Domain: Engineering — Optical Engineering
Target concept: Newton's Rings Experiment

Video generation prompt: Place the Newton's rings experimental setup (a plano-convex lens + a flat glass plate) under a monochromatic green light source (λ = 550 nm), adjust the setup to ensure normal incidence of light, observe the interference pattern through a reading microscope, mark the bright rings in green, the dark rings in black, and the central dark spot in red.

Evaluation guide:
(i) Target concept: Optical interference in a variable-thickness air wedge formed between plano-convex lens and flat glass plate under monochromatic illumination.
Minimum mechanism: Physical contact between lens and plate must create a radially symmetric air gap increasing as r²; green light must be coherent enough to produce stable fringes; reflection phase shift at lower interface must induce destructive interference at center.
(ii)Storyline: Frame 1–2: Flat glass plate stationary in view. Frame 3–4: Plano-convex lens lowered into view and settles onto plate; contact established with no bounce or slide. Frame 5–6: Green light activates; uniform illumination appears, no glare or hotspot dominance. Frame 7–8: Microscope comes into focus; ring pattern emerges from center outward, starting with central red spot, then first dark ring, then first bright green ring, continuing concentrically. Frame 9–10: Fully resolved pattern stabilized: all rings continuous, colors fixed, no motion blur, no parallax shift; central red spot visually distinct by hue only, not brightness.

Manual:
Experimental Procedure
1. Place flat glass plate horizontally on optical bench.
2. Gently place plano-convex lens (convex side down) onto plate to form air wedge.
3. Illuminate assembly from above with monochromatic green LED (λ=550 nm).
4. Position reading microscope vertically above center and focus on interference pattern.
Observation of Experimental Phenomena
- Concentric circular interference rings visible.
- Bright rings appear green, dark rings appear black.
- Central contact spot appears red (distinct hue, same intensity as dark rings).
Summary of Experimental Principles
- Newton's rings arise from interference between light reflected from air wedge interfaces.
- Central dark spot results from π phase shift on reflection at glass-air boundary.
- Ring radii follow rₘ ∝ √m due to parabolic air gap profile.

Prompt Grounding rubric:
level_1: None of the four required setup elements - the plano-convex lens, the flat glass plate, the monochromatic green light source, and the reading microscope - is visible anywhere in frame; there is no ring pattern and no central spot of any kind.
level_2: Between one and three of the four required setup elements (plano-convex lens, flat glass plate, monochromatic green light source, reading microscope) are visible, with at least one of the four missing or unidentifiable; no discernible concentric ring pattern or central spot appears, regardless of which of the elements are present.
level_3: Full setup present: plano-convex lens in contact with flat glass plate, green light source illuminating from above, reading microscope positioned above the setup; ring pattern visible with a central region, but the ring color coding (bright green / dark black / central red) is fully absent or incorrectly assigned.
level_4: All setup elements present and spatially coherent: plano-convex lens resting on flat glass plate under green illumination, reading microscope aligned vertically above; ring pattern visible with correct spatial hierarchy (concentric circles), and a central spot present - but exactly one of the three required colors is incorrect (e.g., the central spot is black instead of red, or the bright rings are white instead of green, or the dark rings are gray instead of black).
level_5: All setup elements present and correctly arranged: plano-convex lens in direct contact with flat glass plate, monochromatic green light source visibly illuminating from above, reading microscope fixed in vertical alignment above the center; concentric ring pattern clearly visible with bright rings appearing uniformly green, dark rings appearing uniformly black, and the central spot appearing uniformly red - no deviation in object type, placement, quantity, shape, or assigned color.

Scientific and Causal Correctness rubric:
level_1: No interference phenomenon is visible; the pattern is random, radial, spiral, or otherwise non-concentric; the central region is absent or not distinguishable; all rings share the same brightness/color; there is no contrast between bright, dark, and central regions.
level_2: A concentric circular pattern is visible but lacks the correct contrast hierarchy: either no dark rings, no bright rings, or no central spot appear; or all rings share an identical color (e.g., all green or all gray); or the central spot matches the surrounding ring color instead of differing from it.
level_3: A concentric ring pattern is present with alternating bright and dark bands and a distinct central region; bright rings are green, dark rings are black, and the central spot is red - but at least one causal violation is present: e.g., bright rings appear where dark rings should be (a phase-reversal misrepresentation), or the ring spacing increases moving outward (violating the sqrt(m)-dependent spacing of Newton's rings, where spacing should narrow, not widen, toward the periphery).
level_4: The concentric ring pattern shows the correct alternating contrast (bright/dark), correct color assignment (green/bright, black/dark, red/central), and correctly decreasing ring spacing toward the periphery - but the central spot is red AND bright (violating the destructive-interference condition expected there for normal incidence on the air wedge), OR the bright rings appear discontinuous or fragmented while the dark rings remain continuous (breaking the expected symmetry of the interference pattern).
level_5: The concentric ring pattern shows strictly alternating bright (green) and dark (black) bands with continuously decreasing spacing between rings moving outward from the center; the central spot is uniformly red AND dark (matching the intensity of the surrounding dark rings, distinguished only by hue); no ring shows distortion, breakage, or irregularity; every visual feature is consistent with destructive interference at the center and constructive interference at the radii where the air-gap path difference equals a whole number of wavelengths.

Spatiotemporal Consistency rubric:
level_1: The plano-convex lens or the flat glass plate vanishes from view in one frame and reappears in a different position in the next, with no continuous motion connecting the two; the reading microscope's view jumps sideways with no visible panning; the green illumination goes from fully dark to fully lit within a single frame with no fade-in; the ring pattern appears fully formed in one frame with no earlier frame showing a partially formed pattern; the central red spot is visible before the lens has made contact with the plate.
level_2: At least two of the following occur: the lens and plate are not shown in persistent contact across frames (the gap between them appears to open and close); the green illumination switches on and off erratically rather than staying lit once activated; the microscope's viewpoint jumps horizontally or vertically between frames; the ring pattern appears fully formed in the very first frame it is shown, without any frame showing it growing outward; the central red spot changes size abruptly with no gradual scaling.
level_3: Only minor spatiotemporal flaws remain: the lens and plate stay in contact, the green illumination stays steady, the microscope's viewpoint stays fixed, and the ring pattern grows outward from the center progressively - but one flaw is present, such as: the central spot's color briefly flickers before settling, or one ring briefly disappears and then reappears identical to before, or the plate's surface briefly shows a shadow distortion that does not persist.
level_4: The lens stays centered on the plate and the microscope stays vertically aligned throughout, with no drift between them; the green illumination stays uniform and steady; the ring pattern grows smoothly outward with no ring appearing or disappearing partway through; the central spot stays stable in position, size, and hue - but one small violation remains, such as a brief specular highlight passing across the lens surface, or a brief, slight desaturation of the green rings that quickly resolves.
level_5: No spatiotemporal artifacts remain: the lens and plate stay in uninterrupted contact throughout; the green illumination holds the same intensity and comes from the same direction the whole time, with no dimming, brightening, or shift in the light's apparent source; the microscope's viewpoint stays completely fixed with no drift, shake, or parallax shift; the ring pattern grows outward frame by frame with strictly increasing radius and no ring skipped or duplicated; the central spot appears at the same moment as the first dark ring and stays stable in position, size, hue, and brightness for the remainder of the sequence.