PhysX — Interactive Gravitational Lensing Visualizer

Overview

PhysX is a small educational app that simulates gravitational lensing by integrating tiny light-ray deflections from massive objects (black holes). The app is designed for exploration and teaching — change parameters and see how lensing patterns evolve.

Controls

• Space: Pause / Resume
• R: Reset rays
• B: Add a black hole at the center
• Use the control dock to change Black Hole Mass, Number of Light Rays, and Simulation Speed.
• Use the Ray Palette to pick presentation-friendly ray colors and press Apply Palette.
• Use the Presets (Strong Single / Binary) or run the Guided Tour from the controls for quick demos.
• Open the Learn dock for a short guide and references, and enable Teaching Mode in the controls to show per-black-hole predictions and HUD annotations.

Educational Notes

• The primary formula shown is α = 4GM / (c^2 b), which is the small-angle deflection by a point mass (α in radians).
• The simulation accumulates small deflections as light rays pass near massive objects to produce curved paths.
• Try increasing the number of rays and mass to see strong lensing patterns appear.

Install

Create a virtual environment and install dependencies:

python -m venv .venv
.venv\Scripts\activate  # Windows
pip install -r requirements.txt

Run

Start the app:

python app.py

Repository readiness

• Added .gitignore, requirements.txt, LICENSE (MIT), CONTRIBUTING.md, and a basic GitHub Actions workflow (.github/workflows/ci.yml) that runs a smoke test (import app).

License & Credits

This project is available under the MIT license. See LICENSE for details.