Non-visible light, infrared & ultraviolet, were discovered in 1800 & 1801, using spectroscopy. This notion of making a non-visible, biologically inaccessible phenomenon tangible carried into other physical realms, such as study of the sun’s spectrum. With the technological advances of solar spectroscopy, human observations of on-site instruments were translated with lab-based analysis, opening a new technical realm to human witness of the sun.
On August 18th, 1868, a total solar eclipse was observed in Guntur, India - now present day Thailand. The inner, brightest region of the sun was obscured by the moon, creating an opportunity to observe the previously hypothesized solar corona. The British Royal Astronomical Society made an expedition to record this cosmic event via visual, spectroscopic, polarization and photographic observations. 6 photographs were taken at various times of the eclipse, yet the most valuable visual data was drawn by the hand of J.F. Tennant, the expedition lead, while looking through a spectrometer’s telescope. Tennant’s drawing superimposed spectroscopic & photographic data, its analysis confirming the solar corona as the reflective atmosphere of the sun, and even further revealing composition of gaseous solar prominences from detected emission lines associated with hydrogen, magnesium and helium.
Here, analog, human translation of spectroscopic witness unmasks the evasive nature of non-visible light and solar emissions, previously inaccessible phenomena. This record represents the beginning of a shift in technological mediation as data translation thus moved away from the analog, increasing human reliance on computational interpretation to engage with the unseen, in this case, cosmic emissions of non-visible light.
Interstellar interest in non-visible light as a research tool, specifically the ultraviolet range of 10-350nm, drove forward, seeking tangibility of abstract cosmic knowledge. The International Ultraviolet Explorer, a US/UK/EU collaborative space mission launched in 1978, was one of the first missions with a UV telescope on board, for the purpose of mapping the unseen – scanning the sky spectroscopically to identify any sources of this light range. The instruments spectroscopically measured emission energies of celestial bodies, spreading ultraviolet radiation into a greater spectrum of sources. These spectra led to investigation of extreme ultraviolet light, 10-121nm, evident through NASA’s 1992 Extreme Ultraviolet Explorer mission, using 4 EUV-specific telescopes to further scan the universe for EUV sources and build a conceptual understanding of interstellar radiation. These instruments provided computational data that was then computationally translated into a graph representation, representing a method of ‘reading’ the cosmos.
The EUV spectroscopy developed and used for sky scanning on a cosmic macro scale then shifted interest, zooming into the sun, going beyond its visual manifestation to explore its elusive, sensorially inaccessible EUV emissions. Beginning in 1994, this technological paradigm further evolves through interstellar missions and extreme ultraviolet imaging instruments that harness the unseen-- such as the Solar Ultraviolet Imager’s daily images of the sun & solar corona from NASA’s Geostationary-Operational-Environmental-Satellite-19 spacecraft. In this process, the observational paradigm has shifted, the instrumental output no longer tangibly mediated by humans (such as the case of JF Tennant’s hand drawing of spectroscopic data) the output is rather made tangible through further technology -- such as the EUV imager building direct readable images of unreadable phenomena through mechanical sensitivity beyond human capability. The use of EUV imager as opposed to spectrometer, allows the user not only to receive a data translation of a non-visible phenomenon but also a true visualization; harnessing the phenomenon of EUV to ‘write’ what the spectrometer has ‘read’ from the skies.
Parallel in 1994, ASML launched industrialization of EUV technology on Earth, harnessing this unseen phenomenon of extreme ultraviolet light for a separate motive– controlled application and production for photolithography in the semiconductor industry. Originally driven by a US consortium funded by the US Department of Energy in 1999, the investment focus drove ASML progress towards an industrial edge, leading to the development of a unique EUV generation method. This EUV generation method uses tin plasma emissions, rooted in the generational concept of EUV in the solar corona, yet this method of harnessing the unseen quickly becomes detached from the realm of astrophysics and the sun as a natural source of EUV. This recreation of a biologically inaccessible phenomenon aims to make EUV graspable and intricately manipulatable, confining its utility for lithographic progress in correspondence with Moore’s Law, the predictive model asserting that the density of transistors on an integrated circuit doubles approximately every two year, rather than expanding scientific understanding of the phenomenon’s broader physical implications, on both cosmic and microscopic scales.
No individual possesses a comprehensive understanding of ASML’s entire photolithography system operation. Instead, these machines are developed through a distributed model of expertise, wherein specialised teams optimise discrete subsystems without a holistic grasp of their total integration. This results in an emergent technological structure whose functional capacity exceeds any single expert’s cognitive reach, reinforcing the industry’s prioritisation of operational efficiency over intrinsic scientific comprehension.
Therefore, progress in the eyes of ASML is represented by control, and consequent profit over whole understanding. Does the economic structure of technological progress, wherein scientific discovery is subordinated to market-driven utility, preclude interdisciplinary applications such as potential overlap between astrophysical and microscopic semiconductor realms? EUV light, once beyond human reach, has been rendered instrumentally viable, yet its fundamental nature remains secondary to its lithographic function. In the pursuit of industrial optimization, the epistemic value of understanding may be systematically eclipsed by the imperatives of commodification and control.
EUV lithography represents a fundamental shift in the traditional evolution of language, in which inscription supersedes interpretation - reading becomes a secondary function only to support the speed of innovation.
As discussed in our conversation with Fillipo Belletti, a customer service application engineer at ASML, the understanding of EUV imaging relies on the collegial interplay between the human expertise in identifying problems, and computational capacities of the reading technology - one cannot work without the other. This potentially reflects a broader shift in technological production, reducing the role of human capabilities in favour of efficient technological execution, rendering the epistemic need to understand the phenomenon as a whole, useless.
Chip reading microscopy potential futures in computationally intensive methods such as ptychography imaging, currently being developed in collaboration with ARCNL, produces algorithm-driven representations from data reconstructed from scattering patterns. This potential progression abstracts the imaging process from direct observation, placing increased importance on the quality and reliance on the computational model, and further distancing us from direct interaction with our material world.