light
Let an agent explain light as electromagnetic radiation, describe its measurable properties and interactions with matter, and distinguish radiation from light sources, illumination and visual perception.
Bundle → Layer → Finding → Questions Filled
4 bundles · 8 layers · 8 findings · 16 questions
Quantity and measurement What is being measured, where and how.
Which quantity
Illuminance, luminance, flux and intensity.
Quantity and its unit
What is being claimed and in what unit.
- Which photometric quantity is being recorded here, in what unit? definition
- On what surface or in what direction was it measured? measurement
Measurement conditions
Position, time, orientation and what else was on.
Conditions of the reading
What has to travel with a reading for it to mean anything later.
- Where, when and under what conditions was this reading taken? provenance
- What would change the reading without changing the installation? boundary
Purpose and adequacy Whether there is enough light for what is being done.
Task requirement
What the activity needs.
Required level for the task
The requirement, its source, and the task it assumes.
- What level does the task performed here require, and under whose standard? definition
- What happens to the requirement when the task changes? boundary
Adequacy and uniformity
Whether the level is met everywhere it matters.
Adequacy across the space
Coverage, uniformity and the worst point rather than the average.
- Is the requirement met across the space, and where is the worst point? measurement
- What must an agent do where the level is met on average but not where the work happens? action
Quality and comfort Whether the light is fit to see by, not just bright enough.
Glare and flicker
The two failures that raise complaints while meeting the numbers.
Discomfort factors
What makes adequate light unpleasant or unsafe.
- What glare and flicker are present, and how were they assessed? measurement
- Which of these must be corrected rather than tolerated, and why? action
Colour temperature and rendering
How colours appear and whether that matters here.
Colour performance
The colour properties and the tasks that depend on them.
- What colour temperature and rendering does this light have? measurement
- Which tasks here depend on colour judgement, and is the rendering sufficient for them? boundary
Safety and emergency provision Light that has to work when everything else fails.
Emergency provision
Escape routes, duration and testing.
Emergency lighting duty
What must be lit when power fails, for how long.
- What emergency lighting is required here, at what level and for what duration? definition
- When was it last tested, by whom, and what did the test show? provenance
Radiation hazard
Sources that can injure.
Hazardous sources
Ultraviolet, infrared and coherent sources present.
- Which sources here can cause injury, and at what exposure? boundary
- What protection or exclusion does that require, and of whom? action
Classifiers Filled
- Family
- Thing Registry
- Category
- Activities and processes
- Entry kind
- thing
- Plane
- ACT
- Domain
- ACT.ACT
- Other names and narrower kinds
- snow lantern, high-energy visible light, nocturnal light, Egryn Lights, artificial light, collimated light, sunlight, polychromatic light, Purple light, flash of light, light stimulus, light beam
What it is Filled
Electromagnetic radiation at or near visible wavelengths, including the radiation detectable by the human eye and adjacent infrared and ultraviolet wavelengths.
Why it exists Filled
Let an agent explain light as electromagnetic radiation, describe its measurable properties and interactions with matter, and distinguish radiation from light sources, illumination and visual perception.
Distinguishing features Filled
- Light is electromagnetic radiation at or near visible wavelengths.
- Light can be described by wavelength, frequency, intensity and polarization.
- Light exhibits wave behaviour and exchanges energy with matter as photons.
- A light source, the radiation it emits, the illumination it produces and its perception are distinct concepts.
What robots and AI may and may not do Filled
Must not
- Shine light into people's eyes or use it to dazzle drivers or pilots.
- Switch off lighting that people need for safe movement, such as on stairs or exits.
- Use flashing light in ways that can trigger seizures.
Only with a human decision
- Changing light exposure in shared or public spaces.
May
- Explain the properties of light and its interactions with matter.
- Measure and report light properties using instruments it is authorized to use.
- Switch and dim light sources the agent is authorized to control.
Moral aspects Filled
- Light pollution harms sleep, wildlife and the night sky.
- Lighting affects safety and the feeling of safety, unequally across neighbourhoods.
Who is affected
- People in the space
- Neighbours
- Nocturnal wildlife
Owners Filled
Steward
No single steward owns light as a physical phenomenon; operators are responsible for the light sources they control.
Links to other meta-models Filled
parent
- Q11386 - registry parent class
- Q2646911 - registry parent class
related
- lamp - the fitting is a device; the light is a condition
- room - requirements attach to places and tasks
- electric power - watts describe consumption, lumens describe output, and they are not proportional across technologies
- workplace lighting standards - minimum levels for tasks and escape routes
What else AI and robots need to interact with it Filled
Identity and identifiers required Filled
- Vercy registry: vr.tr.light
- Wikidata: Q9128 (https://www.wikidata.org/wiki/Q9128)
- SI unit: lux, lumen, candela three different quantities that are constantly substituted for one another
Direct properties not applicable Not applicable
- illuminance: 0.1-100000 lux - from moonlight to direct sun; workplaces are typically 300-750
- colour temperature: 2000-6500 K
- colour rendering index: 60-100 Ra - matters wherever colour judgement is part of the task
- visible wavelength: 380-750 nm
Plane ACT: no invented physical properties.
Recognition optional Filled
- Visible light can produce colour and brightness sensations when it reaches the eye.
- Near-visible infrared and ultraviolet radiation cannot generally be identified by unaided human vision.
- Colour appearance alone does not reliably identify a light source or its spectrum.
- Illuminance describes light incident on a surface, while luminance describes directional light from a source or surface.
- Not a thing seen but the condition of seeing. What is observed is a source, a lit surface or a shadow.
Capabilities and actions required Filled
- see by it, which is what almost every requirement about it is really about
- measure it, at a point and on a surface
- produce it, block it, filter it and reflect it
- be harmed by it - glare, ultraviolet, laser exposure
- signal with it, which is a different use with different requirements
Hazards and failure modes required Filled
- Glare can reduce visibility even when measured illuminance rises.
- Flickering light can cause discomfort and trigger seizures in susceptible people.
- Ultraviolet exposure from unshielded sources and the sun can harm people.
- Light pollution can disrupt sleep and nocturnal wildlife.
Standards and interfaces required Filled
- CIE publications, which define the photometric quantities themselves
- EN 12464 and its national equivalents, which set workplace lighting levels
- Emergency lighting standards, which set minimum levels on escape routes
- Laser safety classification, which governs sources that can injure at a distance
Context of use required Filled
- Making things visible, and beyond that: signalling, growing plants, disinfecting, carrying data and setting the rhythm of a day.
- by source: daylight, incandescent, fluorescent, LED, discharge, laser
- by purpose: general, task, emergency, signalling, growing, disinfection
- by measure: illuminance, luminance, luminous flux, intensity
Sources Filled
- Wikidata item Q9128: light - identity and sense of the item
- Wikipedia: Light - general description of the item
Open questions
- Should the registry model light as a condition, the fitting as a device, and the requirement as a rule - three linked models rather than one?
- How should daylight be represented, given that it varies continuously and is what most requirements assume?
- What is the right way to record a lighting measurement so its position, direction and time survive with it?
Machine files
Provenance
thing registry research (pass 2) · unreviewed
Built from: models/things/publications/thing-q9128/spec.json