Slashdot Mirror


A Model Railroad That Computes

tri44id writes "Several blogs have noted an Austrian team that has built a model train set that is a primitive computer. I have to point out, though, that it's actually only a Finite State Machine, like a pocket calculator, not a general-purpose device. Their plan for a general purpose layout is for an infinite-state machine, not a FSM+tape that Turing envisioned in his original paper. Turing took the concept a further step, by presenting a Universal Turing Machine that embodies a special set of states and transitions that allows its tape to be programmable to emulate any other TM. Do Slashdot readers know of any mechanical implementations of a truly Universal Turing Machine? (Danny Hillis' famous tinkertoy tic-tac-toe machine has neither infinite tape nor programmability, and is thus yet another FSM. It shouldn't be hard to elaborate the Austrian model train FSM to use a series of cars carrying movable magnets to represent Turing's tape cells writable with different symbols, and thus become a true TM or even UTM."

12 of 198 comments (clear)

  1. Too much time by strider44 · · Score: 5, Funny

    I just wasted about half a day compiling and recompiling my linux kernel to get it "just right".

    But still, I feel even I have the authority to say that some people just have too much time.

  2. Re:Just state machine? by Welpa · · Score: 3, Funny

    Yep, this is a truly embarassing story. Just goes to show that if you use enough technical jargon, you can fool a Slashdot editor into accepting a troll.

  3. Re:Just state machine? by KontinMonet · · Score: 4, Funny

    Microsoft patented a process for a 'limited resource computing device'. Presumably because they are aware of an unlimited resource computing device somewhere. Why don't you contact them?

    --
    Did he inhale?
  4. Mine was derailed... by Eternal+Vigilance · · Score: 5, Funny

    Would a UTM Railroad be a train of thought?

  5. Re:Finite State Machines? Don't knock-em by DisprinDirect · · Score: 3, Funny

    Is this not a Choo-Chooring machine?

  6. True mechanical implementations? by kinnell · · Score: 4, Funny
    Do Slashdot readers know of any mechanical implementations of a truly Universal Turing Machine?

    Given the requirement for an infinitely long tape, I suspect the answer to this question might be no.

    --
    If I seem short sighted, it is because I stand on the shoulders of midgets
  7. Awake for 29 hours, what do I see..... by Eatmorecake · · Score: 3, Funny

    I'm currently at work, graveyard, and this thing just blew my mind. Someone said this thing is terribly slow, (I doubt they meant it as an insult) but if you wanted to solve that problem you could make a three dimentional roller coaster version. That would be MUCH faster.

    --
    Don't you mean.. BIZZARO! ..Signature?
  8. I'm English . . . . by Tetsugaku-San · · Score: 5, Funny

    I bet they still don't run on time.

  9. Old news by Timesprout · · Score: 3, Funny

    Thomas the tank engine has been solving problems for ages now, and in multi task more he keeps the kids amused while he does it.

    --
    Do not try to read the dupe, thats impossible. Instead, only try to realize the truth
    What truth?
    There is no dupe
  10. Sure... by famebait · · Score: 3, Funny

    Do Slashdot readers know of any mechanical implementations of a truly Universal Turing Machine?

    No, but I have an infinite tape lying around in my shed, so if you know how to do the logic stuff, we can team up.

    --
    sudo ergo sum
  11. Thank God for model trains by Inkieminstrel · · Score: 4, Funny

    If they didn't have the model train, they wouldn't have gotten the idea for the big trains

  12. Forget the computer thingy... by Reignking · · Score: 4, Funny

    This layout is horrible! Get some trees in there! Some buildings? This guy made up the computer idea to hide the fact that he couldn't use plaster-of-Paris.

    --
    One man's Funny is another man's Offtopic.