: Fixed frontal view, eye-level, full visibility of bottle opening, splint tip, and hand; no occlusion at critical transition frames.

Manual:
Experimental Procedure
1. Prepare upright, transparent bottle filled with carbon dioxide.
2. Light wooden splint and allow flame to stabilize.
3. Hold splint vertically in hand; insert burning tip steadily into bottle opening.
4. Keep bottle stationary; observe splint tip inside bottle.
Observation of Experimental Phenomena
Flame extinguishes immediately upon entering bottle; no reignition occurs; no glowing embers remain on splint tip after removal.
Summary of Experimental Principles
Carbon dioxide does not support combustion; its higher density displaces air and surrounds the splint, cutting off oxygen supply — causing immediate flame extinction without ember persistence.

Prompt Grounding rubric:
level_1: No bottle visible; no burning splint visible; no insertion action shown; no stationary bottle or hand-held splint present; objects or actions completely mismatch posted_prompt.
level_2: Bottle and splint are present but incorrectly configured: e.g., splint is unlit, bottle is empty or mislabeled, splint is inserted horizontally or from below, bottle is tilted or moving, hand is not holding splint, or splint is not vertically inserted toward bottle opening.
level_3: Bottle (clear/glass-like container) and burning splint are both present; splint is lit and visibly flaming; splint is vertically oriented and inserted toward the bottle opening; bottle remains stationary; hand is holding splint. All core objects and actions from posted_prompt are present in correct type and spatial relationship, but sequence may be disordered (e.g., splint inserted before flame stabilizes) or one non-core element missing (e.g., no visible bottle label, unclear opening orientation).
level_4: All core objects (bottle, burning splint, hand) are present with correct type and appearance; vertical insertion of splint into bottle opening is clearly executed; bottle remains stationary throughout; hand holds splint continuously during insertion; no extraneous tools or actions; only one non-core flaw exists (e.g., splint briefly wobbles without affecting vertical alignment, or bottle has faint condensation not specified in prompt).
level_5: Bottle (transparent, upright, gas-filled appearance implied by clarity and lack of liquid), burning splint (flaming tip, no smoke dominance), and hand are all present with correct visual identity; splint is lit *before* insertion and maintains steady flame until insertion begins; insertion is strictly vertical, directed precisely at bottle opening; bottle is motionless and centered in frame; hand remains stable and fully visible holding splint throughout; no extraneous objects, motions, or occlusions at any point.

Scientific and Causal Correctness rubric:
level_1: Splint remains fully alight inside bottle; flame grows, flickers strongly, or reignites; glowing embers persist or appear after removal; no extinguishment observed; phenomenon contradicts carbon dioxide property entirely.
level_2: Splint extinguishes but shows ambiguous timing (e.g., flame fades slowly over >1s while still outside bottle); glowing embers appear *after* removal; splint reignites spontaneously; or flame extinguishes *before* reaching bottle opening. The causal link between CO₂ exposure and extinction is visually broken.
level_3: Flame extinguishes *during* or *immediately upon* crossing the bottle opening plane; no reignition occurs; no glowing embers remain on splint tip after removal; all three phenomena (extinguish, no reignite, no embers) are visually confirmed, but temporal precision is loose (e.g., extinguishment occurs slightly before full insertion depth, or ember absence is inferred rather than clearly shown post-removal).
level_4: Flame extinguishes *only after* splint tip crosses the bottle opening plane and enters the bottle volume; extinction is rapid and complete (no residual flame or sustained glow); no reignition occurs at any time; no glowing embers visible on splint tip *after full withdrawal* from bottle; all three phenomena occur as described, with no contradictory visual evidence; only one minor deviation is present (e.g., a single faint ember spark at the tip lasting under roughly a quarter second before going out, or slight smoke residue obscuring the tip view momentarily).
level_5: Flame is fully alight *up to* the instant splint tip crosses the bottle opening plane; extinction occurs *within the same continuous motion* and *exclusively inside* the bottle volume; zero flame or glow persists beyond that moment; splint is withdrawn showing a blackened, non-glowing tip with no ember emission at any frame; no reignition, no delayed glow, no smoke-based ambiguity; the causal chain (CO₂ environment → immediate flame extinction → no ember persistence) is unambiguously and exclusively visible.

Spatiotemporal Consistency rubric:
level_1: Bottle teleports or changes position/size mid-video; splint discontinuously appears/disappears or jumps location; overall scene brightness switches abruptly (e.g., flashes from bright to dark) with no hand, object, or light source visibly causing it; the flame vanishes or reappears mid-frame with no burning-down or relighting motion shown; splint or bottle visibly bends through itself or fractures and reforms.
level_2: Bottle wobbles or rotates without any hand or surface contact causing it; splint bends unnaturally as it is lowered toward the opening; hand motion jerks or stutters; flame separates from the splint tip and drifts on its own; the glow the flame casts on the bottle's curved glass surface jumps to a different spot or disappears without the flame or hand having moved; background objects shift position relative to the bottle with no camera motion to explain it.
level_3: Bottle stays fixed on the table; splint descends smoothly along a vertical path toward the opening; hand tracks the splint's motion without lagging behind or overshooting; flame stays attached to the splint tip with ordinary flicker; the flame's glow reflected on the bottle's glass tracks smoothly downward as the splint lowers, without jumping or disappearing; no teleporting, warping, or bending is visible, though the splint's downward path may waver very slightly, or the tip may be briefly hard to make out during the fastest part of the motion.
level_4: Bottle is visibly motionless with no shake or vibration; splint moves straight down toward the opening in one continuous motion with no pause, reversal, or sideways drift; hand moves together with the splint with no slipping; flame stays anchored to the tip with only natural, small flicker (no floating or unnatural pulsing); the reflected glow of the flame on the bottle's glass surface moves smoothly and continuously downward in step with the splint, never jumping ahead or disappearing early; only one small artifact is visible elsewhere (e.g., a single brief flash of glare on the glass unrelated to the flame's motion, or the hand's edge briefly grazing the view without hiding the flame).
level_5: Bottle's position, upright orientation, and size look identical from the first frame to the last; splint tip travels in a visibly straight vertical line down into the bottle opening with no sideways wobble at any point; hand's grip and position stay steady and fully in view throughout; flame's shape changes only the way an ordinary flame naturally would (no rigid, frozen, or strobing look); the flame's reflected glow on the glass moves in lockstep with the splint's descent from first appearance until the tip passes the opening, with no jump, freeze, or disappearance at any point; there is no blurring or mismatched framing that would make any part of the motion look discontinuous.