Do I need to install anything?

No. It runs in any modern browser, free, with no account required.

For Engineers · Snell's Law

Snell's Law for a telescope

Built for engineers using it for real design work. Go from concept to a running model in the browser, then scale to the cloud when needed. Simulate a telescope live below — adjust the inputs and watch it respond, right in your browser.

Snell's Law — RefractionLive

n₁ sin θ₁ = n₂ sin θ₂

Controls

Light bends when it crosses between media. Going into a slower medium it bends toward the normal; going the other way past the critical angle it reflects entirely.

Presets

Incidence angle

Index n₁ (top)

Index n₂ (bottom)

▶ Run in Python

Data Inspector

n₁ → n₂1 → 1.5

Critical anglen/a

Snelln₁sinθ₁ = n₂sinθ₂

Governing equation

n_{1} sin θ_{1} = n_{2} sin θ_{2} : 1 sin 4 0^{\circ} = 1.5 sin θ_{2}, θ_{c} = arcsin \frac{n _{2}}{n _{1}} = n/a

Reading this result: Into a denser, slower medium: the ray bends toward the normal, so the refracted angle is smaller than the incidence angle.

Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.

or unlock everything with Pro →

Also for:Students Researchers Educators Hobbyists & Makers K-12 Students First Responders General version →

More with Snell's Law

Snell's Law for a camera lens Snell's Law for a laser beam Snell's Law for a fiber-optic cable Snell's Law for a microscope Snell's Law for a prism Snell's Law for a rainbow Snell's Law for a hologram Snell's Law for a solar cell

Frequently asked questions

Is this good for engineers?: Yes — this version of "Snell's Law for a telescope" is framed for engineers using it for real design work. Go from concept to a running model in the browser, then scale to the cloud when needed.
Do I need to install anything?: No. It runs in any modern browser, free, with no account required.