Answer: Coastlines

There are very few things in the universe that, upon measuring them with higher precision and attention to detail, become longer. Coastlines, however, are a paradoxical example of just that: a thing that increases almost continuously in length the longer you spend measuring it. But how can it be that a coastline is longer the more time you spend measuring it? Coastlines of land masses have fractal-like properties. Very few coastlines are straight for any significant distance and the more time you spend measuring a coastline with ever increasing accuracy, the longer the length of the measurement becomes.

A rather mind blowing example of this is the fact that the coastline of the U.S. state of Maine is longer than the coastline of California. At first glance, that seems preposterous given that California’s coastline takes up more than half the entire west coast of the United States while Maine is just a little projection in the upper northeast portion of the lengthy east coast. But when you drill down to a granular level and trace the coastline of Maine in detail (including the numerous tidal flats, curves, and projections), the total tidal shoreline of Maine is 3,478 miles long. Yet the “general shoreline” as recognized by the National Oceanic and Atmospheric Administration is a scant 228 miles, because they don’t measure the coastline with that degree of accuracy and in-depth examination.

And that, right there, is the heart of the coastline paradox. With enough time and accurate surveying of a coastline using a small enough unit of measurement, you will quickly find that the length of the coastline you’re surveying increases significantly because you’re measuring every curve, inlet, fjord, outcropping, and small projection. Making the effort to measure around even a single large boulder projecting out into the sea, for example, could easily add a hundred feet to a coastline and taking the time to measure, well, hundreds of such projections would add hundreds upon hundreds of feet to the final total. This paradox is why different organizations around the world (and even within a country) can arrive at different lengths for the coastlines of their own property and other countries.