The model treats light as straight rays in a uniform medium and the source as a single point. Geometric projection gives magnification as the ratio of source-to-screen to source-to-object distances. The result depends on relative positions, not an object growing. Diffraction, scattering and an extended source's penumbra require richer models.
Light, sound and electricity · Discover & try
What makes a shadow bigger?
Reading level 5 of 5 · AdvancedChange
Word help
opaque
Not letting the model light pass through.
ray
A line representing the direction light travels.
Watch · Try · Explain
See how it works
The interactive activity is loading.
Point-source projection; sharp edges and distances are idealised, not a real lamp measurement.
What to look for
- Edge rays continue straight
- The object keeps its own size
- A closer object makes a wider projection
Explain what you noticed
A fixed screen is 6 units from a point lamp. A 1-unit object moves from 3 units to 2 units from the lamp. What happens?
Keep this idea: A shadow can change size without its object changing size.
Follow the sources
Source material checked 2026-10-29. Explanations and activities by Nepedia. Source links do not imply endorsement.
Keep following the idea
Next discovery →