# How the James Webb telescope makes a picture

> A process map exported from forks.world (https://forks.world). Author: Brian. Source: https://forks.world/p/cmv0kpx3b000jjv06tyihblh6
> It describes who does what, in what order, and with which technology. Read the plain-language sections first; the JSON at the end is the exact, complete data.

## Summary

- 13 steps across 2 layers
- Persona: Astronomers, The public
- Technology / systems: Distant light, The telescope

## How to read this file

- A process is made of **layers**. The main layer is the top level; any step of kind `subprocess` opens a detail layer with its own lanes and steps.
- **Lanes** are either persona (people/roles) or technology (systems). Each step belongs to one lane; `using` lists tools a person uses for that step.
- Step kinds: `start`, `task`, `decision` (its arrows carry the answer as a label), `subprocess`, `end`.

## How the James Webb telescope makes a picture

Lanes:
- Distant light: technology / system (id `sky`)
- The telescope: technology / system (id `scope`)
- Astronomers: person / role (id `team`)
- The public: person / role (id `press`)

Steps, in the order they run:

1. **Ancient infrared light travels for billions of years** [start; Distant light; id `j1`]
   - then A gold mirror made of 18 segments collects it
2. **A gold mirror made of 18 segments collects it** [task; The telescope; id `j2`]
   - then A giant sunshield keeps it cold so heat does not drown the signal
3. **A giant sunshield keeps it cold so heat does not drown the signal** [task; The telescope; id `j3`]
   - then Instruments split the light into data
4. **Instruments split the light into data** [task; The telescope; id `j4`]
   - then Raw data comes down from a million miles away
5. **Raw data comes down from a million miles away** [task; Astronomers; id `j5`]
   - then Calibrate and clean it
6. **Calibrate and clean it** [task; Astronomers; id `j6`]
   - then Infrared is invisible: which colors to show?
7. **Infrared is invisible: which colors to show?** [subprocess; Astronomers; id `j7`], opens the detail layer "Choosing colors"
   - then Assemble the image
8. **Assemble the image** [task; Astronomers; id `j8`]
   - then Release: a picture of the early universe
9. **Release: a picture of the early universe** [end; The public; id `j9`]

```mermaid
flowchart LR
  subgraph l_sky["Distant light"]
    n_j1(["Ancient infrared light travels for billions of years"])
  end
  subgraph l_scope["The telescope"]
    n_j2["A gold mirror made of 18 segments collects it"]
    n_j3["A giant sunshield keeps it cold so heat does not drown the signal"]
    n_j4["Instruments split the light into data"]
  end
  subgraph l_team["Astronomers"]
    n_j5["Raw data comes down from a million miles away"]
    n_j6["Calibrate and clean it"]
    n_j7[["Infrared is invisible: which colors to show?"]]
    n_j8["Assemble the image"]
  end
  subgraph l_press["The public"]
    n_j9(["Release: a picture of the early universe"])
  end
  n_j1 --> n_j2
  n_j2 --> n_j3
  n_j3 --> n_j4
  n_j4 --> n_j5
  n_j5 --> n_j6
  n_j6 --> n_j7
  n_j7 --> n_j8
  n_j8 --> n_j9
```

### Choosing colors (detail of step "Infrared is invisible: which colors to show?")

Lanes:
- Astronomers: person / role (id `team`)

Steps, in the order they run:

1. **Map the longest infrared wavelengths to red** [start; Astronomers; id `c1`]
   - then Map the shortest to blue
2. **Map the shortest to blue** [task; Astronomers; id `c2`]
   - then The goal is to show structure, not "true color"
3. **The goal is to show structure, not "true color"** [task; Astronomers; id `c3`]
   - then The image stays scientifically honest
4. **The image stays scientifically honest** [end; Astronomers; id `c4`]

```mermaid
flowchart LR
  subgraph l_team["Astronomers"]
    n_c1(["Map the longest infrared wavelengths to red"])
    n_c2["Map the shortest to blue"]
    n_c3["The goal is to show structure, not 'true color'"]
    n_c4(["The image stays scientifically honest"])
  end
  n_c1 --> n_c2
  n_c2 --> n_c3
  n_c3 --> n_c4
```

## Full data (JSON)

```json
{
  "title": "How the James Webb telescope makes a picture",
  "maps": {
    "m_root": {
      "id": "m_root",
      "lanes": [
        {
          "id": "sky",
          "name": "Distant light",
          "type": "system"
        },
        {
          "id": "scope",
          "name": "The telescope",
          "type": "system"
        },
        {
          "id": "team",
          "name": "Astronomers",
          "type": "person"
        },
        {
          "id": "press",
          "name": "The public",
          "type": "person"
        }
      ],
      "steps": [
        {
          "id": "j1",
          "kind": "start",
          "lane": "sky",
          "next": [
            {
              "to": "j2"
            }
          ],
          "uses": [],
          "label": "Ancient infrared light travels for billions of years"
        },
        {
          "id": "j2",
          "kind": "task",
          "lane": "scope",
          "next": [
            {
              "to": "j3"
            }
          ],
          "uses": [],
          "label": "A gold mirror made of 18 segments collects it"
        },
        {
          "id": "j3",
          "kind": "task",
          "lane": "scope",
          "next": [
            {
              "to": "j4"
            }
          ],
          "uses": [],
          "label": "A giant sunshield keeps it cold so heat does not drown the signal"
        },
        {
          "id": "j4",
          "kind": "task",
          "lane": "scope",
          "next": [
            {
              "to": "j5"
            }
          ],
          "uses": [],
          "label": "Instruments split the light into data"
        },
        {
          "id": "j5",
          "kind": "task",
          "lane": "team",
          "next": [
            {
              "to": "j6"
            }
          ],
          "uses": [],
          "label": "Raw data comes down from a million miles away"
        },
        {
          "id": "j6",
          "kind": "task",
          "lane": "team",
          "next": [
            {
              "to": "j7"
            }
          ],
          "uses": [],
          "label": "Calibrate and clean it"
        },
        {
          "id": "j7",
          "kind": "subprocess",
          "lane": "team",
          "next": [
            {
              "to": "j8"
            }
          ],
          "uses": [],
          "child": "m_color",
          "label": "Infrared is invisible: which colors to show?"
        },
        {
          "id": "j8",
          "kind": "task",
          "lane": "team",
          "next": [
            {
              "to": "j9"
            }
          ],
          "uses": [],
          "label": "Assemble the image"
        },
        {
          "id": "j9",
          "kind": "end",
          "lane": "press",
          "next": [],
          "uses": [],
          "label": "Release: a picture of the early universe"
        }
      ],
      "title": "How the James Webb telescope makes a picture",
      "parent": null
    },
    "m_color": {
      "id": "m_color",
      "lanes": [
        {
          "id": "team",
          "name": "Astronomers",
          "type": "person"
        }
      ],
      "steps": [
        {
          "id": "c1",
          "kind": "start",
          "lane": "team",
          "next": [
            {
              "to": "c2"
            }
          ],
          "uses": [],
          "label": "Map the longest infrared wavelengths to red"
        },
        {
          "id": "c2",
          "kind": "task",
          "lane": "team",
          "next": [
            {
              "to": "c3"
            }
          ],
          "uses": [],
          "label": "Map the shortest to blue"
        },
        {
          "id": "c3",
          "kind": "task",
          "lane": "team",
          "next": [
            {
              "to": "c4"
            }
          ],
          "uses": [],
          "label": "The goal is to show structure, not \"true color\""
        },
        {
          "id": "c4",
          "kind": "end",
          "lane": "team",
          "next": [],
          "uses": [],
          "label": "The image stays scientifically honest"
        }
      ],
      "title": "Choosing colors",
      "parent": {
        "map": "m_root",
        "step": "j7"
      }
    }
  }
}
```