This tries to establish a terminology how digital aspects are attached to virtual ones in the [[Metaverse]], based on a concept called the Triangle of Reference (also known as Semiotic Triangle). While we won't discuss its meaning and significance in semiotics, this model can help understand how digital dimensions correlate to the physical and mental ones. The triangle of reference tries to illustrate that a symbol (for example a word in a language) can't refer to a thing (the object the word stands for) directly. Instead the reference is made by utilizing an abstraction of the thing in the mind of the writer or the reader of the symbol. ![[Triangle of Reference The Meaning of Meaning.png]] *Figure taken from page 11, The Meaning of Meaning: A Study of the Influence of Language upon Thought and of the Science of Symbolism, 1923, was co-authored by C. K. Ogden and I. A. Richards, Magdalene College, University of Cambridge* Simplified, the triangle corners mean the following. • The physical world is made out of objects, situations and events that make up our reality. In the triangle those are referents, signifying one specific "thing that exists", be it an object, situation or event. • In our minds, the thing becomes a mental model, which is based on our experience with this specific thing or other like it. This is a reference or "what we understand the thing to be". • If we talk about this specific thing or things like it, we are using words, images or other forms of abstraction as the symbol that represents "how we call the thing". As an example: * **Referent**: This specific light bulb, hanging in front of the person * **Reference**: The light bulb how the person imagines all light bulbs to be * **Symbol**: The symbols that the person uses to refer to a light bulb (for example "💡" ) The lines represent the model in action: * The symbol stands for the referent - "💡" stands for the specific light bulb * The symbol symbolizes the reference - "💡" stands for the mental model of all light bulbs * The reference refers to the referent - The mental model refers to this specific light bulb ## References in physical and digital space When we construct our individual physical reference, it is mostly based on our previous experiences with similar objects. If you see a light bulb or indeed any other object, you will have a good idea about its properties, like weight, texture, temperature or smell. Additionally, you will have a good idea about its capabilities and uses, for example "can bring light to dark environments". Variations of properties or capabilities can create further distinctions within the reference, for example "overhead lamp", "desk lamp" or "flashlight". Note that this reference is subjective, since everybody has had different experiences and interactions with things. This is especially true for abilities. For most people a light bulb will still be one color, emitting some form of neutral white light. However some light bulbs might have properties or abilities that go beyond this expectation: LED lights usually run less hot than traditional bulbs with a glow wire. Some lights are dimmable or can change color. They might be heavier due to additional hardware. After experiencing additional behaviors, people will extend their reference model to include them. The digital reference lists the all potential properties and abilities of the physical thing. As a reminder, a "thing" can be an object, situation or event, even a person. Depending on what it is, it will use a different type of digital reference and concept. If the thing is a physical object or person, the digital representation will be based on [[Digital Twins]]. If the thing is a concept, like a situation or event, the digital representation will be based on a [[Computational Graphs]]. The digital reference serves the same purpose in both concepts: To define a model of the object within the system. In technical terms the digital reference defines a data structure, which describes the object itself (as metadata) as well as its specific properties and abilities. As much as physical references are subjective, digital references will also differ from object to object and system to system. Individual manufacturers will use have different structures for their APIs, as will providers of digital twin and graph platforms. As a result there are many references for similar objects, depending on manufacturer and the system / platform that is used to manage them. The following screenshot shows the structure as defined by Philips for their hue Lights API. ![[Philips Hue Light API.png]] *Philips hue, Lights API, [Philips Hue Lights API](https://developers.meethue.com/develop/hue-api/lights-api/)* The Philips hue API does also contain aspects to request information about the capabilities as well as metadata like manufacturer, model and even software version. For comparison, the API for LIFX light bulbs looks similar, but is structured differently. ![[LIFX Lights API.png]] *LIFX, Lights API, [List Lights · LIFX HTTP Remote Control API](https://api.developer.lifx.com/docs/list-lights)* Ultimately, all APIs for smart objects or graphs act as standardized references how to describe things, including what they are, their properties and abilities. They can also be extended over time by publishing new versions as new capabilities are developed. Then there is [Microsoft IoT Plug & Play](https://docs.microsoft.com/en-us/azure/iot-pnp/overview-iot-plug-and-play) - a descriptive language to create a device model that a device uses to advertise its capabilities to an IoT Plug and Play-enabled application or system. As well as [Digital Twin Definition Language (DTDL)](https://github.com/Azure/opendigitaltwins-dtdl/tree/master/DTDL) - a descriptive language how digital twins and their relationships are defined. ## Referents in physical and digital space The physical thing will have properties and abilities it exhibits in the real world - it exists and can be sensed or measured: The visible light emitted by the light bulb, the heat it radiates, the smell of warm air around it, the taste of metal or plastic, maybe a faint hum. It also exists at a specific time and place. ![[Philips Hue with Bluetooth.png]] *Philips Hue with Bluetooth, Signify, [Set the perfect look and feel in your room with new Philips Hue with Bluetooth | Signify Company Website](https://www.signify.com/global/our-company/news/press-releases/2019/20190627-signify-launches-philips-hue-with-bluetooth)* The digital referent is a measurement of the physical state at a given time, accessible in digital form. This includes all the information defined in the reference that a thing will expose digitally. Looking at the API specifications earlier, the referent is the actual data provided by the thing for a specific point in time - the current brightness, hue, saturation, its temperature and so on. Everything that can be sensed digitally about the thing itself and sent via the API becomes referent data. As it is only data, the digital referent can't be interacted with. Opposed to a physical object the digital representation has no form to touch or otherwise manipulate. Digital referent data is usually changed via some form of digital interface, for example a smartphone application or a UI living in mixed reality. The main difference to a physical object is that there can be many interfaces that manipulate and indeed represent the same digital referent. So there is a need for a new concept in digital space where the digital referent represents the data and it can have a number of augmented referents representing its form. ## Summary The extend the model with digital dimensions looks like this: • The **physical reference** is the representation what a person understands a thing to be • The **physical referent** is the actual thing, in our example the one specific light bulb • The **digital reference** is the standardized data template of what the thing is understood to be • The **digital referent** is the actual data that represents the current state of the thing. • The **augmented referent** is how the thing is digitally represented to the person in physical space • The **symbol** is the same for both dimensions ![[Physical and Digital Space Reference and Referent.png]] *Images by Philips Hue / Signify, [Hue White and Colour Ambiance Iris table lamp | Philips Hue (philips-hue.com)](https://www.philips-hue.com/en-gb/p/hue-white-and-colour-ambiance-iris-table-lamp/8719514264489)* In terms of digital concepts as defined previously: • The digital reference is implemented through a data structure and API specifications • The digital referent is represented as a digital twin or computational graph • The augmented referent is the user interface on a digital device