FLASHCARDS! Google Maps, Waze, and the Science of Map Distortion
A Problem You’ve Already Noticed
Think back to the last time you used a map. It was probably this morning when you were trying to find your way through traffic to get to work on time. Whether it’s Google Maps, Apple Maps, Waze, or the GPS in your car, we trust these tools to get us from point A to point B in the quickest way possible. But did you know that each one of these maps, as well as the globes in your homes or classrooms, has been distorted? And it’s not because the engineers and cartographers are bad at their jobs, but because maps must bend for accuracy.
When you look at a globe and see a country like Greenland that looks twice the size of Africa, consider that Africa could fit fourteen Greenlands inside of it. That’s the distortion that you are seeing. And these aren’t mistakes. They’re the unavoidable side effects of flattening a round world onto a flat surface. The Earth is spherical, but maps are flat. Turning one into the other is like peeling an orange and trying to press the peel perfectly flat. Somewhere, the peel must stretch, rip, or bunch. That’s distortion.
Why the Math Says It’s Inevitable
In 1827, mathematician Carl Friedrich Gauss proved in his Theorema Egregium that you cannot take a curved surface and flatten it without changing something. On a map, those “somethings” are shape, area, distance, or direction. You can preserve some elements on the map, but never all four at the same time.
Every map you look at is a compromise. The only question is: what did the mapmaker decide to keep accurate, and what parameters did they choose to let go?
The Mercator Projection: Helpful for Sailors, Misleading for Size
One of the most famous projections is the Mercator, created in 1569 by Gerardus Mercator. It became a hit with sailors because it preserved angles perfectly, making navigation simple. Draw a straight line on a Mercator map, follow that compass bearing, and you’d reach your destination.
The trade-off? As you move away from the equator, the map stretches vertically. Greenland looks huge. Alaska rivals Brazil. Canada looms like a giant hat over the northern hemisphere. In reality, they’re much smaller.
This wasn’t political trickery; it was geometry. But because Mercator maps hung in classrooms for decades, they subtly reinforced an inflated sense of the size, and perhaps the importance, of certain northern countries.
Trying to Be Fair: The Gall–Peters Projection
By the 1970s, some geographers wanted something fairer. The Gall–Peters projection keeps the area of countries proportional. On this map, Africa and South America appear as massive as they truly are. But the shapes look stretched and a bit odd.
People weren’t used to seeing the world that way, so it felt “wrong,” even though the math was correct. That’s the power of habit. Once you’re used to one kind of distortion, another kind feels like a mistake.
Different Maps for Different Jobs
Not all projections serve the same purpose. Airline route maps often use azimuthal projections, which preserve direction from one point. Many regional maps use conic projections, balancing shape and area for mid-latitude countries. The Robinson projection, which National Geographic adopted in the late 1980s, is a compromise that doesn’t preserve any single quality perfectly, but it looks good overall.
Then there’s Buckminster Fuller’s Dymaxion map, which unfolds the globe into triangles to minimize distortion and tosses the whole “north on top” idea out the window.
Your GPS Still Distorts
You might think digital maps have solved this. Not quite. Most online maps, including Google Maps, use Web Mercator, a variation of the Mercator that’s easy for computers to process. At street level, it’s accurate enough that you won’t notice. But zoom out to see the whole Earth, and you’ll find Greenland is still too big.
Why Distortion Matters
Map distortion isn’t just a trivia fact; it shapes how we think about the world. Maps can make some countries look larger and more central, subtly influencing how we see their importance. Even deciding which part of the world gets placed in the center of a map can reflect the mapmaker’s culture and perspective.
Maps are not neutral. They’re both tools and stories, revealing not just where things are, but how someone chose to show them.
A Simple Reality Check
Here’s an easy trick: the next time you look at a world map, compare Greenland to Africa. If they look close in size, you’re looking at a projection that values shape over area. And that’s fine, as long as you know it.
Three Takeaways
First: All maps distort; it’s mathematically impossible to make a perfectly accurate flat map of a round Earth.
Second: The projection a mapmaker chooses tells you what they value, whether it’s navigation, proportional size, or a pleasing overall look.
Third: The way a map is drawn can influence your perception of geography, culture, and even politics. Awareness is your best defense.
That’s it for Flashcard Friday! I’m Gabrielle, and if you enjoyed today’s episode, subscribe to Math! Science! History! wherever you get your podcasts. Until next time, carpe diem!