A 7.2 megapixels, Sony Cyber-shot camera was used to capture the interference pattern. Two electrical toothbrushes were used to create waves in the water. Both of the brushes in this photo had the same speed and thus the same frequency. This photograph shows how waves produced from two sources interact to produce wave patterns. Interaction of waves results in superposition of waves. According to this principle, when a crest meets another crest it creates a supercrest and when a trough meets another trough it creates a supertrough. This is known as constructive interference and produces a resultant wave of greater amplitude. Interaction between a crest and trough produces a node, resulting in a wave of lower amplitude which is known as destructive interference. The reflection of the toothbrushes can also be seen along with the wave patterns in this photo.

---

Brahmdeep Saini
Emery Collegiate Institute, North York, ON
Third Prize ( High School Class Category )

---