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Coastline paradox

en.wikipedia.org

21–30 of 111 posts

Re: Coastline paradox

#21

Next time you go to measure your waistline, just remember: have you really put on weight, or is it just the coastline paradox?

This unfortunately doesn't quite work, because while there's no well defined upper bound, there is a lower bound.

true, but you could just argue that any increase was just a result of over-estimating the last time you measured

Re: Coastline paradox

#22
post #4
post #2

Step 1: Acquire small beachfront property Step 2: Put property on the market, listed as having a mile of beach Step 3: ??? Step 4: Profit There's no way this could backfire, unless the buyer asks how big your ruler is. But a true gentleman never questions the size of another's ruler, so you should be in the clear.

> There's no way this could backfire, unless the buyer asks how big your ruler is. Or it goes through a real world court system where judges take very dim views to that level of pedantry...

Yes, the GP was clearly serious in their advice to exploit the coastline paradox in order to mislead would-be buyers! (/s)

Re: Coastline paradox

#24
post #16

It also imples that any border between countries that is defined by a natural border, eg a river is infinitely long, right?

No since water boundaries like rivers are defined as the middle of the river, not as the shifting coast of either side of the river.

Not always. The boundary between VA and MD (states in the USA) is the Virginia shoreline of the Potomac River.

Which has caused oddities over the years…

At one time, gambling and liquor were illegal in VA, so casinos set up boats at the low tide line. Customers parked in VA and walked onto the casino barges from the Va side, but they were technically in MD.

You need to follow MD fishing regulations even from VA shore (though a VA license is ok).

Re: Coastline paradox

#26
post #16

It also imples that any border between countries that is defined by a natural border, eg a river is infinitely long, right?

No since water boundaries like rivers are defined as the middle of the river, not as the shifting coast of either side of the river.

genuine question: how is the middle defined when both shores are fractals?

Re: Coastline paradox

#27
I’ve never taken calculus (the last math class I took was an algebra class in high school in the late 1980s). But I read a description of calculus once that used the example of trying to figure out the length of a coastline and described how one could use smaller and smaller sections to estimate the length and this is what calculus is all about. But, this article doesn’t mention calculus at all, so now I’m wondering if my impression of what calculus is used for is all wrong.

Re: Coastline paradox

#28

I’ve never taken calculus (the last math class I took was an algebra class in high school in the late 1980s). But I read a description of calculus once that used the example of trying to figure out the length of a coastline and described how one could use smaller and smaller sections to estimate the length and this is what calculus is all about. But, this article doesn’t mention calculus at all, so now I’m wondering…

Calculus and why it doesn’t help here are mentioned in the “mathematical aspects” section of the article

Re: Coastline paradox

#29

I’ve never taken calculus (the last math class I took was an algebra class in high school in the late 1980s). But I read a description of calculus once that used the example of trying to figure out the length of a coastline and described how one could use smaller and smaller sections to estimate the length and this is what calculus is all about. But, this article doesn’t mention calculus at all, so now I’m wondering…

Calculus deals with things that are sufficiently smooth on a small scale, and thus converges. For example, approximating a circle with smoother and smoother polygons. The length of those polygons will converge to the circumference of the circle.

The coastline paradox is the classic example of a fractal; the dimension of a fractal is actually greater than that of the space it lives within!

Re: Coastline paradox

#30

I’ve never taken calculus (the last math class I took was an algebra class in high school in the late 1980s). But I read a description of calculus once that used the example of trying to figure out the length of a coastline and described how one could use smaller and smaller sections to estimate the length and this is what calculus is all about. But, this article doesn’t mention calculus at all, so now I’m wondering…

Calculus deals with things that are sufficiently smooth on a small scale, and thus converges. For example, approximating a circle with smoother and smoother polygons. The length of those polygons will converge to the circumference of the circle. The coastline paradox is the classic example of a fractal; the dimension of a fractal is actually greater than that of the space it lives within!

The word converge always confused me here when learning English. It's not like the edges of a circular polygon "converge" even in a hypothetically perfect circle. They more....blend together, or lose their edge. Either way maybe I've never properly understood the term.
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