Developing the educational value of visualizations in physics

Many interesting physical phenomena occur at length scales that cannot be accessed with the naked eye. Some, especially those related to atoms and molecules, are too small. Astrophysical scales can be too large. Modern computations leading to computer visualizations enable access across all length scales. These types of calculations require a large amount of computer resources to carry out the basic computations with sufficient detail and elapsed time. One must think how to maximise the learning experience while minimising the student's technical effort. (Not to speak of minimizing the teachers' preparation effort so they can concentrate on pedagogy rather than developing theirs and their students' computer techniques.) If 3D material is simply presented as flat images its impact is curtailed. Thus interactivity, three dimensional images (stereo where possible) and some carefully curated student activity are needed. I will describe material prepared at the Technion that aids comprehension for not-too-great student effort, but at the same time allows for some ``hands-on'' interaction. Two approaches we use are: smoke visualization for electronic density of wavefunctions and fluid flow (3D, stereo) and WebGL for rotatable, zoomable images of lattices amd molecules. The former require substanial running time and RAM memory to provide the raw data. All of the final visualizations are website based and accessible also on cellphones. The former have an analglyphic stereo option, the latter can be used with Oculus viewers.