buc.ci is a Fediverse instance that uses the ActivityPub protocol. In other words, users at this host can communicate with people that use software like Mastodon, Pleroma, Friendica, etc. all around the world.

This server runs the snac software and there is no automatic sign-up process.

Admin email
abucci@bucci.onl
Admin account
@abucci@buc.ci

Search results for tag #topology

0 ★ 0 ↺

[?]Anthony ยป 🌐
@abucci@buc.ci

For reasons that aren't even clear to me, I'm about 1/3rd into Barry Jay's Reflective Programs in Tree Calculus and about 1/10th into Frank Waaldijk's Natural Topology, which I've been reading side-by-side. Smashing these two into each other is pretty fascinating, even as I'm not sure what to make of the mixture yet.

Having sat with the notion for about six months now, I think Jay's critique of the Church-Turing thesis has legs. I don't see clearly yet exactly where and how the limits of computation manifest in his own system(s), which of course they must. But I think he's correct that this thesis as it's colloquially presented (and taught to students, including me!) is misleading at best and false in a certain important sense. Apparently he is regularly called a crackpot for forwarding this critique even though it's straightforwardly demonstrated.

Waaldijk's book is more of a constructive mathematics exploration. In this it is closely related to computer science, but it's focused on traditionally mathematical notions like topological space. The latter is usually quite complicated, but Waaldijk shows that the core concept of compact space can be represented with finitely-branching trees, making these spaces amenable to computation. Since we imagine physics taking place in spaces that are topological (among other things) there's potentially an interesting bidirectional flow of ideas between computer science and physics.

Jay calls his central notion "natural trees". Waaldijk calls his central notion "natural spaces". In both cases I think the intended sense is "with minimal artifice".


    [?]Bruce MacDonald ยป 🌐
    @rationaldoge@hachyderm.io

    Well done and thorough article on gift-wrapping stratagems evidently aimed at a population more versed in math(s) than we are. Informative and entertaining.

    "When you place your gift onto the paper, rotate it so it sits diagonally in the centre of the paper. Then carefully bring the four corners of the paper into the centre, tucking in the tabs at each corner of your box under the larger flaps as you fold them in. You should be able to secure the paper with just three small pieces of tape, and if you're using stripey paper, the pattern may even match up at the joins."
    bbc.com/future/article/2025121

      AodeRelay boosted

      [?]buherator ยป 🌐
      @buherator@infosec.place

      Weird #DIY question:

      I'd like to have easy to switch paper disks on an axis. An "obvious" solution would be to cut pices of a spiral where the beginning and the end just overlap, so they only get off when turned to the direction of the axis.

      But how do I cut/produce such pieces so that they remain flat when on the axis?!

      #topology

      Dr. Zoidberg: You kids and your topology!

      Alt...Dr. Zoidberg: You kids and your topology!

        AodeRelay boosted

        [?]Simon ๐Ÿฎ:spot: ยป 🌐
        @Firesphere@cloudisland.nz

        Does anyone know of a slightly half-decent Mapping bit of that I can use to make a drawing of my home network?