Domain: Natural Science — Geology & Geophysics
Target concept: The pointer of the handheld analog magnetometer deflects when a bar magnet approaches.

Video generation prompt: On the table, a handheld analog magnetometer with a visible pointer remains stable, while a red-and-blue striped bar magnet is brought close to it from the side, moved away, and then flipped once (180°); the whole approach–move-away–flip sequence is then repeated once more.

Evaluation guide:
(i) Target concept: Magnetic torque on a freely pivoted magnetic dipole (compass needle) in an external non-uniform field.
Minimum mechanism: Needle must be magnetized, suspended with low friction, and responsive to field direction; bar magnet must possess stable dipole moment with red=north, blue=south; field gradient must exist (i.e., magnet cannot be infinitely far or perfectly centered).
(ii)Storyline: Frame 0–t₁: Stable baseline, magnetometer centered, pointer motionless, bar magnet off-screen or static at lateral distance. t₁–t₂: Bar magnet enters from side and moves laterally inward → pointer begins smooth, continuous swing toward approaching pole. t₂–t₃: Bar magnet moves laterally outward → pointer smoothly returns toward center. t₃–t₄: Bar magnet rotates 180° in place (no translation) → pointer smoothly reverses direction. t₄–t₅: Pause (stillness) → pointer holds new orientation. t₅–t₆: Second identical cycle begins. All phases observed from fixed frontal/slightly angled viewpoint ensuring full visibility of pointer, dial, and bar magnet side profile; no occlusion; consistent lighting and background.

Manual:
Experimental Procedure
1. Place handheld analog magnetometer with visible pointer flat and motionless on table.
2. Hold red-and-blue striped bar magnet at arm’s length to the side of the magnetometer.
3. Slowly bring bar magnet laterally toward the magnetometer until near (but not touching).
4. Slowly move bar magnet laterally away to original distance.
5. Rotate bar magnet 180° around its vertical axis (flipping red↔blue ends) while keeping position fixed.
6. Repeat steps 3–5 once more.
Observation of Experimental Phenomena
- Pointer deflects toward approaching magnet end during step 3.
- Pointer returns toward center during step 4.
- Pointer reverses direction during step 5 (flip).
- Same deflection pattern repeats identically in second cycle.
Summary of Experimental Principles
The pointer of the handheld analog magnetometer deflects when a bar magnet approaches — due to interaction between the magnetometer’s internal compass needle (a magnetic dipole) and the external magnetic field produced by the bar magnet. Deflection direction depends on pole orientation and distance, confirming magnetic field vector dependence.

Prompt Grounding rubric:
level_1: Neither the handheld analog magnetometer with its pointer nor the red-and-blue striped bar magnet appears; or they appear in separate shots rather than together; or the magnetometer has no visible pointer; or the bar magnet isn't red-and-blue striped; or no approach/move-away/flip motion is implied at all.
level_2: The magnetometer with its pointer and the striped bar magnet both appear together, but the sequence is broken or reordered: only an approach happens with no move-away or flip, the flip is replaced by some other motion (e.g., moving the magnet straight up, or spinning it about its long axis), or the magnet is held facing the front of the device instead of approaching from the side.
level_3: The magnetometer sits still on the table with its pointer visible; the striped bar magnet approaches from the side, moves back away, and is flipped 180° once, all three steps happening from the side and in that order within the 10-second span of the clip.
level_4: Everything required for score 3 is present, and the whole approach–move-away–flip sequence repeats a second time; both passes keep the magnet approaching from the side (never frontally or from above); the magnetometer stays visible and still on the table throughout; the bar magnet's red-and-blue stripe pattern and orientation stay consistent across both passes.
level_5: Everything required for score 4 is present, and both passes are alike in every way that matters: the same side is used for the magnet's approach both times, the red-and-blue stripes never appear twisted or hidden, the pointer only visibly moves during the approach and flip phases (staying still during move-away), and nothing extraneous (a shaking hand, the magnetometer sliding, a camera refocus) intrudes.

Scientific and Causal Correctness rubric:
level_1: The pointer never moves at all; or it swings in the wrong direction (e.g., toward the magnet during move-away, when it should be returning to center); or it moves continuously with no relation to the magnet's motion; or it moves while the magnet is sitting still; or the bar magnet shows no red/blue stripes; or the device shown is a digital readout rather than one with a visible mechanical pointer.
level_2: The pointer moves, but only during the move-away or only while the magnet sits still, never during the approach; or its direction contradicts the magnet's polarity (e.g., the blue end leads the approach but the pointer swings away from the magnet instead of toward it); or it keeps deflecting after the magnet has been fully withdrawn; or the red and blue stripes don't correspond to the correct poles (red should mark the north-seeking end).
level_3: The pointer swings toward the approaching end of the bar magnet during the approach, returns toward center during the move-away, and swings the opposite way during the 180° flip; the magnet's red stripe corresponds to its north pole and blue to its south pole; the pointer's swing visibly grows as the magnet gets closer, without any specific numeric claim being made.
level_4: Everything required for score 3 is present, and the pointer's direction reverses again during the second flip (undoing the first reversal), the pointer swings toward whichever colored end is nearer during both approaches, and it returns to center and stays there while the magnet is fully withdrawn and still between the two cycles.
level_5: Everything required for score 4 is present, and the pointer's swing direction visibly tracks the magnet's rotation continuously as it flips (reversing gradually in step with the magnet's 180° turn rather than jumping abruptly only once the flip is complete), and the pointer settles into only three recognizable resting states (centered, deflected toward the red end, deflected toward the blue end) with no unexplained extra positions.

Spatiotemporal Consistency rubric:
level_1: The magnetometer or the bar magnet vanishes and reappears, changes size or orientation with no motion connecting the two states, or is visibly torn apart (pointer snapping off, casing cracking); or the lighting flashes or strobes; or the camera cuts, zooms, or pans mid-sequence; or the tabletop flickers or warps.
level_2: The pointer becomes fully hidden for a noticeably long stretch during a phase where it should be visible (e.g., blocked by the magnet during the approach); or the magnetometer visibly slides on the table with no hand touching it; or the magnet's flip looks jerky, with visible starts and stops mid-rotation; or the pointer's motion looks like it's skipping instead of sweeping smoothly.
level_3: The magnetometer stays fixed in position and orientation on the table; the bar magnet moves smoothly along its approach/retreat path and rotates smoothly during the flip; the pointer moves continuously between its resting positions with no visible skips; the pointer is never hidden during a phase where it needs to be seen; the lighting, shadows, and camera framing stay consistent.
level_4: Everything required for score 3 is present, and the motion is spatially coherent: the approach and move-away happen along the same line in opposite directions, the flip happens in place with no sideways drift, the pointer's arc of motion looks like it's pivoting naturally rather than bending or detaching, and the tabletop's texture and reflectivity stay consistent throughout.
level_5: Everything required for score 4 is present, and the pacing feels uniform within each phase: both approaches happen at a similar speed, both move-aways happen at a similar speed, both flips rotate at a similar speed, and no single deflection event (either approach) shows an obviously longer or shorter delay before the pointer starts moving than the others.