How Long Is the Coast of Britain? (1967)

(jstor.org)

27 points | by Hooke 3 days ago

5 comments

  • 2b3a51 4 hours ago
    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.

    • paradox460 3 hours ago
      Infinitely long. You can't trick me with the coast paradox
      • _ache_ 49 minutes ago
        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.
        • saghm 13 minutes ago
          Unbounded, at least. If you give me a measurement, I can give you a larger one that's more precise.
        • theodric 49 minutes ago
          This guy* Mandelbrots

          *presumably, but maybe not

        • tiku 2 hours ago
          Depends on your measurements. If you measure with 1 cm it is longer than if measure with 10 cm.
          • ck2 49 minutes ago
            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

            • twocommits 2 hours ago
              [flagged]
              • 2b3a51 1 hour ago
                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).

                • gib444 57 minutes ago
                  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.