Sunday, April 8, 2012

Sometimes, Things Take Care of Themselves

Off on another tangent, I want to open with something you've seen but may have never actually noticed or thought about.  For this concept, observe this photo of the well-known Piper Cherokee airplane:
Pilots may skip a few paragraphs and come back later, but I want to draw your attention to the angles the wings make with the horizontal.  Notice how they don't make a line parallel to the ground?  Do you know why? 

One of the things most people don't "get" about aircraft wings is that there is a small range of angles over which they provide lift, and a very small range for optimum performance.  A wing provides the most lift (vertical force to counter gravity) when it's parallel to the ground,  In addition, the angle of attack - the angle that wing makes in the front/back direction - is carefully controlled, and usually small.  Most airfoil designs provide increasing lift with angle and then suddenly stop lifting (called a "stall" - but has nothing to do with the engine) when the angle of attack is beyond about 30 degrees.  Ever notice that most airplanes land at a shallow angle, and take off at about 10-15 degrees? 

The reason the Cherokee's wings angle like this is that they make the plane easier to fly by providing an automatic, hands-off control system that corrects for minor errors in handling or wind differences.  If one wing were to get more lift than the other, due to minor variations in the controls, that wing will start to lift, rotating the plane around the line pointing at us in the photo.  That wing will pull up and the other roll down to a more horizontal position.  As this happens, though, the lifted wing will loose lift and the the one that became closer to horizontal will get more lift, returning both wings to the neutral orientation seen above. 

If you look at virtually all low wing aircraft from small single engine planes like this to commercial jets, the wings are angled to the fuselage in a similar way.  It acts like a feedback control system to return the plane to level flight. 

Modern small planes incorporate so many little things like this that many accidents happen because the pilot defeats the airplane and if they would simply take their hands off the controls, the plane would right itself and resume level flight.  I've heard dozens of stories of a pilot falling asleep or being incapacitated and the plane going on in level flight.  I'm sure I haven't heard them all.

So where am I going with this?  A free market economy has several of these built-in feedback system at work, the biggest being simply "supply and demand".  What's a house, a car, or a diamond worth?  Exactly what someone will agree to buy and sell it for.  And just like the student pilot that crashes their plane because he can't take his hands off the controls, our "leaders" keep messing with the supply of money, the interest rates, allowing or blocking foreclosures, and other things. 

If the Fed, the European Central Bank, the Bank of Japan and all the rest evaporated overnight, followed by the collapse of the global fiat monetary systems, it would be a horrific transient that would hurt like crazy, but in the big picture it would be like the airplane's wings.  The world's economies would eventually right themselves if the "powerful" would stop screwing with it.  


  1. Sadly, it is in the "screwing with it" that both politicians and Banksters can earn fortunes and gain power. Their real profit motive exists in the up and down versus the hands-off level flight.


    1. The other side of that same coin is the desire of certain elements - such as little Barry and his friends Richard Cloward and Frances Fox Piven - to actually wreck the economy in an attempt to force a turn to full government control (almost there now). So they don't mind those bankers and politicians getting rich. They will get some themselves, and accomplish their agenda at the same time.

      They've got the throttle fire-walled, the yoke pushed all the way forward, and are in a dive that will soon over-stress the airframe causing it to disintegrate and then crash, in SiG's example.

    2. The thing that's in the back of my mind is that if there really is the kind of revolution they seem to be calling for, the folks taking money now will get the usual treatment useful idiots get: the Kalashnikov to the back of the head. Even Fearless Leader is not immune to such treatment.

      A while back Borepatch had this link to a comic book treatment of a communist takeover of the US. One step is the assassination of the president and vice president. Tell me it doesn't look like that now.

  2. Never considered dihedral and the banking system in the same sentence!

    1. Neither has anyone else. It's just part of the service.

  3. And if you overreach the ability of your wings to provide lift by misusing the controls to point the nose too high and hence find your plane plummeting out of sky, how do you recover?

    Point the nose at the approaching ground until sufficient lift can be regained to rise again.

  4. I was discussing on Friday the concepts of entropy and equilibrium with a co-worker. Everything seeks a lowest energy (entropy) stable (equilibrium) state. Or in other words, everything will eventually settle down into something. The trick is creating feedback systems to manipulate that stable state. The idea is to set things up in such a way that negative (subtractive) feedback creates a self-limiting system that can then be let to run on its own with little to no outside input - your plane wing example is a perfect illustration of this concept.

    But try explaining negative feedback to a soft-science, 'math is hard' emotive thinker. Most immediately turn off at the word 'negative' and can't grok anything past that. At least that's been my experience. Guess that makes me a evil, rigid, negative person - what can you do?

    1. LA,

      What can you do? Don't drink the Kool-Aid and stop munching those Skittles.

      And stop being so tough on us "math is hard", emotive types. Just because I can't calculate how many kilotons are required per hundred thousand muslims doesn't mean I'm going to get all weepy when someone gets around to taking out Mecca and Medina.

      A Saudi prince once asked Gene Roddenberry why there were no muslims on Star Trek. "That's because it takes place in the future", he replied.

      Good to see you on-line again, buddy.

    2. LA,

      Re-reading my comment made me realize I should have included some smilies so that you would know I was being tongue-in-cheek. Just in case that wasn't clear. (Except for that thing about Mecca and Medina. It would be nice to be able to see the glow from orbit.)

    3. No problem Reg - I was smiling as I read it, especially the Gene Roddenberry part. Its good to have a little time again to resume participation in the blogosphere!

  5. Agreed! Everytime I mention Negative Feedback Loops in my blog, I hear crickets in the comments section. Properly engineered machines (and the political sphere can be considered a machine) need that. Positive feed back is dangerous and sadly, that is what we now have with an Entitled electorate.

  6. Shoot, I thought you were headed off into dihedral land and engineering compromises and whatnot.