The Mirror and the Lake

I.
One of the crucial phases of the James Webb Space Telescope’s deployment en route to the Lagrange 2 point was to spread widely the port and starboard wing of its main mirror, followed by fine-tuning the alignments between individual hexagonal mirrors, so that the device could peek into the deep universe with unprecedented clarity and precision. The telescope itself marks the peak of a long evolution of instruments for space observation based on optics. It starts with augmenting human sight by refractor telescopes, using lenses to magnify the observed objects – a technology known to Muslim astronomers from the tenth century onwards, thanks to the pioneering work of Ibn al-Haytham. These designs were later responsible for Galileo’s discovery of Jupiter’s moons and the rings of Saturn, but in the early modern era, they quickly hit the ceiling of their capacities as the ambitions of scientists to look further grew. Hence a generation of scholars including Isaac Newton brought about the concept of a telescope which would use mirrors to reflect light, instead of bending it by lenses. Since then, reflecting telescopes have become the main tools for deep space observation, and their principle has also been adopted for detectors of light in different wavelengths beyond the visible spectrum – such as radio telescopes with their signature saucer design, and infrared telescopes such as the James Webb.

II.
Light is an electromagnetic radiation, a stream of photons. Astronomy was initially based on observing the sources of these particles. However, since roughly 1950, we have learned that cosmic objects beam in the direction of our planet streams of various particles, including such peculiar ones as neutrinos. Thanks to their properties, neutrinos regularly occupy the charts of the weirdest particles in physics – they interact only through gravity and weak force, and hence while other particles tend to get ‘blocked’ by the matter they are beamed at, neutrinos easily pass through as ghosts. Despite their relative abundance in the universe, this ghost-like quality makes them hard to detect, and hence instruments that try to glance neutrinos must be extremely large in order to raise the probability of a neutrino interacting with the detector’s mass. Such neutrino telescopes currently operate in several parts of the world – they are immersed in Antarctic ice sheet (IceCube Neutrino Observatory), under the Apennine Mountains in Italy (Borexino experiment), and in the waters of Lake Baikal (Baikal Gigaton Volume Detector). It is the last one that becomes the focal point of this story – but before talking more about it, there is a philosophical detour to be made.

III.
As it happens, optics was one of the favourite disciplines of early modern Western philosophers. Renée Descartes and Thomas Hobbes wrote significant volumes on the bending and reflecting of light. Baruch Spinoza was a lens-grinder. And another philosopher – Gottfried Wilhelm Leibniz – placed optical metaphors at the centre of his metaphysics. In his account, the universe is composed of manifold simple substances, called monads, which have no extension, nor intrinsic structure, and which cannot be divided into smaller parts (to list just some of their peculiar properties). As Leibniz puts it, ‘monads are the true atoms of nature and, in a word, the elements of things.’ The optical metaphors come in the moment when Leibniz aims to explain how to imagine their interaction: each monad is a perpetual living mirror of the universe, as if it had an original standpoint, or perspective, from which it apprehends the world. This relation of ‘mirroring’ is an extremely potent philosophical metaphor to play with. Apart from its usefulness in understanding distributed computational networks, it can describe ecological adaptations of organisms (such as mirroring the features of the environment in the body composition) or the purposefulness of designed artifacts (in mirroring either organs that operate them or the objects they are aimed to handle).

IV.
To say that things in the world mirror each other means to imbue them with elementary mediality – they bend, reflect, absorb, and hence facilitate flows of actions, images, and information. Were we to look at the universe with these eyes, what insight would we get about general concepts such as the cosmic, the planetary, and the living? Would we also discover some mirror interplay between them? This is where the Baikal Neutrino Telescope comes back into the picture. The device has been under construction since 2016, aiming to cover 1 km3 of water mass with optical sensors in the form of glass hemispheres hiding photomultipliers that produce electricity in response to light. One of its main purposes is to catch neutrinos that travel in the direction of Earth from distant galactic nuclei. There reside ‘natural particle accelerators’ – supermassive black holes that send streams of high-energy particles across the universe in relativistic jets. These streams are seldom detected, since most of the particles interact with Earth’s atmosphere and crust, but as we know, neutrinos are the exception, raising a detection probability of such streams by discovering neutrinos interacting with the telescope in the form of Cherenkov radiation. In a way, the scientific value of such an experimental device is no different from those at CERN – it just cunningly uses cosmic affordances, thus disposing of the need to produce particles in an accelerator.

V.
With respect to the first picture of a Black Hole taken by the Event Horizon project in 2019, Ben Bratton has noted that it is ‘crucially not a picture of our Earth, but rather a picture taken by the Earth of its surroundings – for which we served as essential enablers.’ A double inscription of elementary mediality occurs here. First, on the level of humans, they are told to be mediators-enablers of the picture purchasing process: folding the minerals formed during the geological past of the planet into sensory devices that make the image possible. This idea of humanity’s medial role resembles Nietzsche’s thinking about humans as somehow interestingly uninteresting – ‘the most unfortunate, most delicate, and most transitory beings’ – thus giving humanity some taste of exceptionality, even if in negative terms. That changes, however, with the second layer of mediality emerging from Bratton’s claim: the planet folding cosmic matter to generate life, with humans as one of the byproducts of this evolutionary process. Such reading pushes further the decentring story of the human’s medial role, leaving the species-level behind and focusing instead on understanding the planet as a meeting point of extra- and intra-terrestrial processes. In such a perspective, the cognitive achievements of humanity are rather results of mobilisation of whole ecologies and ensembles of matter engaged in mirror games, not singular breakthroughs of smart brains.

VI.
The Baikal Gigaton Volume Detector is more than a planet folded into hardware, made by a planet folded into wetware – it is an augmented ecology that activates the planet’s ‘innate’ mirroring capacity. Mobilizing this capacity means engaging in another kind of mirroring business, one that is not organized around apprehending the universe by homo sapiens, but around channelling cosmic metabolisms of images. Remember Leibniz’s monads – the perspectival mirrors of the universe. If life is a modality of perspectival contraction of cosmic matter, mirroring the extra-terrestrial in its uncountable terrestrial manifestations, the Baikal Neutrino Telescope is but another modality of such a contraction – not necessarily an organic one, but surely activating affordances hidden in the alignment between the lake’s ecology and the otherworldly ecology of black holes. After all, to place such a device at Lake Baikal is no coincidence – its pure water functions as a filtering membrane that minimizes possible noise and allows only almost massless particles such as neutrinos to pass to the detector. Yet this game of cosmic mirroring does not end in the deep waters of the lake. Neutrinos play their own mirror game that may even lead to an explanation of the prevalence of matter over anti-matter in the universe: they violate parity, meaning that their mirror particles, called anti-neutrinos, do not have properties symmetrical to their counterparts (in particular, they change flavours at a different rate). Hence, beyond the immediate scientific use of the instrument, the Baikal telescope also introduces deeper cultural and philosophical implications – it is a tool of attuning to the mirror games that deeply link ecology to cosmology.

This essay is based on a conversation between Lukáš Likavčan and Dmitry Naumov, head of the JINR Neutrino Programme at the Baikal Deep Underwater Neutrino Telescope.