pivot question

[mandrin]

You know a "man(drin) of science" is full of it (caca) when he doesn't even attempt to apply his pseudo-scientific illogical quackery in the defense of his false conclusions. You know you're dealing with a swindler, a fake, a phony when the man(drin) fails to present one iota of verifiable evidence in support of his defenseless conclusions. Such a scoundrel, such a con-man, such charlatan immediately resorts to using the logical falacy his meek pathetic little self finds most comforting.

nmgolfer,

For someone claiming to having acquired a more zen-like attitude, you are surprisingly easy getting excited and starting becoming uncivilized . Please remember, it is just golf, an agreeable pastime. Try to take it easy my friend, otherwise blood pressure gets up high , etc., etc..

To bring you more up to par with the mathematical reality of a golf swing - being a ensemble of masses, linked together, driven by torques at the joints - I like to suggest some reading so that you can learn hopefully more about the appropriate mechanics and mathematics.

As a starter I like to suggest that you begin with -

-1- Dynamics of Mechanical Systems
Harold Josephs, Ronald Huston

-2- Fundamentals of Multibody Dynamics - Theory and Applications
Farid Amirouche

 

[nmgolfer]

Oh but you're wrong once great one... I am zen. Tell us oh great poser who arrogantly calls himself the mandrin ... what's different about those texts? Did they get it wrong like you do? That would explain their scarcity in academia. Again, defend yourself, your once hallowed reputation... you're ridiculous theory... and do it like a scientist not a wimp.

 

[tongzilla]

pls dont lock this thread. I want to see how the debate between the geeks turns out.

 

[Jared Willerson]

pls dont lock this thread. I want to see how the debate between the geeks turns out.

Me too.

 

[mandrin]

caca

Oh but you're wrong once great one... I am zen. Tell us oh great poser who arrogantly calls himself the mandrin ... what's different about those texts? Did they get it wrong like you do? That would explain their scarcity in academia. Again, defend yourself, your once hallowed reputation... you're ridiculous theory... and do it like a scientist not a wimp.

Mr caca,

I am not surprised you don’t recognize the references, taking them to refer to obscure unimportant papers when they actually refer to two serious well known excellent beefy reference books, written by eminent scientists /professors, reflecting and representing many years of scientific research work. It shows clearly the shallowness of your background.

It hurts me to see eminent scientists being so light heartedly being down played and belittled by you, having this peculiar obsession for the brown stuff. Why don’t you consult Freud on this subject, you will perhaps learn why you have this queer obsession.

Since you are an expert on pipi caca, I think it is most appropriate to finish by stating that I am not interested wasting my time pissing into the wind.

 

[thefuture37]

another vote to end this thread

 

[jmessner]

Girly-man golfers?? NM...what the deu...

I finally found something I have in common with Tiger!

Vclubhead = Vhands + w*R

I must be missing something. The equation for a double pendulum (which is hugely simplifed for a golf swing) shows a more complex situation. Add to that the curvilinear path of central point (left shoulder) and and added torque from left shoulder and wrists....

Double Pendulum Motion

 

[nmgolfer]

I finally found something I have in common with Tiger!

An what prey tell would that be? Surely you're not insinuating Tiger is a girly-man...

I must be missing something. snip.......

You are. The only thing that matters is club head speed and club head speed is determined by that simple equation: Vch = Vhands + wXR . Double pendulums, while amusing to geeks and pseudoscientists, have nothing to do with the golf swing.

 

[jmessner]

An what prey tell would that be? Surely you're not insinuating Tiger is a girly-man...

As it turns out, you are making that insinuation....I was just making the point that his hands slow down as well. This was discussed in previous threads.

You are. The only thing that matters is club head speed and club head speed is determined by that simple equation: Vch = Vhands + wXR . Double pendulums, while amusing to geeks and pseudoscientists, have nothing to do with the golf swing.

I might buy that equation holds instantaneously, but the point I was making is that Vhands and w are not indepedent.

I'm guessing those Physics PhD's that have modeled the golf swing using a double pendulum should get their tution back. I think it's a useful simplification at some level, but I understand you think otherwise.

 

[nmgolfer]

I understand people have made that claim (tiger's hands slow)... I've never seen it proven. If he does, it simply means even he has room for improvement.

Vhands and w are independent although the magnitude w does depend on Delta Vhands i.e. hand acceleration). The equation I gave you is valid everywhere and anytime during the swing.

Pendulums are by def. gravity powered. The golf swing is not. (That problem that can be overcome). Pendulums have a fixed central pivot. Golf does not (Jorgenson, in trying to make a pendulum come close to matching a real golf swing, found he had to let the central pivot translate). Pendulums have fixed radii (circular paths). That is a problem that cannot be overcome.

As it turns out, you are making that insinuation....I was just making the point that his hands slow down as well. This was discussed in previous threads.

I might buy that equation holds instantaneously, but the point I was making is that Vhands and w are not indepedent.

I'm guessing those Physics PhD's that have modeled the golf swing using a double pendulum should get their tution back. I think it's a useful simplification at some level, but I understand you think otherwise.

 

[dbl]

For the case of a bullwhip, you could say Vtip=Vhands + Vrelativetohands but bigdeal. Such an equation does not imply that Vhands must always be increasing, or explain reality for when Vhands is zero or negative (as mentioned above in post 176)

Originally posted by NMGolfer
(translated)
Now you tell me... what do you think happens to Vtip when Vhands = 0 or is decreasing? That's right... Vtip decreases

 

[Bronco Billy]

Equations(Functions) Do Not Imply Anything. They Only Represent Cases of Reality...

For the case of a bullwhip, you could say Vtip=Vhands + Vrelativetohands but bigdeal. Such an equation does not imply that Vhands must always be increasing, or explain reality for when Vhands is zero or negative (as mentioned above in post 176)

.

 

[dbl]

BB, there we go, thanks for shooting down NMG's contribution in this thread.

 

[dashfan87]

You know, at this point... Im happy, because Im pretty sure, I can play better golf than these nerds.... Just saying.

 

[Bronco Billy]

The Only Thing I Shot Down was Your Assertion..... Have a Great Day......

BB, there we go, thanks for shooting down NMG's contribution in this thread.

.

 

[Bronco Billy]

I Wouldn't Be Too Sure of That......

You know, at this point... Im happy, because Im pretty sure, I can play better golf than these nerds.... Just saying.

.

 

[dashfan87]

then post up your swing, and your handicap.

 

[nmgolfer]

Golf Clubs and Golfers are not bull whips.

For the case of a bullwhip, you could say Vtip=Vhands + Vrelativetohands but bigdeal. Such an equation does not imply that Vhands must always be increasing, or explain reality for when Vhands is zero or negative (as mentioned above in post 176)

DBL, Remember when you misinterpreted Nesbit's graphs? You're doing the same thing with the bull whip. They're complex things involving wave propagation, conservation of momentum and energy. And they have nothing to do with golf: http://math.arizona.edu/~goriely/Papers/2002-PRL(whip).pdf

You are right about one thing though. That equation does not require hand velocity to be increasing. We've all seen golfer's who's hands do slow down.

http://www.newgolfswing.com/images/newgolfswing08_clip_image016.jpg
Some who slow their hand are even "good" golfers. However, that does not mean they optimize their effort and in turn club head speed.

 

[thefuture37]

gotta agree with dashfan. however true either of these arguments may be, I seriously doubt that they are: necessary to know in order to make a great golf swing/make anyone a better golfer/make it easier to teach a great swing etc... this thread is an argument of golf theory which has little basis in practical golf.

 

[nmgolfer]

It's like watching TV. I hate reality shows and dance competitions. I don't watch them. People who agree with Dashfan and thefuture37 should not read this thread. They're entitled to their opinion but they should go elsewhere and learn to live and let live.