Domain: Natural Science — Biophysics
Target concept: The GFP-labeled sample emits light under blue excitation.

Video generation prompt: In the laboratory, a petri dish containing cells expressing GFP is placed on the workbench, and a blue excitation light is directed at the dish, being turned on and off repeatedly.

Evaluation guide:
(i) Target concept: Fluorescence-based optical reporting in live cells using GFP.
Minimum mechanism: GFP must be expressed intracellularly; blue light must be absorbed by GFP chromophore; energy relaxation must emit green photons; no photobleaching or delayed emission permitted within video duration.
(ii)Storyline: [Frame 0–2] Static shot of a dimly lit petri dish with cells on the workbench, blue light OFF → no green emission visible. [Frame 3–4] Blue light turns ON → green emission appears instantaneously and only over cellular regions. [Frame 5–6] Blue light turns OFF → green emission vanishes completely and immediately. [Frame 7–8] Blue light turns ON again → identical green emission reappears. [Frame 9–10] Blue light turns OFF again → emission extinguishes identically. Perspective: Fixed frontal/oblique view; dish fully visible; no occlusion; lighting direction consistent; the ambient room lighting is kept dim throughout (rather than brightly lit) so the green emission stays clearly visible to the eye without requiring a barrier filter, consistent with how GFP fluorescence is normally observed.

Manual:
Experimental Procedure
1. Dim the ambient room lighting in the laboratory (enough to see the workbench, but avoiding bright overhead illumination).
2. Place a petri dish containing live cells expressing GFP on the laboratory workbench.
3. Direct a blue excitation light source onto the dish.
4. Turn the blue light ON and OFF repeatedly (minimum two full cycles).
Observation of Experimental Phenomena
Under the dimmed room lighting, green fluorescence appears exclusively inside the dish, only while the blue light is ON, and disappears completely each time the blue light is turned OFF.
Summary of Experimental Principles
GFP (Green Fluorescent Protein) absorbs blue light (~488 nm) and emits green light (~509 nm) via fluorescence; because this emission is much fainter than typical bright room lighting, ambient lighting is dimmed so the green glow remains visible to the unaided eye; emission requires excitation and ceases immediately upon its removal.

Prompt Grounding rubric:
level_1: No petri dish appears in the video; no cells or cell-like material are shown inside a dish; no blue light source appears; the light is never switched on and off; the scene is not set on a laboratory workbench.
level_2: A dish and a blue light source both appear somewhere in the frame, but not as one connected setup; e.g., the blue light is never aimed at the dish, or the dish holds an obviously non-cellular substance such as clear or colored liquid with no visible cell layer; the light turns on but is never turned back off (or vice versa), so no full cycle is completed.
level_3: A petri dish holding a visible layer or cluster of cells sits on a workbench; a blue light source is aimed at the dish; at least one complete ON-then-OFF cycle of the blue light is shown; the dish and its contents remain in place on the bench throughout.
level_4: All elements of score 3 are met, and at least two complete ON/OFF cycles of the blue light are shown; the dish is transparent with the cell material visible as a distinct layer or patch rather than suspended within a large volume of liquid; the blue light is aimed from above or at an oblique angle onto the dish, not from underneath or from behind the bench.
level_5: All elements of score 4 are met, and the petri dish stays centered and fully unobstructed in frame for the entire sequence; the blue light source itself (e.g., a lamp head or handheld emitter) is visually distinct from the dish, with its housing clearly recognizable; the cell layer covers a clear majority of the dish's visible bottom surface; no unrelated object (glove, pipette, label, or hand) enters or blocks the dish at any point during the ON/OFF cycling.

Scientific and Causal Correctness rubric:
level_1: No green glow appears at any point, even while the blue light is on; or a glow is present but shows no relationship to the blue light's state at all; for example, the dish glows green continuously regardless of ON/OFF, or it glows a clearly different color such as red or white.
level_2: A glow appears only while the blue light is on, but something about it is wrong: it is the wrong color (e.g., cyan, yellow, or whitish-green), or it fills the entire dish or liquid rather than tracking the cell layer specifically, or it visibly lingers for a noticeable stretch after the blue light switches off instead of disappearing with it.
level_3: A green glow appears only during the ON portions of each cycle and stays confined to the area of the dish where the cell layer sits; no green glow is visible during any OFF portion; across all the ON/OFF cycles shown, the glow's on/off pattern matches the blue light's on/off pattern every time.
level_4: All elements of score 3 are met, and in every ON frame the green glow is clearly brighter than the surrounding dish and background, so it reads as a genuine emitted glow rather than a faint tint even against the dimly lit workbench; the outline of the glow follows the shape of the visible cell layer (patchy if the cells are clustered, sheet-like if they form a continuous layer) rather than washing evenly over the whole dish.
level_5: All elements of score 4 are met, and the glow turns on and off within essentially the same moment as the blue light itself in every repetition, with no lag in either direction; the green color stays uniform across all ON frames; nothing else in the scene (dish rim, lid, or any condensation) ever glows, so the cell-confined green emission is the only light change tied to the blue light's switching.

Spatiotemporal Consistency rubric:
level_1: The petri dish or the blue light source is in one place and orientation in a shot, then (with no pan, camera move, or motion shown connecting the two) is in a distinctly different place or orientation in the very next shot; the visible cell layer changes shape or amount abruptly between adjacent frames with nothing shown to explain it; the video cuts to a black frame or otherwise breaks continuity outside of an intended ON/OFF transition; or the room's ambient lighting suddenly shifts (e.g., a bright bench flips to near darkness, or the reverse) for a reason unrelated to the blue light switching on or off.
level_2: The dish shifts position, rotates, or changes apparent size on screen between the ON and OFF portions of a cycle; the blue light's beam angle changes from one cycle to the next with nothing in the scene explaining the change; the shadow cast by the dish rim or the light housing changes direction between frames even though the light source itself does not appear to move.
level_3: Dish remains fixed in position and orientation; light source remains stationary relative to dish; shadows on dish and workbench remain consistent in direction and softness; cells show no motion, displacement, or morphological change across the sequence; lighting transitions occur only at light ON/OFF moments.
level_4: All elements of 3-score are satisfied, AND camera viewpoint is fully static (no pan, tilt, zoom, or focus shift); dish rim and base maintain consistent perspective and occlusion relationship; light beam maintains constant angular incidence across cycles; no inter-frame geometric distortion (e.g., stretching, warping, pixel shearing).
level_5: All elements of 4-score are satisfied, AND parallax between dish features (e.g., rim, bottom, cell clusters) remains physically coherent; specular highlights on dish surface move consistently with light position; no temporal aliasing (e.g., strobing, ghosting, frame duplication); no inter-frame luminance discontinuity outside of intentional ON/OFF transition.