Light can interact with materials in several ways, depending on the light’s wavelength and the material’s properties. The main interactions are:
- Reflection
- Light bounces off the material’s surface.
- Specular reflection (smooth surfaces like mirrors) keeps the image clear.
- Diffuse reflection (rough surfaces) scatters light in many directions.
- Absorption
- Light energy is taken in by the material, often converted to heat or used in chemical reactions (e.g., photosynthesis).
- Dark objects absorb more light than light-colored ones.
- Transmission
- Light passes through the material.
- Transparent materials (clear glass) let light through with little scattering.
- Translucent materials (frosted glass) transmit light but scatter it, blurring images.
- Refraction
- Light bends when entering a medium with a different optical density, due to a change in speed.
- Example: A straw in water looks bent at the surface.
- Scattering
- Light is redirected in different directions by particles or irregularities in the material.
- Example: The blue sky results from Rayleigh scattering of sunlight by air molecules.
- Diffraction and Interference
- Light bends around edges or through tiny openings, sometimes producing colorful patterns (like on CDs or soap bubbles).