I remember being told this in high school and being totally confused. My teacher told us that a standard map, or even a globe, is inaccurate. She explained why but I didn’t understand. Why is this?
In: Technology
Imagine a strawberry. Now imagine you were in a situation where the exact distances between the seeds on its surface was of life or death importance to millions of people and you had to draw a picture of it to accurately depict those distances without using any words or numbers. And the map you drew was going to be given to someone who had never seen a strawberry before and didn’t know anything about them. How would you draw that picture?
Imagine you have a balloon and you draw a bunch of same sized dots on it, then you cut a line to define one edge of the balloon and and try to lay it flat like a map. Obviously, you’re going to have trouble simply making it lie flat without tearing or folding (it’s actually impossible to make spheres lie perfectly flat this way), but those dots will also lose some of their clarity, getting bunched up or pulled apart. Considering the stuff where the dots would be on a globe is all of the Earth’s geography, this is a problem.
The most common map in the world gets around this problem by making the dots (ie: the land), at the top and bottom larger to account for the stretching, but this does distort distances (although, conveniently, it means that if you move in a straight line on the map, you also move in a straight line in real life, which is why it was used by so many people). Other maps get around this by stretching or squashing the dots. Each method has its upsides and downsides, but none can perfectly capture all of the information a globe provides at the same time.
Globes are very close to the true shape of the Earth, however the Earth is both slightly flatter than you would think, and also more lumpy. That said, the issues with a globe are much smaller than the issues with any map. You can generally rely on their accuracy.
An example of the dots (known to map makers as a **Tissot indicatrix**) with the most common (Mercator) type of map can be seen below. On a globe, all of the red dots would be the same size:
[https://upload.wikimedia.org/wikipedia/commons/8/87/Tissot_mercator.png](https://upload.wikimedia.org/wikipedia/commons/8/87/Tissot_mercator.png)
Everyone on here talking about mapping a sphere onto a flat surface, but forgetting about all the *human* biases. There’s literally no reason for the southern hemisphere to be the bottom of the map – the Earth floats in space and the universe doesn’t have a right side up
A globe would be inaccurate simply because of its scale. One inch on the globe covers a small country.
A world map is the same + a flat surface can not represent a curved surface as of our planet. You need to stretch certain areas. We decided to stretch the top and bottom leaving equator fairly untouched, but we could have stretched it another direction if we wanted to.
While there are tons of answers here agreeing that standard maps are inaccurate, that is mostly true for maps *of an entire planet*.
What I have not seen written is that there are standard map projection systems that are designed to depict zoomed-in portions of the earth’s surface and which are perfectly accurate enough for navigation, building, and recording scientific data. The USGS uses UTM for topographic maps. Many states or countries or regions have their own systems (i.e., the Florida State Plane system is widely used by surveyors and for presentation of all sorts of geospatial data).
The better system is from state-sized or the like which tend to act as if the equator was moved to near the subject area (the equator is where error on any map is lowest), and these are designed/optimized by professional cartographers to minimize error across the entire system. UTM is kind of a can of worms to explain, but it historically suits the depiction of blocks of surveyed land in a way that is easy to navigate and easy for the navigator to understand its drawbacks (errors), which tend to be small when zoomed-in enough.
I guess my point is that when zoomed-in to a small enough subject area on globe/map, there are projection systems out there that are acurate and reliable enough for the highest level of practical, real-life applications.
Peel an orange. Now, try to shape it into a perfect rectangle. This is the issue even the most sophisticated projection softwares run into when trying to take the globe and project it into a rectangular shape that we see on a classic map.
If you take an orange and peel it, then try to push the peel flat on a table. When you do this you will have gaps and this is why a map cant be accurate.
How this is solved depends on the map, the one you see most frequently essentially puts a cylinder around the globe and the just project what is straight towards the center axis of the cylinder.
Other ways include trying to preserve either shape or distance of the land or the sea
Get a tangerine and peel it all in one piece, then try and squish it flat and you will understand
I don’t know if this can really be explained without using images, or even better, video. There are many videos and animations that explain this really well.
[https://laughingsquid.com/the-problem-with-map-projections-and-why-all-maps-are-wrong/](https://laughingsquid.com/the-problem-with-map-projections-and-why-all-maps-are-wrong/)
This animation displays one of the most accurate flat maps, but North isn’t up.
[https://en.wikipedia.org/wiki/File:Dymaxion_2003_animation_small1.gif](https://en.wikipedia.org/wiki/File:Dymaxion_2003_animation_small1.gif)
*Drags Russia onto US*
*Suddenly realizes how damn long the Trans-siberian is*
Also the size difference between the North and Central Pacific is sneaky, you can cross from LA to Kamchatka using a Russia measuring stick with St Pete in Kamchatka and Vladivostok in LA. Shift St Pete down to Hawaii and Vladivostok can’t make it to Mexico.
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