Using the Immersive Theater (the Planetarium) to Understand Stereographic Projection and Develop Visual Penetration Ability in Geosciences

Gary Solar, Buffalo State University
Kevin Williams, Buffalo State University

Abstract

Visual penetration ability (VPA) is critical to envisage 3D spatial relationships from 2D information. Undergraduate geology students do not develop VPA beforehand, yet 3D visualization must be taught to facilitate understanding our science. Teaching 3D in 2D has mixed success using standard study techniques of structural geology including study of outcrop and rock surfaces, analyses of images, mapping, microscopy, and orthographic and stereographic projection. Many of these techniques used to visualize 3D geology are a challenge for the 3D novice, but stereographic projection seems to stump students the most. Few grasp it straight away, and not all understand it even eventually. Some find success by following the steps to produce correct results, but there is only minimal (or no) recognition of why the projection works, and, more importantly, what is being depicted using this tool. A deeper understanding of the 3D relationships is not necessarily achieved, and errors may be common. The challenge is to rectify this 2D-3D learning gap for all students, and geology professors have done their best incorporating technology as it develops.

We have combined established and new technologic capabilities in teaching the stereonet using our planetarium at SUNY Buffalo State University. Like many colleges and universities, Buffalo State has a state-of-the-art planetarium with a perfect hemispherical dome. As digital planetarium systems have advanced, programming has expanded beyond astronomy to other disciplines including the geosciences, often focusing on visualization of global datasets. With modern planetarium capabilities, we postulated we can improve VPA by projecting the stereonet onto the interior of the dome and use lasers and haze to enhance student understanding of stereographic projection in an immersive way. Doing this, students can simultaneously see planes and lines in space, how they are projected through the center of the dome, and how they intersect the dome. It worked! We use the same equal-angle projection the students use, and continue to use afterward. They see that the stereonet is not distorted once projected back into 3D (curved lines are straight, etc.). We re-teach the stereonet, and work through the techniques and problems with the students interactively with hand-held lasers.

This work presents three years of students in Structural Geology visualizing the stereonet in this immersive way. Our results show student cognition is increased relative to before we started projecting the stereonet in the planetarium. We intend to expand our efforts into mineral symmetry, then to spherical plate motion.

Session

Structural geology techniques