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Basketball Phases Simulator
Imagine a lamp (the Sun) and a basketball (the Moon). Walk around the ball and the lit shape matches the Moon in the sky.
Looks like Full Moon from Earth
Before you start
A lamp and a basketball in a dark room is the original classroom demo. This lab copies that geometry.
Key idea
The ‘phase’ is just which part of a ball is lit as you walk around it.
What you see
- Lamp (Sun), basketball (Moon), and your eye
- Matching Moon disk underneath
Try this
- Play the orbit and stop when the basketball looks like first quarter
- Stand (in your mind) at the eye marker
Common mistakes
- Putting the basketball between you and the lamp and calling that full moon
Glossary
- Phase
- Shape of the sunlit part as seen by an observer.