Lesson 8 of 10
💡 Light & Shadows
What You'll Learn
- Understand that light travels in straight lines
- Explain how shadows form and why they change
- Distinguish between transparent, translucent, and opaque materials
How Light Travels
Light travels in straight lines called rays. It travels incredibly fast — about 186,000 miles per second! When light hits an object, three things can happen:
- 🔥 Absorbed — the object soaks up the light (dark objects absorb more)
- 💥 Reflected — the light bounces off (mirrors, white surfaces)
- 🔍 Transmitted — the light passes through (glass, water)
Materials are classified as:
- 🔍 Transparent — light passes through clearly (glass, clear plastic)
- 🔋 Translucent — some light passes through, but scattered (wax paper, frosted glass)
- ⬛ Opaque — no light passes through (wood, metal, your hand)
How Shadows Form
A shadow forms when an opaque object blocks light. The shadow is always on the opposite side from the light source.
Shadow size depends on the angle of the light: when the light source is directly above, the shadow is short; when the sun is low (early morning or late afternoon), shadows are long.
💡 Virtual Lab: Shadow Simulator
Move the sun angle slider to simulate time of day. Watch the shadow length and direction change!
🌅 Dawn
🌈 Dusk
Quick Check
When is your shadow the shortest?
A window is an example of a ___ material.