About Geometric Optics
How does a lens or mirror form an image? See how light rays are refracted by a lens or reflected by a mirror. Observe how the image changes when you adjust the focal length of the lens, move the object, or move the screen.
How to play Geometric Optics
Everything is hands-on: drag, click and experiment — the simulation reacts instantly. How does a lens or mirror form an image?
Questions & answers
- What is Geometric Optics?
- Geometric Optics is a free interactive simulation from PhET Interactive Simulations (University of Colorado Boulder) that you can play right in your browser on crumble.lol — no downloads and no sign-up. How does a lens or mirror form an image? See how light rays are refracted by a lens or reflected by a mirror.
- What can kids learn from Geometric Optics?
- It helps kids explore: explain how an image is formed by a converging or diverging lens or mirror using ray diagrams. determine how changing the parameters of the optic (radius of curvature, index of refraction) affects where the image is formed and how it appears (magnification, brightness, and inversion). predict where an image will be formed given the object distance and optic parameters.
- What age is Geometric Optics good for?
- It is designed for middle school (roughly ages 10–14) up to university, and curious kids outside that range can absolutely enjoy poking around it too.
- Is Geometric Optics free to play?
- Yes — Geometric Optics is completely free on crumble.lol and runs fully in your browser on computers and tablets.