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Why it’s impossible to measure England’s coastline

bbc.com

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Re: Why it’s impossible to measure England’s coastline

#21

Post by bryanrasmussen »

kelnos wrote: post #10
alistairSH wrote: post #5

tl;dr - for the same reason as any other coastline or complex border. Also, it annoys me that the trail in question is advertised as allowing one to walk the entire English coast - but fails to mention Wales and Scotland are in the way (the trail is not contiguous).

Assuming they specifically do advertise that you can walk the entire English coast, then it is accurate, as Wales and Scotland are not England.

unless they have edited they do not say Wales and Scotland are England, they complain the trail is not contiguous, which to be fair might also be implied by the fact that Wales and Scotland are not England but I guess I could see a scenario that allowed made the trail contiguous, which would still allow you to walk the English coast, but also of course allow you to walk some other parts that are not on the coast.

Re: Why it’s impossible to measure England’s coastline

#22

Post by colechristensen »

linzhangrun wrote: post #19
Lucasoato wrote: post #7

This article says that by using a smaller unit of measure, the measured coastline increases. The concept of dimension in fractals is backed by a similar idea! Take the Koch curve for example, at any iteration it gets longer and its 1-dimensional length loses the usual meaning because it diverges to infinity as you continue iterating. Intuitively the fractal dimension allows you to calculate how fast the measurement i…

[flagged]

The meaning of "coastline" breaks down far before you reach quantum levels. I challenge you to go to the beach and pick a square inch where the "coastline" splits it half and half, this part England, that part the sea.

Re: Why it’s impossible to measure England’s coastline

#23

Post by sjshdhs »

colkassad wrote: post #3
jstanley wrote: post #2

I was thinking about this recently, the way to do is to define a radius, and then imagine rolling a circle of that radius around the outside of the coastline (or around the inside! Define that as well) and then take the length of the equivalent track that never leaves contact with the circle. So you get a different length depending on the radius you choose, but at least you get an answer. You could define the radius…

A radius of plank length is the only true answer

Plank's length is an ok answer, but coast line reaches a steady state way before that. Nature only has approximate fractals.

Way before plank length you'll get the surface and line energies of the material interfaces dominating the total energy. Those tend to force very smooth and very discreet lengths.

Re: Why it’s impossible to measure England’s coastline

#24

Post by hulitu »

sota_pop wrote: post #12

How on earth can you write an article that practically plagiarizes the title, mention the paradox, and neither mention mandelbrot nor cite the original paper anywhere!? https://www.researchgate.net/profile/Ion-Andronache/post/Wha...

It is the BBC. They are so busy with propaganda, that any act of thinking, hurts.

Re: Why it’s impossible to measure England’s coastline

#25

Post by vidarh »

avazhi wrote: post #13

I guess I could understand why this would be borderline impossible if you did it manually, but surely today with satellite images and computer vision it really shouldn’t be that difficult to agree on a standard unit and then just automate it. Surely just make the scale human at its smallest (meters works and can get converted from there, assuming you have sufficient zoom level data for the coastline) and call it a da…

The article is not about practical measurements at all. Doing it manually has nothing to do with it. It is explicitly about why the measured length depends on the precision you choose to measure with.

Re: Why it’s impossible to measure England’s coastline

#27

Post by barnabee »

thebruce87m wrote: post #26

> A new hiking trail will soon allow travellers to walk around England's entire coast This is a strange concept as there are two countries that share a land border so how do they manage the “gaps”?

The Wales Coast Path[0] links up with it, so (aside from the small gap in Cumbria), you can walk all the way round if you start and end at the Scottish border.

There’s also the Hadrian’s Wall Path[1] that allows you to link back into a loop new the Scottish border, though it misses out a section of the English coast in the North East.

[0] https://en.wikipedia.org/wiki/Wales_Coast_Path [1] https://en.wikipedia.org/wiki/Hadrian%27s_Wall_Path

Re: Why it’s impossible to measure England’s coastline

#28

Post by owenm »

thebruce87m wrote: post #26

> A new hiking trail will soon allow travellers to walk around England's entire coast This is a strange concept as there are two countries that share a land border so how do they manage the “gaps”?

Three countries - England, Scotland, Wales.

Re: Why it’s impossible to measure England’s coastline

#30

Post by dfawcus »

barnabee wrote: post #27
thebruce87m wrote: post #26

> A new hiking trail will soon allow travellers to walk around England's entire coast This is a strange concept as there are two countries that share a land border so how do they manage the “gaps”?

The Wales Coast Path[0] links up with it, so (aside from the small gap in Cumbria), you can walk all the way round if you start and end at the Scottish border. There’s also the Hadrian’s Wall Path[1] that allows you to link back into a loop new the Scottish border, though it misses out a section of the English coast in the North East. [0] https://en.wikipedia.org/wiki/Wales_Coast_Path [1] https://en.wikipedia.org/wik…

A section? All of Northumberland, as Wallsend is in Tyne and Wear.

The task of walking (or measuring) the whole of England's coastline is made a bit more difficult by the existence of various islands classed as part of England.

e.g. Isle of Wight, St. Mary's Island, Coquet Island, Lindisfarne, the other Farne islands, etc.

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