Dr. Russell Kincaid’s recent lecture in his Fundamentals of Physics course at Wilmington College dealt with optical devices, including telescopes, which work by a combination of two or more lenses arranged in such a way that allows for a magnified image.
It’s one thing to hear the professor’s lecture and yet another for him to illustrate the concept by showing students how they can build their own telescopes using PVC tubes and inexpensive optical lenses.
“Depending on whether the eyepiece lens is a diverging or converging lens will dictate whether the magnified object will be inverted or upright,” said Kincaid, professor of mathematics and physics, noting it turns out that the magnification is the ratio of the focal lengths of the two lenses.
His students designed their telescopes as part of a laboratory assignment. Each student was given particular characteristics such as “magnification of three, inverted image” or “magnification of six, upright image.” The students were then provided with about 30 different lenses from which they could find the right two to meet their telescope’s criteria.
“Once the appropriate lenses were determined, they calculated the appropriate length of the telescope tube to allow the image to be in focus, then cut 1.5-inch diameter PVC tubes to the appropriate lengths,” Kincaid said. “The results were 10 primitive, inexpensive telescopes with object magnifications ranging from two to six times.”
Another even more significant result was his students gaining experiential knowledge of the physics concepts taught through a hands-on learning opportunity.
PHOTO: Dr. Russell Kincaid views Madison Rice displaying her 2.5 magnification telescope as Taylor Mechlin looks on.