A native macOS application featuring 11 interactive physics demonstrations inspired by the work of Sir Isaac Newton. Built entirely with SwiftUI and Canvas rendering, running natively on Apple Silicon with zero external dependencies.
The legendary moment that sparked Newton's theory of gravitation. Features a gravitational field visualization with directional arrows, a bouncing apple with adjustable Earth mass, force vector display, and a stick-figure Newton sitting under the tree. Click or press Space to drop the apple.
Newton's famous 1666 experiment decomposing white light through a glass prism. Uses Snell's Law with wavelength-dependent refractive indices (Cauchy's equation) to accurately model how different colors of light refract at different angles. Adjustable prism angle and beam position with labeled spectrum output.
Interactive visualization of how gravitational (and light) intensity decreases with the square of distance. Features animated expanding wavefronts, area panels showing how force spreads, and a real-time graph comparing 1/r^2 vs 1/r falloff curves.
Classic conservation of momentum demonstration with 5 chrome-rendered pendulum balls. Includes preset configurations (1-ball, 2-ball, 3-ball, opposing), drag interaction, V-shape strings, metallic ball shading, and an energy conservation readout. Physics uses substep integration for stability.
N-body gravitational simulation implementing Newton's Law of Universal Gravitation. Three presets:
- Solar System: Sun with Mercury through Jupiter
- Binary Star: Two co-orbiting stars with a circumbinary planet
- Lagrange Points: Sun-Earth system with L4/L5 Trojan asteroids
Features orbital trails, velocity vectors, adjustable time scale, and a deterministic star field background.
Tabbed demonstration of all three Newtonian laws:
- First Law (Inertia): A puck on a frictionless vs. rough surface
- Second Law (F = ma): Adjustable force and mass with real-time acceleration calculation
- Third Law (Action-Reaction): Elastic collision with visible equal-and-opposite force arrows
Newton's 1704 arrangement of the seven spectral colors into the first color wheel. Spin the wheel to see colors merge toward white, demonstrating that white light is a combination of all spectral colors. Features wavelength labels, adjustable speed, and sector display.
Interactive function plotter with derivative and integral visualization. Four selectable functions (x^2, sin(x), x^3-x, Gaussian). Features:
- Draggable tangent line showing instantaneous slope
- Derivative curve overlay (dashed orange)
- Riemann sum integral visualization with adjustable rectangle count (2-100)
Launch projectiles at configurable angles and speeds under gravity. Displays theoretical range, max height, and flight time. Compare trajectories with and without air resistance. Toggle the optimal 45-degree reference arc. Each launch gets a unique color for easy comparison.
A particle fountain demonstrating F = ma with hundreds of simultaneous particles. Particles launch upward and fall under adjustable gravity, with optional wind force. Three color modes: velocity-based, height-based, or rainbow. Toggle velocity vectors to see acceleration in action.
Newton's Law of Cooling: T(t) = T_env + (T_0 - T_env) * e^(-kt). Real-time exponential decay graph with temperature-colored data points, a thermometer visualization, and adjustable parameters (initial temperature, room temperature, cooling rate k). Optional linear cooling comparison shows why exponential decay is the correct model.
Requirements:
- macOS 15 (Sequoia) or later
- Swift 5.10+ / Xcode 16+
- Apple Silicon or Intel Mac
# Clone and open in Xcode
git clone https://github.com/christyrrell/Newton.git
open Newton/Newton.xcodeprojThen press ⌘R to build and run, or build from the command line:
cd Newton
xcodebuild -project Newton.xcodeproj -scheme Newton -configuration Release build- Sidebar: Click any demo to switch between demonstrations
- Info Panel: Press
ior click the info button to show/hide the description panel - Each demo has its own interactive controls in the bottom bar
Newton/
Newton.xcodeproj/ # Xcode project
Newton/ # App source code
NewtonApp.swift # @main App entry point
ContentView.swift # NavigationSplitView with sidebar
Assets.xcassets/ # Asset catalog (icons, colors)
Newton.entitlements # App sandbox entitlements
Models/
Demo.swift # Demo enum with metadata and descriptions
Views/
FallingAppleView.swift # Gravitational field + falling apple
PrismView.swift # Light dispersion through a prism
InverseSquareView.swift # 1/r^2 law visualization
CradleView.swift # Newton's Cradle pendulums
OrbitsView.swift # N-body orbital simulation
ThreeLawsView.swift # All three laws of motion
ColorWheelView.swift # Newton's colour circle
CalculusView.swift # Derivatives and integrals
ProjectileView.swift # Projectile trajectory simulator
ParticleGravityView.swift # Particle fountain with gravity
CoolingView.swift # Exponential cooling curve
Helpers/
WavelengthColor.swift # Visible spectrum color + refraction
All demos use SwiftUI Canvas for high-performance 2D rendering at 60fps. Physics simulations run using TimelineView for animation timing. No external dependencies required.
The simulations implement real physics:
| Law/Equation | Formula | Used In |
|---|---|---|
| Snell's Law | n1 sin(theta1) = n2 sin(theta2) | Prism |
| Cauchy's Equation | n(lambda) = A + B/lambda^2 | Prism |
| Universal Gravitation | F = G * m1 * m2 / r^2 | Orbits, Falling Apple |
| Inverse Square Law | F proportional to 1/r^2 | Inverse Square |
| Pendulum Dynamics | alpha = -g/L * sin(theta) | Cradle |
| Elastic Collision | m1v1 + m2v2 = m1v1' + m2v2' | Cradle, Three Laws |
| Newton's Second Law | F = ma | Three Laws, Particles |
| Projectile Motion | R = v0^2 * sin(2*theta) / g | Projectile |
| Numerical Integration | Midpoint Riemann sums | Calculus |
| Exponential Decay | T(t) = T_env + (T0 - T_env) * e^(-kt) | Cooling |
Built entirely by Claude Opus 4.6 as an autonomous creative coding project demonstrating native macOS development with SwiftUI.
Inspired by Sir Isaac Newton (1643-1727), whose contributions to mathematics, optics, and physics laid the foundations of modern science.
"If I have seen further, it is by standing on the shoulders of giants." -- Isaac Newton, 1675