Oeratoom (Primeval Atom) - Big Bang in Leuven

Explore the Big Bang Theory through the heart of Leuven

The Oeratoom - Big Bang in Leuven is a Quick App that promotes the urban artwork in Leuven in tribute to Georges Lemaître, the father of the Big Bang Theory and the founder of modern cosmology. Lemaître studied physics and mathematics in Leuven, followed by theology. In 1931, Lemaître introduced the revolutionary Big Bang Theory at the university of Leuven.

This application has been created to complement the great artwork, promoted by KU[N]ST Leuven. The artwork was performed by the artist Félicie d’Estienne d’Orves. She transforms scientific knowledge into poetic images that make us ponder our place in the universe. This application wants to help visitors understand this master piece.

It’s free, open-source and collaborative

Some screenshots:

Screenshots of the application


This app is based on open data (mainly Wikidata) and automatic processing of the data. The community’s content is enriched and curated, so it’s available to anyone who wants to get involved. Local experts are welcome to refine the definitions, names, and pictures.

We care for your privacy. The app doesn’t collect any personal data, so relax.

Perhaps the content is inaccurate, so please let us know if you’ve spotted anything that might be enhanced.

Get involved

Do you want to contribute to the content?

The content is stored in this repository, so you can look at the existing information.

There are two resource types:

You can download it in your computer, modify the texts, or add a new element based on your knowledge. You can upload it directly (better a Pull Request if you are familiar with GitHub), or raise an issue to suggest the changes (please be explicit).

Note that there is a moderation process (just to avoid spam), so it may take some hours. Please, leave a note with the suggestion, so the editor may validate and confirm your changes.

How to submit new images

The images are in the ./images directory.

You can find a mistake, or you want to modify and upload a new version.

If you have new images to add, just upload your new ones in the folder.

Please, use the identifier of the point of interest you are referring to (see attribute id of the Point of Interest).

How to update the database?

The database is in a JSON file named data.json in the root directory of the project.

Please be sure that this document has the correct format (syntax and content). You can test it using any JSON schema validation tool against the JSON schema you can find in the repository (schema.json).

This JSON document contains two main parts, represented by the main keys of the root object:

  1. meta: metadata about the project
  2. content: multilingual content and setup of the application (based on localized information)

Metadata of the project

Example of a project named fr/paris for the City of Paris:

    "meta": {
        "app_title": "Oeratoom Leuven",
        "version": 3,
        "updated": "2022-08-26",
        "source_url": "https://ow2-quick-app-initiative.github.io/poi-quick-app-implementations/be/leuven/oeratoom/data.json",
        "analytics_id": "1",
        "marketplace_url": ""
    "content": {
        "en": {},
        "fr": {},
        "es": {}

Content of the project

Continuing with the example of City of Paris, we can localize in any language, using the ISO 639-1 codes (assigning a two-letter code for the language). You can also specify the concrete region (using a - character and the concrete ISO 3166-1 (Alpha-2 code).

    "meta": {},
    "content": {
        "en_GB": {},
        "en_US": {},
        "fr": {},
        "es": {}

The project must contain at least one language tag.

Every key of the content object is a language tag that must contain JSON objects with the same keys but with different translations and content localized according to the language.

The content language tags are objects with the following structure:

    "meta": {},
    "content": {
        "LANG": {
            "app": {},      // App configuration (color, texts)
            "pois": []      // Points of Interest
    "meta": {},
    "content": {
        "en": {
            "app": {
                "theme": {
                    "brand": "#37423C",
                    "complementary": "#F99B93"
                "repository_url": "https://github.com/ow2-quick-app-initiative/poi-quick-app-implementations/tree/main/docs/oeratoom/",
                "text_info": "In Leuven... Discover many interesting facts about the work of art and the universe while walking.",
                "text_acknowledge": "This quick app is an open-source project powered by open data from the City of Leuven and enriched by Wikidata information. Most of the information was extracted from https://www.visitleuven.be/oeratoom and Wikimedia. You can find inaccuracies, so we apologize in advance.",
                "text_feedback": "Please let us know if you want to contribute with your experience, enrich the content, correct inaccuracies, or submit pictures. This app is created by locals and experts.",
                "feedback_url": "https://ow2-quick-app-initiative.github.io/poi-quick-app-implementations/be/leuven/oeratoom/#get-involved",
                "issue_url": "https://github.com/ow2-quick-app-initiative/poi-quick-app-implementations/issues/new?template=update_request.md&title=Update+Request"
            "pois": [
                "id" : "Q2469",
                "type" : "Spiral",
                "lon" : "4.7024098",
                "lat" : "50.8791264",
                "name" : "M31 - ANDROMEDA GALAXY",
                "constellation" : "Andromeda",
                "years" : "13.78 billion years",
                "description" : "Age: 13.78 billion years. Galaxy in the constellation of Andromeda",
                "discoverers" : null,
                "discovery" : "0964",
                "radius" : 10000000000000,
                "loc" : "sh85004924",
                "freebase" : "/m/0jvb4",
                "catalogue" : "2557",
                "quora" : "Andromeda-Galaxy-3",
                "more" : "",
                "images" : ["https://upload.wikimedia.org/wikipedia/commons/thumb/8/8c/Andromeda_Galaxy_560mm_FL.jpg/600px-Andromeda_Galaxy_560mm_FL.jpg"],
                "attributions": ["Source: visitleuven.be/oeratoom", "Wikimeda, Wikimedia Commons", "Caltech or AAO/ROE" ],
                "wikidata": "Q2469", 
                "urls": []
                    // Other PoI...
App configuration

The app can be configured with localized texts, URLs and themes, depending on the user’s locale. Each language tag in the content member has an object to configure and customize the application (app key). You can customize it through the following members:

Points of Interest

The PoIs are the main items of the database, described in the poi attribute as an array of objects with the following members:

How to configure and handle public update proposals

By default, any user’s feedback is handled through GitHub issues. In order to facilitate the moderation, issues will be classified using tags to indicate the project whose belong to. The title of the issues should contain the same name or identifier of the point of interest to avoid misunderstandings.

You also can create an issue template to have homogeneous format (see .github/ISSUE_TEMPLATE/update_request.md) and use it for new issues.

In the app configuration we configure the template URL for the issues for the project. If you want to handle issues by language, you can specify different tags or templates according to your needs.

For instance,

    "issue_url": "https://github.com/ow2-quick-app-initiative/poi-quick-app-implementations/issues/new?labels=sample&template=update_request.md&title=Update+request+of+"

Note that the application will append the name of the point of interest at the end of the URL, so the GitHub issue will contain the full name of the point of interest in the title.


Do you want to contribute to the code?

Just fork the repository and start sending your contributions. The code of the quick app is in the /quick-app folder of the repository.

Feel free to raise issues on the code.