A Math Museum interactive exhibit
dy/dt

Differential Equations

If an equation tells us how a system changes right now, can we use it to predict the future?

Room 1

Equations That Describe a Future

An ordinary equation tells you what something is. A differential equation tells you how it is changing—and asks you to reconstruct what happens next.

1600s

Calculus makes motion writable

Newton and Leibniz create tools for expressing velocity, acceleration, growth, and changing quantities.

1700s

Euler turns change into a method

Euler develops systematic ways to approximate solutions step by step.

1800s–today

The language of models

Differential equations become central to engineering, biology, economics, weather, circuits, and nearly every part of physics.

Room 2

A Map Made of Slopes

A differential equation may not draw the solution directly. Instead, it tells the slope the solution should have at every point.

Click anywhere in the field to place a starting point and trace one possible solution.

Room 3

Euler's Method: Follow the Local Slope

Start at a known point. Move a little, use the slope there, then repeat. Smaller steps create a more faithful prediction.

Approximate y at x=4
Exact value
Error
Room 4

A Spring Remembers Motion

A spring's acceleration depends on how far it is stretched. Add damping, and the motion slowly loses energy.

position″ + damping · position′ + stiffness · position = 0
Room 5

Cooling, Growth, and Saturation

The same broad idea—change depends on the current state—creates very different futures.

Room 6

The Equation Is a Rule, Not Just an Answer

A differential equation can produce steady growth, oscillation, decay, equilibrium, or instability depending on its structure and starting conditions.

Initial conditions

The same rule can create different paths depending on where the system begins and how fast it is already moving.

Order

A first-order equation tracks one layer of change. A second-order equation can include acceleration and therefore needs more starting information.

Linear vs. nonlinear

Linear systems combine neatly. Nonlinear systems can bend, saturate, couple, and sometimes become chaotic.

Closed form vs. numerical

Some equations have exact formulas. Many important ones can only be explored with numerical approximation.

Final Room

The Idea Continues

dy/dt

The symbol is only the doorway. The real exhibit is the connection it reveals.

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