| Source (Luminous) |
Objects that produce their own light. Examples: The Sun (Natural) or an Electric Bulb (Artificial). |
| Path of Light |
Light always travels in a straight line. (Principle: Rectilinear Propagation). |
| Object Types |
Light needs to be blocked by an Opaque object to form a shadow. (Opaque: blocks all light). |
| Shadow Formation |
Requires three essential components: 1. A Light Source. 2. An Opaque Object. 3. A Screen. |
| Umbra |
The darkest inner region of a shadow. This area receives NO light from the source. |
| Penumbra |
The Lighter, outer region of a shadow. This area receives PARTIAL light from the source. |
| Application (Pinhole) |
The Pinhole Camera uses the straight path of light to form an Inverted (upside-down) image. |
| Eclipses |
These are massive shadows cast in space. Solar Eclipse: Moon's shadow hits Earth. |
