AAPT.org - American Association of Physics Teachers

2009 High School Physics Photo Contest

Winner's Showcase



Zoom Zoom

Honorable Mention - Natural

Title: Diffraction of Light
Student: Cindy Cin Yee Law
School: Holy Trinity School, Richmond Hill, Ontario
Teacher: Nina Dolgovykh

This picture, taken in the hallway of a house, shows the interference of light diffracted through a narrow opening between two doors. Sunlight streams in from a large bathroom window behind the double doors on the right. One door is slightly pushed back so that there is a 1cm space between it and the other door. When the light travels through this opening, it diffracts and spreads out. At the same time, interference between the emerging waves occurs, causing alternate bands of light and dark. This pattern of dark and light fringes can be seen on the carpet and opposite bedroom doors as shown in the photograph. The interference pattern is so clear that subdivisions of additional bands of light and dark within each bright fringe are also visible. This happens because the source of light is very bright and the projecting screen is far enough from the door slit.

Back Photo Contest Home Next