May 16, 2024
Hear from Mark Chantell, Director of Instructional Laboratories:
This is a composite of four separate images of a crystal grown from a super saturated solution of the amino acids Beta-Alanine and L-glutamine, viewed in cross polarized light, and with a magnification of about 100x.
The colors are true in that they are what you would see if you looked through the microscope with your eye. The colors captured by the camera are the result of the cross polarization technique which is used to illuminate the crystals, they are not the result of manipulation done in post processing. In this technique a pair of linear polarizers and a full wave plate are used to manipulate the polarization state of light passing through a birefringent crystal. Which colors make it through this system are determined by the orientations of the polarizers and waveplate, and the orientation and thickness of the crystal structure. Rotating the polarizers and wave plate with respect to one another result in the different color combinations. The flowing shapes which you see are the result of the pattern of growth within the crystal. The only thing which changed from one photograph to the next was the angle of one of the polarizers.
I created these images as part of my research efforts to develop new experiments for the instructional labs that are an integral part of many of undergraduate physics courses. The goal of my research is to come up with images and experiments that not only teach experimental physics, but which also convey the idea that the phenomena we study as scientists has an inherent beauty that goes beyond rigorous mathematical descriptions
