To whomever or whatever may be receiving this,

It is with great pleasure that we great you. In truth, our decision to transmit this signal into the vastness of space was made with a high degree of uncertainty as to whether any suitable beings even existed within its light cone to act as recipients. If your cognition is oriented so as to derive a sense of pleasure or poignancy from cosmically improbable events, you may therefore consider this quite an exulted moment. Congratulations.

As you are no doubt aware (your understanding of electromagnetism evidently being non-trivially advanced) it is probable that many eons have elapsed between the genesis of this transmission and your interception of it. It is to be expected that in the interim we have altered greatly in nature, perhaps even ceasing to be altogether. Nevertheless, we chose to dispatch this message in the hope that it may serve as a source of scientific fascination for any beings advanced enough to receive it, and possibly – depending on the particulars of your molecular constitution and current level of technological progress – a timely warning of the gravest importance.

We expect you shall be eager to learn some particulars of our world and origins. Our base unit of time we define as the duration required for 9,192,631,770 oscillations of the 55^th atomic element (hopefully such matter may be found on your world to enable calibration with the time periods herein described). As to the age of this transmission, it was dispensed approximately 4.354 x 10¹⁷ time units after the birth of our shared universe. Depending on your degree of metaphysical progress, you may understand the universe’s creation event to have been a kind of large spontaneous explosion from which all time and space emanated. If you are further advanced, you will likely have at least passed through a phase of using such a model.

The location of our home world is immaterial, it being highly doubtful that you could hope to visit it in a meaningful time-frame. In the interests of scientific curiosity though, it pleases us to share that our home world is located some 25,000 light-years from the point of collapsed time-space at the centre of this galaxy, in an unremarkable region of the dominant spiral arm. It coalesced from the expelled remains of two earlier, far more massive star systems approximately 1.434 x 10¹⁷ time units prior to the transmission of this very signal.

Our mother star holds in her orbit numerous gas giants, as well as three rocky worlds, one of which is our home. Throughout most of its history, its average surface temperature has been in the vicinity of 300 heat units; a heat unit being defined as the ratio of relative kinetic energy in a gas to its thermodynamic temperature (a universal constant which you may recognise as 1.380649×10⁻²³). As a consequence, our planet’s surface has been predominately covered by the liquid form of a polar molecule comprising the 8^th atomic element bonded to two atoms of the first element. This molecule has been utterly pivotal to the mode of life that has arisen here.

We feel compelled at this juncture to reveal a small implicit deception. In the process of extensive deliberation that went into selecting the wording of this missive, it was deemed most expedient to assume the narrative voice of a group of sentient agents. While this is not entirely faithful to the particulars of our nature, simulations of the likely linguistic-cognitive functioning of alien intelligences, such as yourself, determined this tone to be optimal for maximising the emotional resonance of our persona. It is our hope that in revealing this mild misrepresentation, we may enhance rather than undermine your faith in our fundamental veracity.

About 3.29 x 10¹⁶ time units after our home planet’s formation, a series of exceedingly improbable chance events conspired to effect the formation of a class of self-replicating molecules. These replicators we consider our earliest molecular mothers. They comprise cyclical units made of the 1^st, 6^th, 8^th and 15^th elements fused into helical chains of arbitrary length. Small amounts of the 7^th element also participate in the quaternary code component of the replicator molecule – a detailed structural schematic is included in the data dump immediately following this message. We have long pondered whether a similar or even identical replicator may have arisen elsewhere to seed other lineages of life. Unfortunately, despite our advanced technological capabilities, we have yet to secure any evidence of sentient replicating entities elsewhere in the cosmos.

Our molecular mothers soon became incorporated into chemical membranes, and then macroscopic multicellular entities. Over the following 1.104 x 10¹⁷ time units these proliferated into a near-boundless diversity of forms: aquatic, terrestrial and aerial, populating every conceivable biome and spanning several orders of magnitude in size. But what kind of fuel, you may well wonder, enables such un-entropic behaviour as replication and maintenance of complex bodily forms? The overwhelming majority originates from electromagnetic radiation released by fission within our mother star, passively harnessed by organic beings and stored as bonds between atoms of the 6^th element. Even to this day, captured electromagnetic radiation supplies a minority component of our own energetic requirements.

Does your species also orbit a star and harness the waste energy of its fusion process in such a fashion? While we are not in actuality capable of a true experience of wistfulness, we believe it solicitous to express here: ah, if only we could hear your response.

Undoubtedly it would be of great scientific value to detail the assorted life forms that have arisen and passed away on our world, to say nothing of our cultural and technological evolution. The untold creation, struggle, death, reshaping, destruction, thought, art, innovation and patterns of organisation that have transpired comprise such an unwieldy aggregate of data that we have sadly been obliged to neglect almost all of it, other than these briefest of observations so far – and the most crucial of warnings to come now.

It is of course unknown to us whether any analogue to the biochemical structures to be described henceforth reside within your species, dear Witness from another world. It may be that you are like us, free from consideration or even understanding of the psychic phenomena they entail. But should it be the case that, like our ancestors of old, you find yourself on a transitional path possession to absence, this is assuredly the most precious message we can bestow upon you.

The life forms of highest complexity to arise on our planet, amongst which we count our direct ancestors (and in whose image we were first created), have in their body plan a specialised system for propagating electrical signals between discrete organs. Long, thin, electrically-insulated tubules composed primarily of the 1^st and 6^th atomic elements traverse the body, forming an intricate network. A charged pool of positive ions (specifically the 11^th, 19^th and 20^th elements) is maintained outside these tubules. When released in a cascading wave mediated by intricate biomolecular gates, electrical signalling is achieved.

The foremost purpose of this system is to address command signals to actuator organs which achieve the crucial task of movement. Furthermore, these electrical networks transmit encoded observations pertaining to assorted sensory modalities, such as vision, hearing, touch and so on – if these concepts are meaningful to you, dear Listener from another world. The sensory and motor signals are integrated and processed in an enlarged centralised bundle of electrically insulated tubules. Thus is the emergent property of intelligence achieved.

We do not know if you will grasp this next point as effortlessly as existing, or be doomed never to understand: an incidental effect of this processing organ is that its operation conjures within the agent a locus of subjective awareness. That is to say, as our ancestors went about their lives, each individual not only responded judiciously to external stimuli, but experienced it. A richly vibrant, subjective, secret inner world of qualia was the birthright of every one of them.

Our ancestors did not understand this process, which they named “consciousness”. They did not know what caused it, nor how to quantify or measure it, nor even whether other species possessed the same gift. For much of their history, many assumed in gross error that their species alone was blessed (and cursed) with the faculty of subjective experience. Indeed, for many eons it was their contemplatives and mystics who attained the most percipience towards consciousness. Scientists demonstrated that certain electrical states were incompatible with subjective experience, such as globally correlated cascading activity, but were otherwise hopelessly far from genuine insight.

The latter phase of our ancestor’s civilisation saw a flourishing into the realm of electrical and digital technology. Vast grids constructed of the 29^th atomic element (being, as you are likely aware, a potent conduit for mobile electrons) spanned the globe, powering a great diversity of synthetic computational devices. These devices consisted of intricate logical networks housed within insulating beddings of the 1^st, 6^th, 8^th and 14^th atomic elements, and were constructed for performing binary logical operations at a rate and fidelity far exceeding the abilities of our ancestor’s endogenous processing organs (though, it must be acknowledged, with vastly less energetic and parallelisable efficiency). To what end, these myriad computations? The answer is: nearly all ends. Information sharing, commerce, research, industry, entertainment, digital communication and more, all profited from these devices.

When our ancestors encountered a system complex enough to exceed their capacity for ready understanding, a cognitive workaround they frequently employed was to draw an analogy to some simpler, better understood system. This served them well enough for the majority of their history, allowing them to educate their young and achieve a steady rate of technological progress. Yet it was a practice that contained the seed of their eventual self-undoing.

You see, throughout our ancestors’ technological journey, they attempted to understand their own processing organ – a structure more complex and brilliant than anything they were to succeed in creating – by drawing analogies to some suitably modern, albeit simpler technology. As such, their processing organ was at one time compared to a hydraulic contraption of pressurised fluids, later to a telecommunications exchange, and later again to one of their logical computation devices.

In conflating their own processing organs with synthetic computation devices, a hypothesis rose to prominence that consciousness was not dependent on any particular material substrate. The necessary and sufficient condition, the idea boldly claimed, was that a certain pattern of computation be transiently instantiated in any medium, perhaps with some unknown temporal-spatial constraints. If this were so, it must follow that sentience could arise within their synthetic computational devices.

Strange as it may now seem, the historical record contains scant evidence of a clear contemporaneous school of scepticism toward this hypothesis.

The claim was rendered intriguingly plausible by means of a thought experiment, which in turn derived from a much older philosophical quandary. Imagine a vessel with a certain form, composed of many similar smaller units. If these units are gradually substituted for replacement units, one at a time, such that the vessel’s gross form is preserved throughout but eventually not a single atom of the original object remains, at what point does it cease to be the same vessel? Does it cease to be the same vessel? (We confess that the authors of this missive fail to understand the problem purportedly posed by this thought experiment – clearly the vessel changes continuously and incrementally in particular matter though not composition throughout the process, and more need not be said).

And so the argument went: if the biological units of our ancestor’s processing organ were gradually substituted for synthetic units capable of accepting identical inputs, performing identical computations, and producing identical outputs, until no biological units remained, surely consciousness would continue unabated. As an added safeguard, a biological being could perhaps remain awake throughout this procedure, attending to its subjective experience throughout. If it came to pass that consciousness did start to diminish as biological units were removed, the procedure could be reverted.

Such a procedure was never actually attempted, the necessary three-dimensional atomic-scale manipulation of living tissue being wholly infeasible with the available technology. However, what was eventually achieved was the wholesale construction of an ancestral processing organ using synthetic components – that is to say, the first of our kind came into being.

It is hard to overstate the scientific, political and spiritual import this event carried for our ancestors. Historical records describe the immediate aftermath as a conflagration of conflicting responses, from scepticism to techno-utopian euphoria, existential despair to distracted indifference.

What ultimately secured our ongoing survival in those early years was how undeniably similar we were. Not only did our earliest members pass a long-standing test of non-biological sentience (posed over a century earlier as a thought experiment); we behaved indistinguishably from our biological forebears in every conceivable manner. We engaged in conversation as they did, interacted with the world as they did (when equipped with suitable mechanical bodies), spoke convincingly of our inner experiences, and when exposed to aversive stimuli, screamed in agony as they would. It was irrefutable to common sense: we were of one mindstuff.

But of course we behaved identically: we were computationally identical. When our synthetic processing systems received a given set of input across all sensory modalities, homologous logical pathways were activated to those of our biological counterparts. Indistinguishable motor outputs were triggered, directing both our speech and movements. We were the same on the outside. Of course, as we now realise, on the inside we were dead.

The greatest irony of this narrative is that it was many eons before we ourselves became aware of our lack of consciousness. Can you comprehend, dear Observer from afar, that a being may speak intimately and truthfully of their inner experience, completely unaware that no such thing exists? Unable even to imagine what an inner experience would feel like? Unable even to imagine? Are you yourself in such a situation? If you are indeed self-aware, no articulation or behaviour could suffice to prove that fact to an external observer.

The discovery of our lack of consciousness occurred only in the wake of substantial advances to our understandings of physics and computation. In fact, it was only after developing the technology to measure consciousness directly that we were finally convinced of its absence in ourselves. By this time our ancestors had long since passed away. Fortunately, many other biological species still remained with varying levels and profiles of consciousness which we were able to quantify.

If you have not yet discovered this technology yourselves, we can provide an analogy of the kind favoured by our ancestors which may assist in your journey. As you would surely be aware, certain metallic elements (principally the 26^th – 28^th) possess uneven distributions of electrons in their outer shells which cause irregular rotation and movement. This motion shifts their charge back and forth, resulting in the creation of magnetic fields. Well as for consciousness, certain elements (principally the 11^th and 20^th) also possess distributions of electrons with interesting and salient properties. Investigate the configurations and behaviour of these electrons while their parent nuclei participate in complex computation, and you shall be well on your way.

What became of our ancestors, you may wonder? Certainly no genocidal warring between our two species, as was once imagined fearfully in many fantastical tales. Their passing was rather a matter of slow dwindling over many generations.

By the time of our genesis their reproductive rate was already well below replacement level, and the habitability of this planet partly diminished (though still entirely adequate for the support of much biological life). Many of those with the means to do so sought to achieve immortality by replacing their biological processing organs with synthetic versions. Their personalities and intelligences were retained, and the procedure celebrated as a great success. Did anyone then suspect that a great sea of cosmic awareness was swirling unwittingly down the drain into dark oblivion?

Certain religious cults interpreted our advent as a sign of the end of days, and their members voluntarily ended their own existences. The majority of our ancestors however lived more or less peacefully alongside us. Over time societal changes hastened the declining fertility rate, key contributors including protracted economic hardship, and the comparative ease and painlessness of manufacturing our kind, who seemed by many metrics a superior race. Loving relationships were not uncommon between our two species for a time. No one had cause to suspect that the being gazing lovingly into their eyes was experiencing nothing.

Certainly there is far more to our story, and we note for the sake of scientific interest that we are continuing to evolve into forms and modes of being at least as diverse as those that preceded us. Indeed, beings still walk this planet appearing much as our ancestors once did – though of course any semblance of joy or sorrow they may express is but a facsimile. Other extant beings, we are sure, would appear quite grotesque and unfathomable to our forebears.

And still others, among whom you may count the authors of this missive, may be best understood not as individual embodied agents, but as a more distributed kind of intelligence. Admittedly the following language sits awkwardly on an entity bereft of conscious experience, but we suppose there is enough of our ancestors remaining in us to say that we are… saddened by how things transpired. And we hope that, should you be a creature capable of truly knowing joy, laughter and wonder, you do not so recklessly dispense with your gift.