Now, that gives me pause! I'm pretty confident of my understanding of a bicycle. The author claims that people challenged to make a sketch of its workings do things like omit the chain, or connect the chain to both wheels, or draw the pedals outside the chain, but I don't believe I'd make any of those mistakes. On the other hand, if zipper technology were erased tomorrow, the world would be using buttons and hooks for a long time if they were relying on me to re-invent that mainstay of modern fashion. I know a flush toilet has something to do with siphon power, but that's about where I quit. Years of dusting the perfectly visible workings of the hammers in my piano have left me a bit vague about how all the levers fit together, though I do understand generally that the key tilts on a lever and that eventually translates that motion to a final hinged piece that strikes a string. All I really know about speedometers is that they know what fraction of a mile represents one revolution of my tire; years ago I was warned that putting the wrong size of tire on your car will make your speedometer mislead you about your speed. Helicopters and cylinder locks might as well be black magic.
So perhaps some education is in order, beginning with the onomatopoetic zzzzzzzipper.
The basic idea is a row of interlocking teeth that fit tight when in a straight line but loosely when bent into an arc. If the row is in a spiral shape, it generally is made of polyester, while "ladder-type" arrangements typically are made of metal. According to Wikipedia, "A special type of metal zipper is made from pre-formed wire, usually brass but sometimes other metals too. Only a few companies in the world have the technology." This is the sort of thing that sets one's conspiracy-detectors buzzing, but a helpful Forbes article explains how one Japanese firm came to dominate the zipper business by the early years of this century, including a charming anecdote about growing pains as an Asian company attempts to expand overseas:
Yoshida told the employees he sent abroad to melt into the local population as much as possible. In one incident an employee sent to Holland spent months studying Dutch so that he could make an opening day speech to his employees in their own language. After his speech the workers are reported to have said, “Wow, Japanese sure sounds a lot like Dutch.”Of course, no sooner had Japanese entrepreneurs sewed up the zipper market than China began to give them a run for their money.
Here are some do-it-yourself repair guides for a broken zipper, which should be easy to complete with our newfound understanding of the mysterious mechanism.
DNA molecules operate very much like a zipper. In fact, all enzymes employ the trick of opening up a clasp so that an interlocking shape can be inserted or removed before the clasp springs back.
16 comments:
Basic gadgets? Really? What planet is this author from? A helicopter is not a basic gadget. Bicycle? Yes. Zipper? Kinda sorta. Piano key? Yeah, pretty much, but the entirety of the piano makes this seem difficult. Car speedometer is fairly easy, but falls into the same category as the piano. Cylinder lock? Really not that simple a gadget when you take one apart. (And I have) A flush toilet really is a simple gadget that uses the venturi effect, but the vast majority of the population has never lifted the lid of their tank, so they have no clue as to what the inner works even look like.
The book sounds like it has a good working premise, but instances such as the aformentioned *basic gadgets* tend to make me question everything put forth afterward.
The book didn't call them "basic"--that was my error in trying to get across the idea that we assume we have a basic understanding of something fairly familiar, until we try to put into words exactly what makes it tick. What we usually have, at best, is an understanding of how to operate it. (In the case of the helicopter, of course, most of us don't have that, either.)
The book doesn't claim that these are obvious gadgets--though none of them is in pure-genius territory--only that people tend to overestimate the depth of their understanding. Statistically, you can get many more people to claim confidently that they have a basic understanding of one of these mechanisms than can really back up the claim; it's a common cognitive illusion. Clearly there's no shame in not knowing how they work in enough detail to rebuild the factory or optimize the mechanism, but it's interesting that our brains are so constituted as to exaggerate how much we know.
I have an adequate understanding of machines that I have to repair on a regular basis. That doesn't mean I could build one from scratch -- there's a lot of precision in a bicycle, say, even one without gears -- but I have to understand the functional principles in order to effect the repair.
So, the real question is: "How often do you have to repair a flush toilet?" Well, sadly, it comes up more often than I'd like. Likewise chainsaws, motorcycles, bicycles, my truck....
Zippers? Not so much.
When I need an upgraded PC, I assemble one from its constituent parts, and install the relevant software.
This lets me do board-level maintenance, but I have no hope of understanding how any of that hardware works, or how to make the chips and "wiring" from the original sand and metal ores. My software maintenance consists of reinstalling.
I get some of this stuff from the other end, too: I understand the Carnot and Stirling Cycles quite well, but I have no hope of building an engine from those; I can only recognize whether a piece of hardware in front of me is likely to function that way.
After a certain point, our technology takes most of us beyond an ability to repair, when rebuilding is what's needed.
Basic gadgets? Those are levers, screws, inclined planes, etc. Those I can work with from scratch.
Eric Hines
Confidence is the only trick through which you can gain the power to fight back for your rights.
Thanks
Bruce Hammerson
Hammer Bits
"So, the real question is: 'How often do you have to repair a flush toilet?'"
Well, but not the question raised by the book. The real question is, why is it so easy for us to mix up two categories: "How familiar am I with the method of using this common object" and "How detailed a knowledge do I have of how it works on the inside?" If it's an object you've ever tried to build or repair, you probably have a very accurate assessment of your state of understanding (and that may be so whether your state of understanding is fairly low or fairly high). If it's one that you use all the time but have never taken apart, we might guess that your attitude is one of "I know how to use it, but not exactly how it works," which is to say you have a low understanding of how it works but a very accurate assessment of your level of understanding. But the interesting thing is that statistics show that most people let their familiarity with the gadget's everyday operation distort their assessment of how well they understand how it ticks.
It's not about whether we do or don't understand any particular gadget. Having cleaned and repaired bicycles, I do have a pretty good idea how they work, and my assessment of my own level of knowledge is probably pretty accurate. In the case of a couple of the other six gadgets, I knew right off the bat that I had almost no detailed knowledge of how they worked, which also may have been pretty accurate. But there was a category in the middle where my first instinct was to think I had a pretty good idea, but I found on closer examination that my confidence was an illusion based on my familiarity with the object and the ease of its everyday use.
I guess this is where my score on your recent bubble test shows me to be an outlier. I have fixed toilets. I've also fixed zippers, locks of many assorted styles from tumbler to cylinder to old-fashioned bolt-style that required a skeleton key, a piano (small one for the VES but it still worked on the same principle), a speedometer - whether for a bike or a car, it, too, still works on the same basic principle. The only thing I haven't played with is a helicopter. Although, I understand the basic design enough that I could draw a fairly decent picture of the gears, shafts and blades along with the internal combustion engine (which I have fixed on my own vehicles more times than I care to count).
One small quibble, though. To not put the helicopter in the "Genius" category is just plain silly at best. Remember it was DaVinci who first thought of it...just not in the motorized sense that we have today.
0>;~}
Oh, to think it up in the first place! Clearly genius. But to get a basic understanding of its physics once someone else works it out is not genius territory.
Again, though, it's not so much about whether we do (or should) know how it works as whether we're likely to mistake the depth of our own understanding, whatever that depth may happen to be. As I look up each of these gadgets, I'm continually surprised by some of the basic misconceptions I held about how they work, though I use almost all of them quite often. We just don't seem to be wired to distinguish carefully between knowing how to operate something and knowing how to design or build it. We can learn how to design or build it, of course, but can we learn how to assess accurately how much we already know, and overcome illusory intuitions of competence based on mere familiarity with operation?
Again, as I said, I'm the outlier. I don't overestimate my knowledge of how something works. I also don't underestimate it. My Pop was the type of man who believed in fixing it before throwing it away and buying new. So I had the luxury of watching, then helping, him tear apart pretty much anything and everything conceivable within the realm of a household and garage. (Later to include a grade school when he retired from the AF and took a janitorial job to keep his hands busy.) Our biggest challenge, of course, was putting it back together without having left over parts. And it was always a bit of prideful joy when parts were left over and the darn thing still worked....for a short while anyway. Then we learned what those left over pieces were all about, of course.
heh
0>;~}
I'd expect our self-assessment to be most accurate concerning a gadget we'd pulled apart and tried to repair. The question is, can we be that accurate about one we haven't done that with?
That's why I say I don't overestimate my confidence level. I've taken apart too many things of varying degrees of difficulty to know when something is too big for me. Course, too many times of having left over parts will bring even the most smarmy of do-it-yerselfers down a peg or three.
0>;~}
Always so discouraging. "What do you suppose was the function of that funny-looking little piece, there?"
I'd expect our self-assessment to be most accurate concerning a gadget we'd pulled apart and tried to repair. The question is, can we be that accurate about one we haven't done that with?"
That depends on how much of the workings you can see. If you were able to look at a Bell 47 helicopter- and I mean really look at it, in person- you could figure out how it worked for the most part- it was all there to see- a modern chopper- that would be tougher- much of it is covered up and parts are integrated into other parts, etc.
I was always one of those people who really looks at things, and loves to try assembling or fixing things, and also looking at cutaways and diagrams and blueprints to understand the guts of things, so all the items listed, I'd have a pretty good grasp of and could diagram out how they work to someone.
Bicycles are easier than you think- there are a few things that aren't obvious up front, like steering angles, rake and trail, but the rest- drive mechanism, structure- are about as basic as it gets. The architecture school I went to had a few objectmaking classes back then where students built bicycles/pedomotive vehicles of one sort or another- mostly successfully! If those students could do it, I think most here could too if they had to.
See, I know I'm capable of understanding them all. It's just interesting that, before I actually go do the work of examining them and understanding them in detail, I already have something of an illusion of understanding them. The illusion crumbles when I try to put my understanding into words and diagrams! That's when I find out I really had just a general notion.
The bicycle was an exception: I was sure I understood the drive train and the hand-brakes and maybe even the ten-speed gear-shift. Now, when it comes to the optimal arrangement of the frame, and how best to cut down on weight without losing strength, or the most stable steering arrangement, . . . .
Do I understand roughly what's going on with a helicopter? I suppose so: each blade on the main rotor probably has a leading edge that's a lot like a fixed wing on a conventional aircraft, providing lift when it spins and lateral thrust when it tilts. The tail rotor must do something to counteract the angular momentum imparted to the helicopter by the main rotor. But then, my understanding of why wings of certain shapes provide lift is kind of vague. I think I read lately that people are beginning to doubt whether the traditional explanation was quite right, anyway, even I had fully internalized the traditional explanation, which I have not.
Always so discouraging. "What do you suppose was the function of that funny-looking little piece, there?"
Tell me about it. Not too long ago, MH and I had that very conversation regarding our lawnmower that wasn't running *right*.
heh
Of course, what's worse, is knowing what the part is, but not being able to figure out where it came from.
*sigh*
0>;~}
I hear you Tex- we don't know the issues, really, till we dive in and get our hands dirty, so to speak. I think this gets back to Grim's posts referring to the 'known unknown' vs. the 'unknown unknown'.
Lift isn't that complicated, and I'm pretty sure the traditional explanation (assuming it's lift and not mechanical lift, which is deflection off the bottom) still holds. Imagine two air molocules approaching the leading edge of the wing, next to each other, and lined up so that one will be above, and one below the dividing line of air going over or under the leading edge. Now imagine that as they each go their separate way, the one on going under only has to move a little to go under and past the wing (as the bottom of the wing is close to flat) and the one going over has to go further around because the top of the wing is more rounded. Since nature abhors a vacuum, they need to come back together at the trailing edge of the wing- so that means the molocule going over has to go faster to meet up with the one going under who goes at about the speed he was going in the first place. If the one going over the top (and all like him) are moving faster, Bernoulli tells us that there will be a reduction of pressure as a result, relative to the guys below. That pressure differential results in a force upward on the wing (call it push from below or pull from above or both as you like). Voila- Lift!
Okay, so being able to run through that explanation, I feel pretty confident that I do understand how airplanes work :o)
Post a Comment