alt.hn

2/24/2026 at 11:14:16 PM

How Long Is the Coast of Britain? (1967)

https://www.jstor.org/stable/1721427

by Hooke

2/28/2026 at 6:34:05 PM

https://gsp.humboldt.edu/OLM/courses/GSP_510/Articles/Mandel...

Link to a pdf file that you don't need an institutional login for.

I did an activity in a basic maths class based on this paper years ago. Each student had an A3 map of the main island of the UK. Some set their compasses to 5cm radius and counted the number of radii around the island. Others tried 2.5cm, and 1cm and half a cm. Worked ok, good lesson.

by 2b3a51

2/28/2026 at 8:02:57 PM

Infinitely long. You can't trick me with the coast paradox

by paradox460

2/28/2026 at 10:16:56 PM

Actually ... Not infinitely long. You wont have a precise value since each measure can be increased by taking a smaller "step" or "ruler", but it won't be infinite.

by _ache_

2/28/2026 at 10:52:01 PM

Unbounded, at least. If you give me a measurement, I can give you a larger one that's more precise.

by saghm

2/28/2026 at 10:16:06 PM

This guy* Mandelbrots

*presumably, but maybe not

by theodric

2/28/2026 at 10:16:15 PM

ah the coastline paradox

https://en.wikipedia.org/wiki/Coastline_paradox

where the sampling rate affects distance measured

this is also why the GPS on your watch will reports different distances the more frequently it samples, ie. once per second vs once per every few seconds, think curves becoming diagonal lines

it's also why they measure official distances using a wheel on a stick

by ck2

2/28/2026 at 9:03:47 PM

Depends on your measurements. If you measure with 1 cm it is longer than if measure with 10 cm.

by tiku

2/28/2026 at 8:49:58 PM

[flagged]

by twocommits

2/28/2026 at 9:33:42 PM

There is a lot of coastline and not that many police/coastguards. In fact we have been closing down the coastguard stations since satellite tracking of commercial shipping became the norm.

(I come from a part of the UK that was notorious for smuggling, wrecking and other forms of piracy).

by 2b3a51

2/28/2026 at 10:08:49 PM

They're referring to the aslyum seekers (groan)

605 on 10 boats just 3 days ago...

FWIW it's a political problem, not a defence problem.

by gib444