Jon Hardesty
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Thanks Mandrin. Your work is appreciated.
Miura - parametric acceleration
- Thread starter mandrin
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Consider Parametric Acceleration iV
http://www.angelfire.com/realm/moetown/mandrin/golf/Swinging__left.html
Where in the mandrin of la mancha states this lie:
Parametric acceleration occurs for clubhead pull along the centripetal force vector.
Which just goes to show us he still doesn't understand that which he writes about. The irony is he had it correct in another of those CFD's in that only an off axis (i.e. non-normal non-centripetal) component of force can increase tangential velocity. One day those "way behind the curve" devotees of the mandrin will come to realize so-called parametric acceleration is occuring for the duration of the final two stages of the downswing of better strikers not just prior to impact. Undoubtedly that will be sold as some lofty new revelation as well. The beat goes on...
PS
Seems Bernt burried the hatchet which is too bad because he mades some good points. I submit he knows his physics far better than the mandrin.
http://www.angelfire.com/realm/moetown/mandrin/golf/Swinging__left.html
Where in the mandrin of la mancha states this lie:
Parametric acceleration occurs for clubhead pull along the centripetal force vector.
Which just goes to show us he still doesn't understand that which he writes about. The irony is he had it correct in another of those CFD's in that only an off axis (i.e. non-normal non-centripetal) component of force can increase tangential velocity. One day those "way behind the curve" devotees of the mandrin will come to realize so-called parametric acceleration is occuring for the duration of the final two stages of the downswing of better strikers not just prior to impact. Undoubtedly that will be sold as some lofty new revelation as well. The beat goes on...
PS
Seems Bernt burried the hatchet which is too bad because he mades some good points. I submit he knows his physics far better than the mandrin.
Michael Finney
New
nmgolfer, broncobilly - whoever you are.....miura cleary states that the acceleration comes from the inward pull and the upward pull - with the inward pull being a greater component.....the line of centripetal pull in this case is off-axis with regard to the two component vectors, no?
What makes so-called parametric acceleration happen is the velocity vector of the club head (cg of the club actually but just assume all mass is in the ch) not being normal to the direction of the force from the shaft. Were it possible to decrease the length of the shaft during the swing (by supplying excess centripetal force) this would accomplish the same thing as moving the center of rotation. You're making the velocity vector of the club mass not line up with the path it must follow as dictated by the kinematics and that slight difference creates a force in the tangential direction which can accelerate the ch.
To wrap your mind around Parametric acceleration do this. Fetch a hex nut, a length of string a nail and a hammer from the garage. Pound the nail in just a bit on the edge of a wooden table so you can drape the string tied to the hex nut over it. Swing it like a simple pendulum... Now add some PA. as the nut reaches the nadir of its arc, slightly tug on the string. Play that excess out as it nears the top and begins to reverse direction. Repeat. After a few cycles you should notice the amplitude of the pendulum oscillation is increasing. That is parametric acceleration!
BTW it works the other way as well. Let some string out near the nadir and pull in near the top and the pendulum amplitude will decrease. THis is where this comes from... vibration damping research.
The difference is in golf we're applying parametric acceleration for the duration of the 2 final stages of the downswing not just the last instant. This in effect is what the constricting hand path is achieving for us.
To wrap your mind around Parametric acceleration do this. Fetch a hex nut, a length of string a nail and a hammer from the garage. Pound the nail in just a bit on the edge of a wooden table so you can drape the string tied to the hex nut over it. Swing it like a simple pendulum... Now add some PA. as the nut reaches the nadir of its arc, slightly tug on the string. Play that excess out as it nears the top and begins to reverse direction. Repeat. After a few cycles you should notice the amplitude of the pendulum oscillation is increasing. That is parametric acceleration!
BTW it works the other way as well. Let some string out near the nadir and pull in near the top and the pendulum amplitude will decrease. THis is where this comes from... vibration damping research.
The difference is in golf we're applying parametric acceleration for the duration of the 2 final stages of the downswing not just the last instant. This in effect is what the constricting hand path is achieving for us.
Dariusz J.
New member
It is greater because of impact biokinetics. Other words, lead side center travels more horizontally than vertically.
I think the so-called "parametric acceleration" is just simple physics (simple to understand, more difficult to use correct numbers and equations) and people like to demonize such subjects because of that.
Cheers
Michael Finney
New
don't know where mandrin said it was restricted to the last instant or miura for that matter.......or nesbit or mackenzie.....
birly-shirly
New
sorry for the threadjack - but is this how a swing in a children's playpark gains momentum - by pulling on the chains or ropes and shortening the radius?
always wondered about the physics of that - and forums discussing the golf swing are far more common than the other sort...
Really? Michael all talk of "going normal" has been directed at the moments just before impact. Furthermore its in the title of Muria's paper:
Parametric acceleration – the effect of inward pull of the golf club at impact stage
K. Miura
Michael did you even attempt to read the research?
Parametric acceleration – the effect of inward pull of the golf club at impact stage
K. Miura
Michael did you even attempt to read the research?
S
SteveT
Guest
Interesting to watch all you techno-peasants trying to figure out all the forces, centripetal, parametric, linear, whatever... that affect the arms, hands and golfclub... when the answers lie in the analysis of the entire system... from the ground reaction forces to the toe of the club, and even the top of the head. Your problems reside in the reality that you can't analyze the entire golfswing system, trying in futility to isolate the easiest element... the arms, hands and club... as if that will give you all the answers you need to solve your golfswing woes.
Sorry, boys.... trying to patch up your homemade golfswings with "scientific" golf tips just won't work ... and to your credit at least you are questioning the validity of what you think you know about the golfswing. It's like watching slow motion Physics 101 ... and you guys are still in grade school thinking you can avoid the mass of knowledge you must possess to really comprehend the scientific studies. It ain't gonna happen fellas, and all you can hope for is learning from Brian's 1.68 filtering the bits of science into something teachable and usable.
But keep on banging against the science wall, maybe something will crack open .... and ... I'm impressed with the directions some of your questions are leading. Wonder if somebody, like mandrin, will relieve you from your scientific angst. Ah, the human spirit trying to emerge from it's dark ignorance ... keep banging, boys .... I'm watching.
Sorry, boys.... trying to patch up your homemade golfswings with "scientific" golf tips just won't work ... and to your credit at least you are questioning the validity of what you think you know about the golfswing. It's like watching slow motion Physics 101 ... and you guys are still in grade school thinking you can avoid the mass of knowledge you must possess to really comprehend the scientific studies. It ain't gonna happen fellas, and all you can hope for is learning from Brian's 1.68 filtering the bits of science into something teachable and usable.
But keep on banging against the science wall, maybe something will crack open .... and ... I'm impressed with the directions some of your questions are leading. Wonder if somebody, like mandrin, will relieve you from your scientific angst. Ah, the human spirit trying to emerge from it's dark ignorance ... keep banging, boys .... I'm watching.
Interesting to watch all you techno-peasants trying to figure out all the forces, centripetal, parametric, linear, whatever... that affect the arms, hands and golfclub... when the answers lie in the analysis of the entire system... from the ground reaction forces to the toe of the club, and even the top of the head. Your problems reside in the reality that you can't analyze the entire golfswing system, trying in futility to isolate the easiest element... the arms, hands and club... as if that will give you all the answers you need to solve your golfswing woes.
Sorry, boys.... trying to patch up your homemade golfswings with "scientific" golf tips just won't work ... and to your credit at least you are questioning the validity of what you think you know about the golfswing. It's like watching slow motion Physics 101 ... and you guys are still in grade school thinking you can avoid the mass of knowledge you must possess to really comprehend the scientific studies. It ain't gonna happen fellas, and all you can hope for is learning from Brian's 1.68 filtering the bits of science into something teachable and usable.
But keep on banging against the science wall, maybe something will crack open .... and ... I'm impressed with the directions some of your questions are leading. Wonder if somebody, like mandrin, will relieve you from your scientific angst. Ah, the human spirit trying to emerge from it's dark ignorance ... keep banging, boys .... I'm watching.
Steve, We're all wrestling with the problem of 'going normal,' while you're fighting with just being normal...No wonder you're so pent-up..
In all seriousness, It is great to have you back. A couple of your earlier posts worried me: I thought you were going soft on us, but, as they say, "Form is temporary...class is permanent"
S
SteveT
Guest
Hey, I know I have more brains than talent.. whereas y'all don't. And trying to incorporate a magic scientific swing tip into your magnificent bodies can be fatal. Science kills, or it can drive you insane before you off yerself.
Ignorance is bliss .... tell us more besides chirping. Btw... where is birdie_man ... on a golf sabbatical with some woman???... smart man!!!
ZAP
New
Hey, I know I have more brains than talent.. whereas y'all don't. And trying to incorporate a magic scientific swing tip into your magnificent bodies can be fatal. Science kills, or it can drive you insane before you off yerself.
Ignorance is bliss .... tell us more besides chirping. Btw... where is birdie_man ... on a golf sabbatical with some woman???... smart man!!!
I edited the chirp post because I decided is was not appropriate and added nothing to the conversation. I am simply here to learn about golf and get better if I can. As they say the rest is just show biz. There are enough people to argue with in the real world.
What really bothers me is that I never thought about some of this stuff on my own. I guess I was so concerned with playing golf that I never thought much about the different ways to swing the club.
Hey, I know I have more brains than talent..
From what I can gather, your I.Q need only clamber into double-digits to make that a truism...
Like I said, good to have you back....
S
SteveT
Guest
Best not to struggle endlessly trying to conquer the golfswing... it will derange you!!! Read up on obsessive-compulsive disorder on wikipedia... and then look in the mirror ... I did.
From what I can gather, your I.Q need only clamber into double-digits to make that a truism...
Like I said, good to have you back....
Hey, Big O... my Impact Quotient is maxed out at 1.5, thank you .... and I have a headache from carrying all those extra brain cells with me walking the golf course... where I have to dumb down to enjoy myself... and break 100 too ...
ZAP
New
Ask anyone who knows me. I am probably the opposite of OCD .....whatever that is. Do you have to wear a neck brace after a while when your neck gets tired from holding up all those extra brain cells? It must be very difficult being so much smarter than everyone else. I really feel for you. Thanks for sharing just a little bit of your greatness with us. Please do not overwhelm us with too many big words. They give me a headache.
S
SteveT
Guest
I was only worried about your state-of-mind trying to slay the scientific dragon by running up to it and swinging your golfclub at it ... that's all.....
Michael Finney
New
Gimme, you giant douche bag, the effect of inward pull of the golf club at impact stage is what Miura wrote about......did he say it didn't occur at other stages?.....
Nesbit repeatedly says that the force vector at the hands is pointed inside the path of the hands for a good portion of the downswing......it only goes normal to the club head trajectory near impact.....you could make a case that sasaho Mackenzie's description of the hand path pulling the COG of the club into line the entire downswing is a form of parametric acceleration.....are the hands not "pulling" in a direction? Is the club head not speeding up?
You can make a great case that the ENTIRE downswing is like a kid trying to make himself swing higher......parametric acceleration from the first move down........the hammer thrower does this by protracting and retracting the shoulders during every turn...not just at the impact stage....continue with your douchebaggery
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