Friday, December 3, 2010

Human reasoning

"The candle problem" is a classic experiment of insight put forth by Karl Duncker in 1945.

Each subject is given a candle, a box of tacks, and a book of matches and asked to attach the candle to a wooden wall.
If you were a subject in the test, how would YOU do it?

Tomorrow: the Duncker solution.

Relax Max's supplimental: Duncker's problem is fine for college students, but much too simple for the people who read my blog, sooo... can you do it without the matches?


  1. Yes, but it won't give out much light. I can think of several ways.

    Back in the days when I was toying with design as a career, our college tutor would set all manner of tests like this. I can't remember this one, but we'd be given a problem, and a big sheet of paper, and told to draw twenty solutions....

  2. I see the rush to give solutions has overwhelmed the comments page.

    I had chosen not to give my solution in order to see what others came up with, without influencing them. However, as there's no rush of answerers, I'll post mine now. Choice of method would alter depending upon whether you'd want to light the candle after attachment,if not, the easiest way of all would be a thumb-tack through the wick. You could make a dandy little shelf out of the book of matches thumbtacked to the wall, nicely diagonally braced...
    Or,just tack the tack-box itself to the wall.
    With a tack through the bottom to hold the candle. The box looks a bit flimsy though. Am I allowed to fold and alter to make a more rigid shelf?

  3. I think you are right. No one actually reads this blog any more. Even YOU don't read it if I don't twitch one or two of your brain cells. :)

    How about no box and no tacks? Well, I suppose the wick wouldn't stick to the wall very well on a drop of melted wax. But this is only theoretical, right?

    Maybe I would use a tack to scratch a little hole in the wall and then stuff the wick into it. :)

  4. How about using a tack to scrape most of the wax off both ends until you could tie the wick ends together and hang the candle on a tack stuck in the wall? Well, I suppose it wouldn't really be a candle anymore. :)

  5. You or I, being resourceful types of a self-sufficient nature, might jusy whip out a sharp pocketknife, and carve a candle-sized hole in the wooden wall.

  6. What's the box made of?

    I would attach the box to the wall with a tack or two and stick the candle on top.

  7. Wax is fine. Soften it before you put the pin through.

    You are so lacking in trust, you know.

  8. You want to attach a lightable candle to a combustible wall.

    Stephanie the Safety Engineer says "No," and tells you you can buy very effective LED lights (attached via velcro) at IKEA and Walmart. Great for perusing bookshelves looking for the right book, too.

    Besides attaching a consumable to a wall is silly unless you're never going to use it. Once it's gone, you'll have to unattach the unsightly stub and attach a new one. If it's just for show, you aren't going to want to use any of these items. They're ghastly.

  9. It will probably not surprise you to know that I drove my Engineering design class batty because every project I did began with what was wrong with what they wanted (and why it wouldn't work) and what they should have asked for instead. And then I'd give it to them.

    "Most" engineers I've come across cannot think outside the box or the formula, or ask themselves, "What the hell am I doing it this way for?" I'm (surprise!) an oddity.

  10. @Stephanie Barr - No one said the candle was lightable. Don't jump to conclusions in these things. They didn't have LED lights in 1945. Or Walmart.

    Wait. Is this the famous Stephanie sense of humor? :)

    (No, it would not surprise me.) :)

  11. Yeah, but in 1945, the wall was probably made of asbestos.

    You didn't ask in 1945.


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