We are a commune of inquiring, skeptical, politically centrist, capitalist, anglophile, traditionalist New England Yankee humans, humanoids, and animals with many interests beyond and above politics. Each of us has had a high-school education (or GED), but all had ADD so didn't pay attention very well, especially the dogs. Each one of us does "try my best to be just like I am," and none of us enjoys working for others, including for Maggie, from whom we receive neither a nickel nor a dime. Freedom from nags, cranks, government, do-gooders, control-freaks and idiots is all that we ask for.
Our Recent Essays Behind the Front Page
Wednesday, November 26. 2008
Pilgrims as Nazis? I thought immigration was a good thing.
Why the dimples on golf balls?
A new edition of Thornton Burgess' animal stories. Classics, for sure.
First-ever online spending decline
Viking beavers arrive in England en route to Scotland. Cool.
Does Europe really believe in International Law? Only when it suits them
The Western $ that flows into Gaza. Chesler. What is it buying?
The myth of Obama's small donors.
The people of Iceland mad at their government
Just the notion that a government can "fix" an economy is ridiculous. Or "fix" anything else, really. That sort of thinking raises dangerous and insidious expectations.
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YIKES! Are you suggesting that some significant portion of your readers don't know "why the dimples"? How frightening.
Well, if y'all are gonna know about the dimples all y'all will also need to know about Bernoulli's Principle
as well as the closely related Magnus Effect
There just is no point continuing on as a sports enthusiast of any sort (or even a basic life form for that matter) without at least a familiarity with why balls do what they do.
"There just is no point continuing on as a sports enthusiast of any sort (or even a basic life form for that matter) without at least a familiarity with why balls do what they do."
I've used that as a pick-up line on many occassions.
At the bar:
Jephnol: Hi! Yer perty. My balls do what they do because they do.
Miss Fanny: Hi! Do they make your putter flutter?
Jephnol: Why yes. Shall we go for a hole in one?
Miss Fanny: I have a 6 handicap. Will your wood go past the part other balls went?
Wicked Jephnol ... I think I would have been charmed by your originality, if I remember correctly ...
Bernoulli is a bogus explanation; also for airplanes.
The air along a streamline has lower pressure as it goes faster because it has run down a pressure gradient to get there. The pressure change causes the air speed, not vice versa.
The trick is to get a pressure change; and that comes from the Navier Stokes equations, which are pretty impossible to solve in general. The flow does what the flow does, is what an explanation comes to.
Airplanes fly by throwing air downwards. The wing shape happens to be pretty efficient at it, meaning that it throws the air best without introducing much forward drag in the process. Why that particular shape has no simple answer. It just does.
Bernoulli, in particular, doesn't explain it. For Bernoulli to apply, you have to have the streamlines first, and those could be anything; you have to consult the Navier Stokes equations.
Incidentally, you can't have hexagonal dimples. At least 12 of them must be pentagons.
Icosahedral symmetry, if they would only use it, would have only those 12, and has the added advantage that it has exactly equal moments of inertia about every axis.
I read in Joseph Campbell that the (I think it was) Wilson 432 was the best of all golf balls, in his day. Claiming the number of dimbles, 432, was related to the time of a respiration of Brahma, 432 whatever millions or tens of millions of years. This made perfect sense when I read it. And still does, in a way. But I'm not a golfer.
When it comes to sports and balls, we need to take into account the differences between the actions of spinning spheres traveling through fluids vs. the actions of a semi-static shape (such as a wing) traveling through fluids.
Another matter which does not seem to be addressed very well is hollow vs. sold spheres spinning their way through a fluid. And few sports balls are true solids but not all are hollow, so the actions of balls are not nearly as neatly described as that of wings.
And how do boundary layers come into play?
And then there is the matter of the little trailing edge vortices that help 'splain the "impossible" flight of bumblebees and hummingbirds and suchlike. I have this suspicion that there is some aspect of this in play with raised-seam, spinning balls such as softballs and baseballs.
If and when such a thing as a spinning baseball (or, especially the fastpitch version of a softball) can ever be filmed under the proper conditions we'll see the formation and breakdown of boundary layer and/or vortices along seams.
Which is all to say that I don't believe the comparison/analogy of spinning sphere (golfball or whatever) with airplane wings is particularly apt.
Saw a DVD last night, just released on Netflix, called "Blocking The Path To 9/11". Have any Maggie's Farmers seen it? Quite an eye opening example of government suppression of free speech and free press. I hope to see a post on Maggie's Farm soon to spread the word on this very convincing documentary. The efforts to prevent ABC from airing the docudrama "The Path To 9/11" have been relentless. Must be they have hit on the truth but the MSM seems to care not a whit, in fact, by it's silence is also suppressing the truth.
All lift comes from throwing air downwards. You can't bypass Newton.
Don't try to sell that to the Wonder Bra people or the Beverly Hills cosmetic plastic surgeons. 34 DD my favorite look on women under 30. Over 30 women are throwing down too much air and need to be avoided.
And when I'm gardening and shoveling dirt it sure does seem like there ain't much air help'n out other than my huff'n and puff'n.
If a quarterback spikes the ball does he drive air into the ground?
And when I do my workout if I do 3 sets of bench presses with 225 pounds how much air have I thrown down?
Ah... but those women over thirty throw experienced air... scented and charmed with knowledge and flair. No fountain of youth but surety of self they offer. If one but dare.
You're not over thirty, Meta, surely. So perhaps, in a few years, after a little seasoning my dear.
HABU !!! You can come press me with one leg. It will work out perfect.