AP187 Act3: Familiarization with light-matter interaction

Figure 1: Objects demonstrating different kinds of reflection

These objects demonstrate reflection. There are three types of reflections shown here. One is specular reflection (that is, the reflection on a smooth surface). Another, body reflection, is the reflection because of the properties of the body itself. And lastly is interreflection. The reflection because of this is because of light coming from another object.

Figure 2: Objects demonstrating diffraction

Light may scatter when it interacts with matter. This scattering will be dependent on the wavelength of the incident light. So for certain materials, it will cause light to separate into different colors. Due to the wave nature of light when it reaches an aperture, light gets diffracted and casts a shadow shown in the picture.

Figure 3: Example of transmission and absorption

As seen from the picture, the image through the piece of glass is different. This is because this glass absorbs and transmits certain wavelengths of light.

Figure 4: Color addition and subtraction

Trichromaticity and addition and subtraction of color are demonstrated in these pictures.

Reflectances

Below are the reflectances from different colored objects.

Figure 5: Reflectance spectrum of a blue colored notebook

Figure 6: Reflectance spectrum of a blue colored notebook with checkered patterns

Figure 7: Reflectance spectrum of a green colored notebook

Figure 8: Reflectance spectrum of an orange colored umbrella

Figure 9: Reflectance spectrum of the cast of the orange colored umbrella

Figure 10: Reflectance spectrum of peach colored notebook

Figure 11: Reflectance spectrum of pink colored notebook

Figure 12: Reflectance spectrum of yellow colored notebook