Tap a piece to see what the light does there.
Add a piece
Light
Start with
How to play
- Drag a lens, mirror or prism into the light. Drag the light too.
- Drag the little round handle to turn a piece (or use the Turn buttons).
- Tap a piece to see the angle the light goes in and comes out.
| Do this | Phone | Keyboard |
|---|---|---|
| Pick a piece | Tap it | N next (on the bench) |
| Move it | Drag it | Arrows (Shift = faster) |
| Turn it | Drag its handle, or Turn | Q / E (Shift = finer) |
| Remove it | Remove button | Delete |
| Change the light | Light buttons | L |
What's happening?
- Light slows down in glass. When it hits glass at a slant, it bends. That's refraction (Snell's law).
- A mirror bounces light off at the same angle it came in.
- A convex lens bends parallel light to meet at one spot, the focal point (F). A concave lens spreads it out.
- Glass bends violet light a bit more than red. So a prism fans white light out into a rainbow.
- Going from glass into air at a steep angle, light can't get out at all. It bounces back inside: total internal reflection. Internet cables (optical fibres) work this way.
Try this: load Lenses and drag the concave lens until the beam comes out parallel again. Where is it compared with the two F marks?