In Light and Electricity Studio, students are exploring optics through experimentation and projects.
Take a page with small text printed on it, say a newspaper or a novel. Close one eye and bring it close enough to the open eye so that a small region of text is blurry beyond recognition. Keeping the eye-text distance fixed, pinch your forefinger and thumb together on both hands, and then bring your fingers together to form a pinhole. Look at the text through this pinhole. Can you now see the text in focus?
This has been a driving question this block as the Light and Electricity Studio classes delve into unusual everyday optical phenomena. Students have drawn ray diagrams and studied the behavior of converging lenses. In the process, they have learned about the basic operations of the analog camera that is our eyes, which in turn will serve as our introduction to biological systems. They have embarked upon their journey of studying lenses by making conclusions about their own eyeglasses, questioning what negative diopters mean, and figuring out how they can measure the focal length of a particular student’s glasses.
Mini-projects are one way that we explore concepts in this class; groups work on different projects that are sometimes driven by student suggestions. A group of students worked on whiteboards to explore an aspect of the camera called the depth of field, which was directly related to the driving question about focusing the text. The students drew out their ideas for near and far objects, discussing what was an acceptable amount of blurring for an object. They were able to unravel the geometric reasons behind their observations, as the aperture of their eye lens was "stopped down” by reducing the amount of light transmitted by the pinhole they formed with their fingers.
Another group of students opted to work on a mathematical problem relating the focus to the center of curvature of spherical mirrors, figuring out that the relation was only approximately true, and exploring the conditions under which that is so.
Yet another group has spent time on a construction project to make a device to superimpose two faces by controlling the amount of light through a two-way mirror. They have been working in teams, dividing the work between them into electrical and mechanical divisions. While the electrical team soldered, designed, and rigged up a light dimming setup, the mechanical team has been building a box, blackening the inside, and placing the two-way mirror at precisely 45 degrees. We are all eagerly awaiting the final touches to the project this week, after which it will be decided which faculty member and which student will be the first to test the project!
-- Kaushik Basu