Light & least time

Your privacy choices

KiwiBee uses optional Google Analytics, Google Ads, and Meta Pixel cookies to understand adult visitors, measure completed sign-ups, and improve campaigns. Essential cookies always stay on. OpenAI’s ChatGPT Ads Pixel also measures page views and completed enquiries after advertising consent, and may use hashed contact details for matching. Privacy policy

—

About this simulation

Light slows when n increases. The fastest path spends less distance in the slower medium, bending toward the normal. Drag A, B or the golden point P. Sliders also move them.

What students can explore

Move P until A, P and B form a straight line. Then reveal the fastest path.
Set n₂ to 1, then increase it. How does the fastest crossing point move? Match it and compare n sin θ on each side.
Move P to the lowest point of the graph. Are the two angles equal? Direct A-to-B travel is outside this reflected-path comparison.

Learning objectives

1Light does not plan ahead. Add wave contributions: near a stationary path, neighbouring phases change slowly and reinforce. Away from it, phases vary more and tend to cancel.

Questions teachers ask

Is the Light & least time simulation free?

Yes. Open the Light & least time simulation in a modern browser with no download or sign-up required.

Is it suitable for Middle School and High School?

The simulation includes learning-level presets spanning Middle School and High School. Choose the level that matches your class, then use it on a projector or student devices.

Embed this simulation

Drop it into your LMS, blog, or class site — free.

<iframe src="https://kiwibee.io/en/simulations/light-least-time-simulation/embed" title="Light &amp; least time | KiwiBee" loading="lazy" allowfullscreen style="width:100%;height:min(70vh,620px);min-height:420px;border:0;border-radius:16px"></iframe>

Continue exploring

Explore relativistic timing and spacetime diagrams.

—

Explore an adult male reference body in 3D. Reveal 14 anatomical systems, search thousands of named structures, isolate organs, and pull 2,209 modeled pieces apart to see how the body is organized.

—

Explore the head and neck in 3D: 643 source meshes across 14 layers, 47 facial and masticatory muscles, and 77 drawn nerves, vessels and glands the source scan omits. Open any tooth onto its own pulp canal, and follow the seven stages of tooth development.

—