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Monday, October 11, 2010

Better Science: Lift

It all started on Saturday when I saw xkcd's Airfoil comic. Suddenly, I was confronted with the reality that I did not know how planes produce lift. Feeling like an ignorant chap, I googled "how do planes fly"...

The premise of these next few posts is that there are some poor/bad explanations out there in popular scientific understanding--or lack thereof. The goal, then, is to get us to think a little better about some commonly held ideas. Please keep in mind: I am not a scientist. I don't play one on TV or science DVDs. I'm a guy who loves to learn stuff. These are my observations based on my understanding as of posting. As I learn, I hope my views will be refined ...which is the point of discussing better science. <smile>

Years ago I produced my first educational DVD. In it, we touched on flight. We demonstrated how blowing over the top of a hanging strip of paper causes it to rise and flutter. Faster air moving over the top causes the pressure above to drop. This makes the higher pressure air below push up. And this activity is closely tied to the plane explanation on the same page of your science text:


Science Activities, Vol. 2

This basic--kindergarten level--premise was never challenged, not even in high school physics. Wings work by producing a pseudo-vacuum which is enough to keep planes aloft.

Works for me.

And then I read a "Level 3" Description of Lift. My continuous nodding and occasional "ah-ha!" of understanding was frequently displaced by confusion. I felt rather lost.

I should have read the How Stuff Works article on planes first. Very fascinating stuff--which, again, quickly moved outside my immediate capacity to grasp.

Did you know this stuff about airfoils, wings and lift? Or were you only taught the Bernoulli principle? What areas of science have you learned about which are not exactly the way you were taught them?

 ~Luke Holzmann
Filmmaker, Writer, Empty Nester

4 comments:

sumpteretc said...

I guess I never really cared why airplanes fly. I tried to go to your links, but I was daunted just looking at the pages. I'll just stick to reading the comics.

Luke said...

<smile> Basically, life is not exactly the air flowing over the wing. Instead, it's the air flowing over the wing which is directed down, which produces lift with the air forced down under the wing. All that air going down produces a force in the opposite direction, pushing the plane up.

...at least, I think that's what all that stuff meant <smile>.

~Luke

desilou freebush said...

interesting! i suppose i've always taken the fact that planes fly for granted . thanks for sharing your learning adventure!

... ehhh, also, i wanted to share my all-time favorite xkcd cartoon with you: "Velociraptors" http://xkcd.com/87/

Luke said...

Desilou, I hadn't seen that one yet. Hilarious! <smile>

~Luke


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