Meet
Ibn al-Haytham
Say it: ib-un al-HAY-thum
Their story. Your next idea.
In Cairo, Ibn al-Haytham spent time under house arrest. He used that time at home to study light through hundreds of experiments. Some thinkers said that eyes send out rays. Ibn al-Haytham tested this idea and explained that light reflects off objects and enters our eyes.
Lost Islamic History, p. 91 · 1001 Inventions, p. 55
opticsthe study of light and seeing
reflectto bounce off a surface
experimenta careful test of an idea
YOUR TURN · 10 MINUTES
Make a tiny light laboratory
A flashlight, three pieces of card, sticky tack, and a grown-up.
- Ask a grown-up to make a small hole in each card.
- Stand the three cards upright with the holes in a row. Place a flashlight behind the first card.
- Try to shine the light through all three holes onto a wall.
- Move just the middle card. Predict what will happen, then try it. Draw what you notice.
Use a flashlight, never a laser. Do not shine light into anyone’s eyes or look at the sun.
Let’s wonder
How could you test an idea about light at home?
My next question: __________________________________________________