Astronomy in Paper - Quilling to Engage with Beauty and Communicate Science

Introduction

Paper quilling is the art of rolling and curling thin strips of paper, placing them on edge, and forming them into shapes, mosaics, and designs, and it is hundreds of years old.  Global societies of quillers and dynamic online groups exist for sharing the art, exchanging ideas, and promoting the form.  The highly flexible and malleable nature of paper quilling makes it ideal as a medium to meld science and art.  Quilling can be used for impressionistic or abstract work as easily as it can be used to create realistic, detailed, lifelike pieces.  Paper quilling sculpture can be exceptionally large scale, with some installations covering entire walls, and it can also accommodate the utterly meticulous work of tiny, 3D miniatures.  This abstract offers examples of three science topics one may explore with astronomical quilling, and illustrates how they are brought together using the example of the artwork “Spiral Moon.”  This text is to be of use to artists with limited astronomical knowledge as well as to space scientists.  Additional work is underway, and along with “Spiral Moon” may  be available for exhibition.

The Science Concepts

Albedo - The ‘albedo,’ the level of light/dark in an image, is similar to what an artist might call this ‘value.’  But scientists typically only use ‘albedo’ with black and white images.  The relative and absolute quantities of light and dark are the most basic kind of image data, and yet they can reveal topography, composition, shadows, and all basic land formations.  If the albedo across the image changes slowly, one might infer that the light is being diffused by an atmosphere.  If the albedo across an image changes sharply, that might indicate that there is no atmosphere to scatter the light.  The ability of paper on edge to sharply reflect or softy diffuse light makes it highly useful in illustrating these concepts.   

Point-Spread Function - The ‘point spread function’ or PSF is the response of an imaging system to a point source of light – the PSF may extend or diffuse the object into a blob.  If one understands how a device ‘spreads’ light, then one can apply techniques to help correct.  A common instrument used in astronomical research is a CCD (charge-couple device).  Generally speaking, a CCD is a grid of tiny detectors, each of which records how much light it has detected over a certain time interval (integration.)  Each of the boxes on the grid is a pixel, a tiny square making up the image like a mosaic of tiles.  If an astronomer is interested in taking an image of a point source, like a star, ideally all the light from that source would fall into a single square, but in practice that is not what happens.  Mosaics of paper quills can be used as an excellent analogy to similar pixelated images.

The Opposition Effect  - The Opposition Effect is the enhanced brightening of a surface that is covered with dust, particles, or is naturally rough, when the source of light falling on it is directly behind the person viewing the surface.  The Opposition Effect or Surge refers to the non-linear way that the brightness of the surface increases as the phase angle goes to zero.  The ‘phase angle’ is the angle between the observer, the object they are observing, and the source of the light that is illuminating the object.  That is, as the source of light shines more directly on the object from the observer’s perspective, the phase angle goes from higher to lower numbers.  At 0 degrees, your source of light is behind you, shining directly on the object you are looking at.  The Opposition Surge is a complicated effect – one major factor that might contribute is ‘shadow hiding.’  At higher phase angles, there is more of the surface hidden in shadows.  As the phase angle goes to zero, there are areas of the surface suddenly revealed, reflecting light back to the observer.  At opposition, it can be easier to see differences in composition (more calcium rich areas (light) vs more magnesium rich areas (dark)) but it is hard to see the topography.  Paper quilling offers an excellent medium, as the inherent depth of each quill and their interspacing can mimic this effect.

Bringing it Together – Quilling the Moon

The art piece “Spiral Moon” - by artist JA Grier,  is craftedof more than 2000 individual quills, all loose coils.  In creating this piece I considered a variety of scientific concepts and a range of possible artistic expression.  As a lunar scientist as well as an artist, I wanted a ‘realistic’ representation of the moon that also conveyed wonder and beauty.  I wanted the viewer to see something both expected and unexpected at the same moment.  In terms of albedo, the near side is a fantastic example of the power of the contrast of light and dark, with the dark maria, bright highlands, and extra-bright, young, rayed craters in juxtaposition.  Stark contrasts and subtle shading are used to demarcate familiar features, but in unfamiliar ways.  The few straight pieces of paper stand out in a sea of circles, just as the real rays of the youngest craters do on the Moon.  The art uses only four shades to convey the entire range of light to dark of the lunar surface.  Our eyes and brains have their own PSF, allowing us to look at bits and pieces and integrate them instantly into a coherent picture.  Paper quilling is by its nature a dimensional, sculptural medium.  Coiled paper creates valleys, grooves, shadows, and angles that allow for a strong opposition effect, but perhaps not in the way one might always predict.  Depending on the paper’s color, width, and placement, the effect might be stronger from an angle where the sides of the paper are more visible than the edges.  Spiral Moon uses this phenomenon to enhance the realism, as well as sense of the unexpected.

This work first appeared as a part of the “Making Space” art and science workshop, PI Jamie Molaro.