Why Experts Can't Agree on the Lengths of the World's Coastlines

iStock
iStock

Measuring the distance between two places on a map is pretty straightforward. But if you want to calculate how long a shoreline is, things can get complicated. Just search "U.S. coastline length" and you'll find that results can vary by tens of thousands of miles.

How can cartographers come up with numbers that differ so wildly if they're all measuring the same thing? The answer, according to the video below from RealLifeLore, lies in a phenomenon called the Coastline Paradox.

Measuring the East Coast of the U.S. isn't the same as calculating the miles separating the tip of Florida from the tip of Maine. A coast doesn't follow a straight line. It's made up of divots and curves that start to multiply the closer you zoom in on the map. Accounting for every single detail of the coast is impossible. One, because the shore is always changing shape, and two, because these intricacies go all the way down to the molecular level.

That means cartographers have to pick a unit of measurement with which to estimate the length of the coast. If one team measures in miles and another measures in units of 100 miles, their results will look very different. Smaller measurements produce longer and, technically, more accurate numbers. But at some point, if you keep drilling down to smaller and smaller units, the length of a coastline appears to approach infinity—which doesn't seem entirely right, either. So every measurement of a coastline you see is really just a rough estimate.

The Coastline Paradox isn't the only complication that makes cartography an imperfect science. Even Mount Everest's title as the world's tallest mountain isn't totally uncontested.

Learn more about the Coastline Paradox in the video below.

[h/t RealLifeLore]

Why is North Always Up on Maps?

iStock/Princessdlaf
iStock/Princessdlaf

Geophysicists recently updated the World Magnetic Model—navigational data used for everything from cell phones to satellites—and found that magnetic north, a spot once located in Arctic Canada, is moving quickly toward Siberia. But even this discovery doesn't quite explain why maps always feature north at the top.

There’s nothing inherently upward about north. Some early Egyptian maps put south on top, while in medieval Europe, Christian cartographers tended to give that distinction to east, since you had to turn that way to face Jerusalem. Others placed east on top because of the rising Sun (that’s why we orient ourselves). And early American settlers sometimes used maps with west on top, because that was the direction they were often heading.

If anyone deserves the blame for today’s northward bias, it’s Claudius Ptolemy. In the 2nd century, he wrote the influential Geographia, which featured a “global” map with north on top. No one’s positive why he positioned it that way, but it may be that the Library of Alexandria—where he did his research—simply didn’t have much information on the Southern Hemisphere. During the Renaissance, Ptolemy’s work was revived. By then, the phenomenon of magnetic north had been discovered, making his layout even more appealing to mapmakers.

The magnetic north pole, however, was not located until 1831. On an otherwise disastrous expedition to Arctic, British explorer James Clark Ross discovered the pole—the spot where a compass needle on a horizontal axis points straight down—on the west coast of Canada's Boothia peninsula. "I must leave it to others to imagine the elation of mind with which we found ourselves now at length arrived at this great object of our ambition," Ross recalled. "Nothing now remained for us but to return home and be happy for the rest of our days."

This story was originally published in 2014.

11 Totally Redundant Place Names

The Milky Way galaxy
The Milky Way galaxy
iStock.com/Nick_Pandevonium

East of Lancashire, England lies Pendle Hill, known for its historical association with witch trials, scientific discoveries about air pressure, and religious visions that led to the founding of the Quaker movement. It is also known for having a tautological name. A tautological name has two parts that are redundant, or synonymous. Tautological place names usually come about when more than one language goes into the name. The Pendle in Pendle Hill is derived from Pen-hyll, a combination of the Cumbric word for "hill" and the Old English word for "hill." So Pendle Hill is really "Hill Hill Hill." Here are 11 other redundant place names:

1. Lake Tahoe ("Lake Lake")

This scenic body of water on the Nevada/California border gets its name from a loose pronunciation of dá’aw, a word from the Native American language Washo that means "lake."

2. La Brea Tar Pits ("The Tar Tar Pits")

The animal bones displayed at this California attraction were preserved in la brea, Spanish for the tar.

3. Milky Way Galaxy ("Milky Way Milky")

The general astronomical term galaxy comes from the word the ancient Greeks used to describe the band of light they could see in the night sky, galaxias or "milky."

4. Minnehaha Falls ("Waterfall Falls")

The name for this Minnesota waterfall does not, as the legend has it, mean "laughing water." It comes from the Dakota word for waterfall.

5. Sahara Desert ("Deserts Desert")

The name for this giant expanse of North Africa comes from çaḥrā, the Arabic word for deserts.

6. El Camino Way ("The Way Way")

There's a street in Palo Alto, California called El Camino Way, or "The Way Way." If you drive down it in your Chevy El Camino you will be driving your way down The Way Way in The Way.

7. Avenue Road

The city of Toronto can't claim the foreign language excuse for this tautological street name.

8. Street Road

Nor can this name in Pennsylvania be blamed on foreign language issues.

9. Mississippi River ("Big River River")

Our favorite spelling word is derived from an Ojibwe or Algonquin word for "big river."

10. Faroe Islands ("Sheep Islands Islands")

Faroe comes from the Faroese word Føroyar, literally meaning "sheep islands."

11. East Timor ("East East")

Whether you say East Timor or Timor Leste, it still means "East East." Timor comes from the Indonesian/Malay timur, for "east." One could argue that the name isn't really tautological, however, since Timor is the name for the easternmost island in a chain of islands, and East Timor is the eastern half of that island. So it's a repeated word, but referring to more than one thing.

A version of this list first ran in 2013.

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