Spatial Illusions in APEX: How Map Projections Twist Reality

When working with maps in Oracle APEX, we often assume that what we see reflects reality. But surprisingly, what you see on a map might be very far from the truth.

Let’s take an example: on many world maps, Greenland looks almost as big as Africa - sometimes even bigger. But when we measure the real size, the difference is massive.

Using a Distance Tool, we can see that:

• The height of Africa (north to south) is approximately 8,182.6 km

• The height of Greenland is only about 2,548.1 km

Clearly, Africa is more than fourteen times greater than Greenland. So why does Greenland look so big on the map?

It’s All About Map Projections

To understand the problem, we need to start with a basic fact: The Earth is round, but maps are flat.

To display the surface of a 3D sphere (like the Earth) on a 2D map, we need to "unwrap" or "flatten" the globe. This process is called a map projection.

Unfortunately, it's impossible to flatten a sphere without causing some distortion. Think of peeling an orange and trying to lay the skin flat - it doesn't fit perfectly. You either have to cut, stretch, or compress parts of it. This is exactly what happens when we project the Earth onto a flat map.

Every map projection tries to preserve some aspects of the Earth - like shape, area, distance, or direction - but none can preserve everything at once.

Visualizing the Problem

One way to understand this is by visualizing it. Imagine the globe cut into pieces and opened up like petals or flattened like puzzle parts. That’s what map projections do - they try to lay the Earth flat in different ways.

Some projections cut the oceans to better preserve land shapes. Others distort the poles to keep directions correct for navigation.

Types of Projections

Over the years, many different types of projections have been developed. Each has its strengths and weaknesses. Let’s look at a few:

• Mercator - Probably the most famous projection, especially in online maps. It preserves angles and direction, which is great for navigation, but it massively enlarges areas near the poles. That’s why Greenland appears so large.

• Gall-Peters - This one keeps the area proportional, so Africa appears much larger (as it should), but the shapes of countries may look stretched or distorted.

• Goode Homolosine - Splits the oceans to reduce distortion on continents. Good for thematic maps, less intuitive for navigation.

• Waterman Butterfly - An artistic solution that unfolds the globe like a butterfly. It preserves both shape and area fairly well but is rarely used in common mapping tools.

• Robinson - A compromise projection that balances shape and size. It looks nice and is often used in world maps for display purposes.

What About Oracle APEX?

When we use maps in Oracle APEX - for example with Map Regions - we’re using a web mapping system that relies on a standard projection called Web Mercator, also known as EPSG:3857.

This projection is used by popular platforms like Google Maps or OpenStreetMap. It's fast and works well for dynamic, interactive maps - but it comes with the same distortion problems mentioned earlier.

So next time you're building a map in APEX and wondering why Greenland looks so big, you’ll know it’s not a data error - it’s just the projection doing its job :)

Problems Caused by Using the Wrong Projection

Choosing the wrong map projection can lead to serious misunderstandings - especially in applications that rely on accurate spatial data, like logistics, urban planning, environmental studies, or business dashboards.

Here are some common problems caused by using the wrong projection:

1. Wrong Area Comparisons

2. Incorrect Distance Measurements

3. Wrong Shape Interpretation

4. Poor Spatial Analysis Results

5. Map Clutter and Visual Confusion

What’s Next?

In my next article, I’ll talk about Coordinate Reference Systems (CRS) - the systems that allow maps to know where things are on Earth.

We'll cover:

• What latitude and longitude really mean

• How coordinates are stored and understood in APEX

• The difference between EPSG:4326 and EPSG:3857

Stay tuned!