An interactive engineering playground

Engineering
Candy

Engineering you can experiment with — set it, break it, watch it solve.

Textbooks tell you the answer. This place lets you find it — and lets you get it wrong. Every topic here is a live sandbox: the governing equation, the method that solves it, and a set of controls so you can push on the physics and see what gives. It's for anyone curious about how engineering phenomena actually behave — whether you know the equations cold or are simply curious enough to start experimenting.

So don't just read about it — play with it. Drag a slider, break a boundary condition, drive a system into resonance, and watch the equations answer back in real time. Every lab is a place to experiment, and there are always more on the way.

Play.

Interactive labs where you set the conditions, push on the physics, and watch the equations respond live.

📖

Learn.

Textbook-style companion pages — the derivation, the equations, the method — for the why behind the knobs.

🍬

Collect.

Candy Cards & printable formula sheets — a different candy theme for every topic, to keep and review.

📓

Notebooks.

Your own green-quadrille engineering notebook — take notes, sketch, and keep them, right in your browser.

Heat Transfer

Conduction● live

2D Steady-State Conduction

Set the temperature on four walls — or insulate them — add internal heat, and watch a plate relax to steady state by the same relaxation the computer uses. Find out when the problem has no answer at all.

◈ Live SOR solver▶ Animated⚠ Break-it mode
Open the lab →
Conduction● live

Transient Conduction

Quench a hot slab and watch the temperature ride inward over time. Lumped capacitance, the Biot number, and the exact moment the simple model starts to lie.

▶ Animated quenchBiot & Fourier no.Lumped vs. real
Open the lab →
Convection● live

Convection & Boundary Layers

Blow fluid over a hot surface and grow the thermal boundary layer. Reynolds, Prandtl, Nusselt — and the moment laminar trips into turbulence.

▶ Animated flowRe · Pr · NuTransition
Open the lab →
Radiation● live

Thermal Radiation

Heat a surface and watch its spectrum slide from infrared toward visible. Planck, Wien, Stefan–Boltzmann — then trade photons between two gray surfaces.

Planck curveσT⁴Net exchange
Open the lab →

Math Methods

Series● live

Fourier Series Builder

Stack sines until a square wave appears. Drag the number of terms, watch the Gibbs overshoot refuse to die — then flip to the spinning-circle phasor view.

▶ Build up⊙ PhasorsSpectrum
Open the lab →
ODEs● live

Phase Portraits & Direction Fields

Click anywhere to drop a trajectory onto a vector field and watch it flow. Eigenvalue classification, saddles & spirals, plus nonlinear classics with limit cycles.

Click to traceEigenvaluesNonlinear
Open the lab →
PDEs● live

The Heat & Wave Equations

Separation of variables, made visible. Pluck a string or heat a rod and watch the modes evolve — one equation forgets, the other remembers.

▶ AnimatedHeat vs. waveModal spectrum
Open the lab →
Homework mode● live

Custom Fourier & PDE Solver

Bring your own function. Type any f(x), pick a sine/cosine/full series, read off the coefficients, then send it into the heat or wave equation. Built for checking real PDE homework.

Your own f(x)Coefficients→ solve PDE
Open the lab →
ODE + Series● live

The Auto-Tuner

Drive a damped oscillator with a square or sawtooth wave decomposed into Fourier harmonics. Each one passes through the transfer function — and one landing near resonance can dominate the rest.

SuperpositionHarmonic spectrumSelective resonance
Open the lab →

Vibrations & Dynamics

Vibrations● live

The Spring–Mass–Damper

The one system to rule them all. Pluck it and watch it ring down, or drive it with a shaker, tune mass, stiffness and damping, and cross into resonance.

▶ Real-timeResonanceFree & forced
Open the lab →
Dynamics● live

Frequency Response & Bode Plots

Sweep the forcing frequency and trace the Bode magnitude and phase. Watch input and output sinusoids scale and slip out of step — where machines shake themselves apart.

Bode mag & phaseLive in/outQ factor
Open the lab →

Numerical Methods

Root finding● live

Root Finding & Fixed-Point Iteration

Newton, secant, and fixed-point iteration hunting a root. Watch the cobweb staircase converge — or fly off, when the same equation is rearranged the wrong way.

▶ Cobweb plotType your g(x)Convergence test
Open the lab →
ODEs● live

ODE Solver — Slope Fields & RK4

Type y′ = f(x, y), see the direction field, click to drop an initial condition, and race Euler against Runge–Kutta — with a mini ODE textbook alongside.

▶ Slope fieldsEuler vs RK4📖 Learn
Open the lab →
Linear systems● live

Gauss–Seidel & Jacobi

Solve a linear system by iteration — watch it converge sweep by sweep, or diverge when the matrix isn't diagonally dominant. Includes a heated-fin and a circuit system to play with.

▶ Iterate liveConvergence plotWorked systems
Open the lab →

Games

Fourier● live

Match the Mystery Wave

A secret wave hides on screen, built from pure harmonics. Dial in the sliders to land on top of it, climb the match meter, and earn your stars. Fourier decomposition, by feel.

🎲 Match & score⭐ Stars🎉 Levels
Play the game →
More gamessoon

Classify the Fixed Point · Make It Converge

A phase-portrait quiz against the clock, and a linear-algebra puzzle where you swap rows to make the system converge. On the way.

QuizPuzzle

Dedication

Dedicated to my doctoral advisor, Dr. Edward Lumsdaine, whose joy in teaching and gift for sparking creativity in his students is the spirit this site hopes to carry forward.