PhOLab 2.0 · Real Olympiad Experiments

PhOLab is a high-fidelity virtual physics laboratory for practicing the rigorous experimental skills required in the International Physics Olympiad (IPhO). The central philosophy is hands-on physical realism: students assemble, align, wire, and read genuine experimental apparatus directly in 3D rather than manipulating arbitrary sliders.

🌐 Live Simulation: https://nlmmr.github.io/pholab/

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Current Experiment

IPhO 2024 E2 — Diffraction from Phase Steps (Parts A, B, C & D)

Faithful interactive recreation of the official optical apparatus from the 54th International Physics Olympiad (Isfahan, 2024):

• Three-Tier Assembly Mechanics:
  • Guided Snap: Assisted assembly with glowing translucent ghost meshes and automatic magnetic alignment.
  • Full Realism: Authentic competition sequence with strict safety interlocks (loosening 4 threaded fastening rods, removing red transport O-rings, peeling cuvette protective adhesive film before pouring, and manual unboxing/storing).
  • Skip Assembly: Instant apparatus presets for rapid physics data collection across Parts A, B, C, and D.
• Procedural PBR Realism:
  • Zero external GLTF assets: procedural knurled knobs with bump/roughness canvas maps, brushed steel vertical posts, anodized aluminum faceplates with official serigraphy, crystal acrylic cuvettes with physical transmission ($IOR = 1.51$), curved liquid meniscus, and high-resolution 2048×2048 circular protractor goniometer.
• Physical Fresnel Diffraction & Speckle:
  • High-precision optical pattern rendering matching Figure 7 of the official IPhO 2024 exam, featuring central phase discontinuity, fringe modulation, Gaussian envelope, and realistic 650 nm laser speckle.
• Calibrated 2D Viewport Overlay Ruler & Caliper:
  • Draggable and rotatable on-screen measurement tool (R hotkey) dynamically calibrated in real time against the Three.js Perspective camera projection (mm/pixel).
• Kinematic & Cabling Dynamics:
  • Procedural flexible Catmull-Rom catenary cables for laser output and 5V USB power bank.
  • Full bidirectional spatial synchronization: moving the observation screen on the bench dynamically recalculates $D = X_{\text{screen}} - X_{\text{laser}}$ and modulates diffraction fringes in real time, while maintaining perfect collinear beam alignment.
• Manual Measurement Notebook:
  • Complete data recording table supporting at least 25 measurements per part, with official IPhO 2024 truth benchmarks.

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Run Locally

npm install --legacy-peer-deps
npm run dev

The laboratory will launch at http://127.0.0.1:3000/.

Automated Verification & Production Build

npm test        # Runs 153 automated tests across physics, state, calibration, primitives, and interactions
npm run build   # Production bundle with zero TypeScript compilation errors

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Architecture

• src/experiments/ipho-2024-e2/: Complete IPhO 2024 E2 experiment implementation (declarative .pholab definition, analytical Fresnel solver, state reducer, and Three.js engine).
• src/core/primitives/: Modular universal physical primitives (SocketPort, FluidMediumContainer, FastenerEntity, HingeEntity, LinearSliderEntity, RotaryDialEntity, DigitalDisplayMesh).
• src/components/: Calibrated HUD tools (HUDOverlayRuler.tsx) and shared 3D controls.
• src/shared/equipment/: Laboratory equipment UI (interactive scientific measurement notebook).

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Official problem source: IPhO 2024 E2 Problem Sheet.