Production and Laser Dye Printing Method of Textile Patterns Based on Inca Dark Constellation Data

Abstract: This art piece is a commissioned work under the I_C project and a collaboration between textile arts and astronomical institutions. The I_C project was initiated by Maria Jose Ríos and sponsored by the Atacama Large Millimeter/submillimeter Array (ALMA), located in the Andes Mountains, involving multiple artists in a cross-national cooperation. The project aims to create a perspective that combines modern astronomical technology and cultural astronomy in the context of textile art. It visualizes modern astronomical data in textile designs to recreate the dark constellation culture in Inca culture. The main objectives of this experiment are twofold: firstly, to establish the range and coordinates of the fictional ancient Inca dark constellations in contemporary astronomical databases, creating a clear contemporary astronomical definition for ancient astronomical cultures that lack specific definitions. Secondly, to design a data visualization method for the dark constellation data, transforming the data into artistic images and using a DIY laser machine and cyanotype printing to print the results of the astronomical data visualization onto natural fibers through optical exposure.

Keywords: cultural astronomy, data visualization, Inca culture, dark constellations, textile art.

1. Dark Constellations and Gaia Database
The knowledge on Inca dark constellations used in this study mainly comes from the research of Gary Urton. The Milky Way in the sky has served human civilization in various forms in various cultures with a long history, whether in navigation, agriculture, architecture, etc. Our interpretation of the universe is largely dependent on our cultural understanding. For example, the cosmology in South America can be roughly divided into the Desana and Barsana systems in the Amazon basin. Quechua civilization, also known as the Inca Empire “Tawantinsuyu”, which is located in South America, share the similar cosmological view. In Quechua, the Milky Way is called Mayu. The relationship between their civilization and the universe can be seen from a street system called “ceque”, in which the main route runs from the capital Cusco to the former capital Tiahuanaco. This road roughly corresponds to the Vilcanota River basin and is consistent with the northwest-southeast axis of the Milky Way.

This led to a cosmology in which the Milky Way in the sky and the rivers on the earth are interconnected. Mayu and the water on earth form a coherent circulation system, with rainwater being carried up to the sky by Mayu and then returning to the earth as river water. “Pachatira” is a term that combines Spanish and Quechua, meaning fertile earth or land. The term probably comes from the earth goddess Pachamama worshiped by the Andean people. This also inspired Gary Urton to discover clues about the culture of dark constellations: the Inca people believed that Pachatira was brought up to the sky by the flow of Mayu's water, forming the images of animals in the sky. In Inca astronomy, there are two types of constellations: (a) star constellations or bright stars composed of a single bright star that make up the "constellation," very similar to Greek and Roman constellations. (b) Dark (or black) constellations are condensates of interstellar gas and dust that appear as dark spots or outlines in bright galaxies and diffuse galaxies. It is likely that the Inca culture is the only culture in which both types of constellations appear simultaneously in the sky.

Figure 1: (Left) Gary Urton at Stellar Connections conference, presenting the  ceque system from Cusco to Tiwanaku, parallel to the northwest-to-southeast axis of the Milky Way galaxy. (Right) Cosmology of the Desana, Basana, and Inca civilizations.

2. 2. Establishment of linking method between ancient constellation culture and modern astronomy database

2.1 Defining the ranges of Inca dark constellations on the Gaia database
In this study, we manually drew the vector ranges of seven dark constellations on the Gaia Archive Visualization and exhibited artwork made from data taken from the Tinamou (Yutu) dark constellation at the Taipei Node94 exhibition. In Inca dark constellations, the darkest and most representative constellation is the bird symbolizing the Andean Tinamou or Lluthu, also known as Chaqwa, P'isaqa, Yuktuq, Yutu, and others in other regions. Lluthu is located in the area occupied by the Southern Cross, to the left of the crucifix star in the Southern Cross constellation, and is part of the current Coalsack Nebula.

The Gaia Project aims to create a three-dimensional map of our Milky Way galaxy, revealing its composition, formation, and evolution process. It accurately maps about one billion stars, equivalent to 1% of the total number of stars in the Milky Way. Since dark constellations are range blocks, they cannot be defined as regional data in modern astronomical databases like traditional Greek systems that link bright celestial bodies to form constellations. Finally, the polygon region was manually created in the Gaia Archive Visualization to define the ranges of seven Inca dark constellations in the Galactic coordinates module, according to Gary Urton's research.

2.2 Using ADQL script as digital substitute for abstract ancient constellations Astronomical Data Query Language (ADQL) is an XML-based astronomical data query language. After using the polygon tool to draw the region of the Yutu constellation on the Gaia Archive Visualization, a string of ADQL code can be obtained. In this exhibition, this query language can be seen as a creative way to use modern astronomical data to reconstruct and digitize the definition of the Inca dark constellations. By entering this ADQL script under the Search tab on the Gaia Archive page, all star data within the region of the Yutu constellation can be extracted. For example, the ADQL script to extract all star data in the Yutu dark constellation is as follows:

Another example of ADQL is to extract star data within the seven dark constellation regions, but only extract specific data such as source_id, ra, dec, bp_rp, bp_g, g_rp, and filter out stars that have been observed multiple times:

3. Laser Dye Artworks and Their Methods Based on Dark Constellation Data

3.1 Audiovisual artwork
This audiovisual artwork presents a subjective imagination of the interferometry principle of the ALMA radio telescope. The data extracted from the Gaia mission was transformed into images and sounds through Max/MSP. The visual design was mainly composed of fractal effects created in Jitter in Max based on the existing patch "fractal.explorer.maxpat". The sound was generated by the 2d.wave~ object, and the star data was linked to the x /y table position of the 2d.wave~ object. A pre-recorded drum sample in length of 10 seconds was already loaded in the 2d.wave~. The original star data and the final data visualization images do not have a direct structural correlation. In other words, the final generated image cannot reflect the characteristics of the original data directly. However, every time the same data is input into the max patch, the same audiovisual result will be produced. These materials can therefore be regarded symbolically as the audiovisual identity of the planet.

In terms of data content, the data of each dark constellation is composed of parameters such as bp_rp, bp_g, g_rp, phot_g_mean_flux, phot_bp_mean_flux, and phot_rp_mean_flux. These parameters are related to the concept of false color, and it is expected that the use of these data will generate abstract conceptual associations with the observation of black holes in the ALMA Observatory in the future. False color is a technique used to display images of different bands or energy ranges. Usually, red, green, blue and other colors are used to represent different bands instead of true colors, so it is called false color. This technique can be used to display thermal radiation, medical images, etc. In astronomy, false color technology can be used to enhance the contrast and resolution of images, thereby better observing the structure and characteristics of celestial bodies. For example, using false color technology, astronomers can observe thermal radiation, high-energy radiation, etc. around black holes, and use different colors to represent different bands, thereby better understanding the distribution of matter and radiation around black holes. In addition, false color technology can also be used to display different gravitational wave frequencies and energy information, thereby better understanding the nature and behavior of black holes. However, at this stage, there’s no direct structural relations between the final images and false color data.

3.2 Laser Dye and visualization of astronomical data
After the astronomical data is transformed into fractal patterns, Laser Dye technology is used to permanently create the patterns onto natural fibers. The Laser Dye Project was developed by Shih Wei Chieh and uses a 405nm near-ultraviolet laser module as the development and exposure light source to expose and scan cotton, linen, silk and other fabrics that have been pre-coated with a New Cyanotype photosensitive liquid invented by Michael Ware. After washing away the photosensitive liquid that has not been catalyzed by the 405nm laser source, a permanent blue pattern is left on the fabric. Unlike screen printing or traditional photographic development processes, which require the preparation of a negative film and can only be done on flat surfaces, the advantages of laser dyeing technology are that it can be used for printing and dyeing on uneven natural fabrics or on the surfaces of three-dimensional clothing. In this study, four pre-printed 105 x 105 cm works were made, each printed with the pattern of four stars located in the Yutu constellation. Another 300 x 300 cm work was created in real-time on-site, depicting the outline of the Yutu constellation on the Gaia database. Due to the use of a darkroom lamp for the exhibition lighting, the finished product has not been fully overexposed within 72 hours and the image outline can still be recognized. The DIY laser machine mainly consists of a set of scanning mirrors and a 405nm laser light source that can be manually focused. Due to the limited optimal distance for the laser light source scanning imaging, the imaging resolution of the 105 x 105 cm work is much higher than that of the 300 x 300 cm on-site installation.

4. References

1. Gary Urton. 2012. Stellar Connections: Explorations in Cultural Astronomy - Pt. 1, Gary Urton. https://www.youtube.com/watch?v=uPhMN5b8tSM
   
2. Giulio Magli. 2005. On the Astronomical Content of the Sacred Landscape of Cusco in Inka Times. Dipartimento di Matematica del Politecnico di Milano.
   
3. Satoki Matrushita. 2017. Basic of Interferometry. SlidePlayer.