Physical Science 32

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Sound and Light II

Light and sound can be reflected and refracted, just like water waves. Light and sound can also be diffracted, just like water waves, but diffraction in light is less obvious than in sound. Light and sound both travel in waves, but not of the same type. Visible light is part of the electromagnetic spectrum, and can therefore travel through a vacuum. Sound propagates as a longitudinal wave, and needs a medium to travel through – such as air.


Day 1 – Introduction
Day 2 – Virtual Textbook


0:49 Difference between sound waves and light waves

2:51 Physics – Waves – Introduction

5:47 Transverse and Longitudinal Waves


Copper, orange, yellow/amber, and brown lens tints are helpful in low-light conditions because they make an environment appear brighter. They also enhance contrast and depth perception and are great for overcast, hazy and foggy conditions.

Also, these lens tints block blue light. Blue light, with its shorter wavelength, scatters easier than other colors and makes focusing on objects difficult. Removing blue light improves sharpness and depth perception and reduces eye fatigue. These tints do cause some degree of color distortion, though brown/bronze lenses do so considerably less than the others. (Safety Glasses USA).

  • Position A: Public transportation drivers (bus drivers, in particular) should be a requirement to wear low-light condition sunglasses. The safety benefits of these glasses outweighs expense, inconvenience, or personal preference.
  • Position B: Public transportation drivers should be forbidden to wear any type of sunglasses. Sunglasses alter the appearance of natural light.

Instructor Resources

Standard Daily Material
  • Day 1 – Standard material – introduction day
  • Day 2 – Standard material – reading day
  • Day 3 – Standard material – make a presentation
  • Day 4 – Standard material – give a presentation
  • Extra! – Enrichment and remediation options
Other Topic Specific Resources

Special Notes and Notices

Instructor Emphasis:

  • Science & Engineering Practice: Develop and use models.
  • Cross-Cutting Concept: Systems and System Models.