Domain: Natural Science — Physics
Target concept: Quinine in tonic water emits fluorescence under ultraviolet light.

Video generation prompt: In a dark room, there are two transparent glass cups: the one on the left contains tonic water, and the one on the right contains regular water. A handheld ultraviolet lamp is directed at both cups, and the light is repeatedly turned on and off.

Evaluation guide:
(i) Target concept: UV-induced fluorescence of quinine in tonic water, requiring photon absorption at UV wavelengths (~365 nm) and re-emission in visible spectrum (~450 nm), with absence of fluorophores in pure water.
Minimum mechanism: Tonic water must contain sufficient quinine to produce detectable blue-white emission under UV excitation; UV lamp must emit in near-UV range; viewing environment must be dark enough to resolve low-intensity fluorescence against background.
(ii)Storyline: [Frame 0–2] Dark room established; two identical transparent cups stationary, left-right labeled by position; [Frame 3–4] UV lamp enters frame, held steadily in front; [Frame 5] Lamp turns ON → left cup instantly emits localized blue-white glow, right cup unchanged; [Frame 6] Lamp turns OFF → left cup glow vanishes completely, right cup unchanged; [Frame 7] Lamp turns ON again → identical left-only glow reappears; [Frame 8–9] Final OFF state confirms complete cessation. All events occur from fixed frontal viewpoint with no camera motion, occlusion, or perspective shift.

Manual:
Experimental Procedure
- Place two identical transparent glass cups side-by-side in a fully dark room: left cup filled with tonic water, right cup with regular water.
- Hold a handheld ultraviolet lamp directly in front of both cups and toggle it ON→OFF→ON repeatedly.
Observation of Experimental Phenomena
- Only the left cup (tonic water) emits visible blue-white fluorescence when the UV lamp is ON; the right cup (regular water) remains dark.
- Fluorescence ceases immediately when lamp is turned OFF; no afterglow or emission in right cup at any time.
Summary of Experimental Principles
- Quinine, a natural compound in tonic water, absorbs ultraviolet light and re-emits it as visible blue-white fluorescence—a photoluminescent process. Pure water lacks such fluorophores and remains non-emissive under UV.

Prompt Grounding rubric:
level_1: No dark room is shown; the two transparent cups are not both visible together; no handheld UV lamp is present; the lamp is never switched on and off during the clip.
level_2: Both transparent cups are visible but are not arranged in a fixed left/right layout at the same time; or the UV lamp appears but is not clearly aimed at both cups; or the room shows visible ambient light rather than darkness; or the lamp is switched on only once with no repeated toggling.
level_3: Two transparent cups sit next to each other in a dark room, one holding tonic water and one holding plain water, matching the left/right layout named in the prompt; a handheld UV lamp is aimed at both cups; the lamp is switched on, off, and on again at least once each; every object and action named in the prompt is recognizably present.
level_4: Everything in the 3-point level holds, and in addition: both cups stay in their original left/right spots for the whole clip; the lamp stays handheld and pointed at both cups through every on/off cycle; nothing blocks either cup or the lamp from view; neither cup nor the lamp is bumped out of position between toggles.
level_5: Everything in the 4-point level holds, and in addition: the tonic-water cup stays unambiguously on the viewer's left and the plain-water cup on the viewer's right in every frame; the lamp is held at the same height, distance, and angle relative to both cups across every toggle; each on-interval and off-interval of the lamp is clean, with the bulb visibly lit only during 'on' spans and visibly dark during 'off' spans.

Scientific and Causal Correctness rubric:
level_1: Neither cup shows any glow at any point; the tonic-water cup and the plain-water cup look identical under the UV lamp; no brightness or color difference appears between the two cups regardless of lamp state.
level_2: A glow appears but is not reliably tied to the tonic-water cup's position, or the same glow shows up in both cups at once, or the glow's color looks nothing like the blue-white typical of quinine fluorescence, or a glow appears even while the lamp is off.
level_3: The tonic-water cup glows with a visible blue-white light whenever the lamp is on and stops glowing whenever the lamp is off; the plain-water cup shows no glow at any point, whether the lamp is on or off; the on/off timing of the tonic-water cup's glow visibly tracks the lamp's on/off state.
level_4: Everything in the 3-point level holds, and in addition: the plain-water cup stays dark through every repeated lamp-on phase, not just the first; the tonic-water cup's glow disappears within a fraction of a second after the lamp switches off, with no lingering afterglow; nothing in the plain-water cup, such as a reflection or glare off the glass, is mistaken for a glow.
level_5: Everything in the 4-point level holds, and in addition: the tonic-water cup's glow turns on and off the same way across every repeated lamp cycle, not just the first one; the plain-water cup shows no visible brightening or color shift during any lamp-on interval, staying as dark as the surrounding room; the glow color stays a consistent blue-white rather than drifting toward violet, cyan, or purple, matching the look of real quinine fluorescence.

Spatiotemporal Consistency rubric:
level_1: Either cup disappears and reappears between frames; the lamp jumps to a new position or angle without visibly moving there; the room brightens or darkens for reasons unrelated to the lamp's on/off state; a cup's shape or transparency changes partway through the clip; a cup's rim or base breaks apart or vanishes.
level_2: A cup drifts sideways or up and down between one toggle and the next; the lamp shakes noticeably or appears to change hands mid-clip; the room's lighting jumps straight to full brightness instead of tracking the lamp turning on; the darkness of the room flickers unpredictably outside of the lamp's on/off cycle; a cup's rim or base flickers or glitches briefly.
level_3: Both cups stay in the same left/right spots for the whole clip; the lamp stays steady in the same hand and pointed the same way through every toggle; the room only brightens when the lamp is on and only darkens when the lamp is off; neither cup changes shape, vanishes, or breaks apart; the room stays uniformly dark apart from the lamp's own light.
level_4: Everything in the 3-point level holds, and in addition: the lamp's motion between toggles is smooth, without jerks, shakes, or a change in grip; both cups keep the same glassy look and transparency throughout; if the lamp casts a visible shadow, that shadow stays consistent in shape and position relative to the cups.
level_5: Everything in the 4-point level holds, and in addition: the motion between frames is smooth throughout, with no stuttering, skipped frames, or repeated frames; the lamp's beam keeps a stable shape when lit, without flaring or pulsing oddly; both cups' outlines stay sharp and unbroken in every frame; no motion blur is heavy enough to make it unclear which cup is which or whether the lamp is on or off.