Lag Pressure Talk

[mandrin]

I get the feeling that we're differing on terminology, and the specifics of that terminology.

As far as velocity and acceleration goes, they're not, in the most strict sense, directly related to change of direction. In short, speed is how fast something is going, whether it is moving away from its starting position or not. Velocity measures the rate tha something is moving away from its starting point. When you have a change in direction, then there are two separate velocities involved; the one before the change of direction, and the one after. Acceleration is the rate of change of a velocity, ie the rate that something is speeding up or slowing down. If you change directions, then you introduce a different vector. In reference to the clubhead during the swing, there's a vector that represents the velocity or acceleration of the backswing, then a separate vector to express the same for the downswing. So the change of direction, from a physics standpoint, marks the starting point from which you would measure the downswing acceleration of the clubhead. The definition of acceleration dosen't include the change of direction.

Bigwill,

Velocity and acceleration are vector quantities and hence defined by both magnitude and direction.

An object moving in a circular path with constant angular velocity has a constant tangential speed but is continually changing direction.

This change, only in the direction not in magnitude of the velocity vector, results in an acceleration of the object, normally to the circular path.

(FYI, Ringer is not referring to the transition at the top of the back swing but to a change in direction during the impact interval )

 

[Ringer]

Ringer, I wonder if your are inventing a new kind of dynamics. Let’s have a closer look and see if we can sort things out.

Not letting the angle open up till late in the down swing (sustaining the lag) will help obtaining a large clubhead velocity at impact.

During the about 0.7 inches that the ball and clubhead travel together for 0.0005 sec the clubhead loses a fair percentage its speed.

There is no rapid change of direction during the impact interval, only a very sudden and large deceleration of the clubhead.

Homer musta been smok'n when he wrote:

"Zero Deceleration is what would give maximum ball speed for any and all approach speeds. Speed and Prestress stiffen the Clubshaft for consistent resistance to Impact Deceleration."

And just how does one pre-stress the shaft and resist impact deceleration?

 

[Bigwill]

Bigwill,

Velocity and acceleration are vector quantities and hence defined by both magnitude and direction.

An object moving in a circular path with constant angular velocity has a constant tangential speed but is continually changing direction.

This change, only in the direction not in magnitude of the velocity vector, results in an acceleration of the object, normally to the circular path.

(FYI, Ringer is not referring to the transition at the top of the back swing but to a change in direction during the impact interval )

You're right; I already stated in an earlier post that velocity and acceleration involves magnitude and direction. I was sticking to straight line dynamics in order to define velocity and acceleration. I didn't want to complicate those definitions by including acceleration along an arc; I'm sure that isn't the change of direction that Ringer was talking about. And while there is technically a constant change in direction by an object moving along an arc, no person, besides one who has some knowledge of physics, sees that in a golf swing. That's why I used the transition; that's the point in the swing that everone perceives a change in direction, which made it easy to use in my explanation.

 

[mandrin]

Homer musta been smok'n when he wrote:

"Zero Deceleration is what would give maximum ball speed for any and all approach speeds. Speed and Prestress stiffen the Clubshaft for consistent resistance to Impact Deceleration."

And just how does one pre-stress the shaft and resist impact deceleration?

Ringer,

I am afraid that like Homer you are not quite up to par with science.
This subject has been discussed previously but let me try to explain such so that everyone can see immediately the basic fallacy inherent in Homer’s ‘scientific’ ideas re to impact.

(HK) "Zero Deceleration is what would give maximum ball speed for any and all approach speeds.”

- Impact occurs between to small masses – a fast moving clubhead and a stationary golf ball.
- The ball gets its kinetic energy / momentum from the impacting clubhead, which hence decelerates and slows down.
- Therefore zero clubhead deceleration implies no energy/momentum transfer taking place from clubhead to ball.

Homer’s idea that "Zero Deceleration is what would give maximum ball speed for any and all approach speeds” is hence clearly not conform to standard Newtonian physics.

(HK) “Speed and Prestress stiffen the Clubshaft for consistent resistance to Impact Deceleration."

Stiffness of the shaft is immaterial for all practical purpose during impact.
The force generated by the resistance of the shaft is negligible re to the very large forces generated during the 0.0005 sec of impact.

(R) “And just how does one pre-stress the shaft and resist impact deceleration?”

One does not resists impact deceleration. Impact simply happens lightning fast and totally out of control for the golfer.
Stressing the shaft is simply the consequence of torque being applied, it has no other significance.



Impact is governed by ‘conservation of momentum’, one of the most basic laws in classical mechanics since it remains valid in nuclear physics.

It is tell-taling Homer being completely wrong with regard with this very simple but fundamental law – Conservation of Momentum.

 

[lia41985]

mandrin,
I love your informative posts. Thank you for them.

 

[Ringer]

You're right; I already stated in an earlier post that velocity and acceleration involves magnitude and direction. I was sticking to straight line dynamics in order to define velocity and acceleration. I didn't want to complicate those definitions by including acceleration along an arc; I'm sure that isn't the change of direction that Ringer was talking about. And while there is technically a constant change in direction by an object moving along an arc, no person, besides one who has some knowledge of physics, sees that in a golf swing. That's why I used the transition; that's the point in the swing that everone perceives a change in direction, which made it easy to use in my explanation.

Bigwill, I was talking about the constant change in direction causing the accelleration. My hypothesis is that the ability to hold onto the lag for a longer period of time into the downswing would produce a later release of the lag angle and thus make the rate of change more exagerated.

I am not talking about what we see in the swing since I have yet to know anyone that can measure how much lag they have in their swing without seeing it on video.

 

[Ringer]

Ringer,

I am afraid that like Homer you are not quite up to par with science.
This subject has been discussed previously but let me try to explain such so that everyone can see immediately the basic fallacy inherent in Homer’s ‘scientific’ ideas re to impact.

(HK) "Zero Deceleration is what would give maximum ball speed for any and all approach speeds.”

- Impact occurs between to small masses – a fast moving clubhead and a stationary golf ball.
- The ball gets its kinetic energy / momentum from the impacting clubhead, which hence decelerates and slows down.
- Therefore zero clubhead deceleration implies no energy/momentum transfer taking place from clubhead to ball.

Homer’s idea that "Zero Deceleration is what would give maximum ball speed for any and all approach speeds” is hence clearly not conform to standard Newtonian physics.

(HK) “Speed and Prestress stiffen the Clubshaft for consistent resistance to Impact Deceleration."

Stiffness of the shaft is immaterial for all practical purpose during impact.
The force generated by the resistance of the shaft is negligible re to the very large forces generated during the 0.0005 sec of impact.

(R) “And just how does one pre-stress the shaft and resist impact deceleration?”

One does not resists impact deceleration. Impact simply happens lightning fast and totally out of control for the golfer.
Stressing the shaft is simply the consequence of torque being applied, it has no other significance.



Impact is governed by ‘conservation of momentum’, one of the most basic laws in classical mechanics since it remains valid in nuclear physics.

It is tell-taling Homer being completely wrong with regard with this very simple but fundamental law – Conservation of Momentum.

Hmmm.. this is a very good and concise answer Mandrin.. thank you.

I guess the only remaining question is why attempt to accelerate the club through the impact interval if it's completely hopeless?

 

[puttmad]

Hmmm.. this is a very good and concise answer Mandrin.. thank you.

I guess the only remaining question is why attempt to accelerate the club through the impact interval if it's completely hopeless?

R

I think this is a simple distance/time function..
With max lag the clubshaft is furthest from the "straight-line position" of the left arm/clubshaft (approx impact)..so the later the lag is held, the quicker the clubshaft has to move to reach the approx "straight line position" at impact...

Or put another way, the closer you can get your hands to the point in space they would be at impact, while still retaining the lag, the faster the clubhead/shaft needs to move to attain the "straight-line position" at impact..

My own feeling is that the longer the lag is held, the more input the golfer has to put in late, to enable the proper arm/shaft position at impact..whereas someone who doesn't hold the lag should have no problem reaching a straight line position, and in fact, probably, in extreme cases, be a flipper...

In simple terms anyway.....

 

[Ringer]

R

I think this is a simple distance/time function..
With max lag the clubshaft is furthest from the "straight-line position" of the left arm/clubshaft (approx impact)..so the later the lag is held, the quicker the clubshaft has to move to reach the approx "straight line position" at impact...

Or put another way, the closer you can get your hands to the point in space they would be at impact, while still retaining the lag, the faster the clubhead/shaft needs to move to attain the "straight-line position" at impact..

My own feeling is that the longer the lag is held, the more input the golfer has to put in late, to enable the proper arm/shaft position at impact..whereas someone who doesn't hold the lag should have no problem reaching a straight line position, and in fact, probably, in extreme cases, be a flipper...

In simple terms anyway.....

As the clubhead gets further away from the axis, the swing slows down. So how could your concept allow for the clubhead to maintain let alone speed up?

 

[mandrin]

Hmmm.. this is a very good and concise answer Mandrin.. thank you.

I guess the only remaining question is why attempt to accelerate the club through the impact interval if it's completely hopeless?

Ringer,

Don’t feel desparate there is still ample room for a more optimistic attitude.
If swing takes about 1 sec and impact 0.0005 sec you still have all of the remaining 0.9995 sec to do something useful using torque/force.

 

[mandrin]

mandrin,
I love your informative posts. Thank you for them.

lia41985,

Thanks, a little bit of appreciation goes a long way.

 

[gumper]

Keep it coming please Mandrin

Mandrin,

I don't understand half of what you say, but I love your posts. Obviously, we are all entitled to our anonymity, but would you be willing to share a little about your background? I'm also very curious as to what you consider to be Homer's major errors. Next, have you considered publishing about the golf swing? Finally, how does your knowledge of science help real-world golfers? By no means am I attacking you. I'm just trying to wade through your posts and figure out how they will help me score better. Does your knowledge help you?

I would be the first person to purchase anything that you and Brian worked on jointly!

gumper

P.S.- Do you know/agree with the theories of Dr. Zick, whom Brian has mentioned on occasion?

 

[Ringer]

Ringer,

Don’t feel desparate there is still ample room for a more optimistic attitude.
If swing takes about 1 sec and impact 0.0005 sec you still have all of the remaining 0.9995 sec to do something useful using torque/force.

Lucky for me I'm surrounded by FAA engineers so I can pose these questions to them.

FWIW they're complaining that this seems entirely theoretical and we have no actionable data.

It seems awfully difficult to measure the speed of the clubhead before and after impact then change out the variables in an experiment.

 

[puttmad]

....

As the clubhead gets further away from the axis, the swing slows down. So how could your concept allow for the clubhead to maintain let alone speed up?

Sorry you lost me on that one Steve. The whole point of lag is to create a situation for maximum clubhead speed..
Which axis are you talking about?

 

[mandrin]

Lucky for me I'm surrounded by FAA engineers so I can pose these questions to them.

FWIW they're complaining that this seems entirely theoretical and we have no actionable data.

It seems awfully difficult to measure the speed of the clubhead before and after impact then change out the variables in an experiment.

Ringer,

From you posts it is very clear that you still have plenty of homework to do.
Be very careful with your buddies, HK also worked in the same field, it is no guarantee for truth.

 

[hcw]

Translation

Ringer,

From you posts it is very clear that you still have plenty of homework to do.
Be very careful with your buddies, HK also worked in the same field, it is no guarantee for truth.

Ringer, let me translate the above "mandrin" for you:

I don't have any data and am actually making incorrect statements/assumptions about system in question so I'm just going to make a snide comment about you and your friends intellectual capabilities and not address the issue.

 

[mandrin]

Ringer, let me translate the above "mandrin" for you:

I don't have any data and am actually making incorrect statements/assumptions about system in question so I'm just going to make a snide comment about you and your friends intellectual capabilities and not address the issue.

hcw,

Glad to see that you have not changed, the same friendly way expressing opinions and playing in the dirt.
I very much appreciate it to see you taking some of your very valuable time to react to my posts.

 

[Ringer]

Sorry you lost me on that one Steve. The whole point of lag is to create a situation for maximum clubhead speed..
Which axis are you talking about?

Ok, how do you purpose that lag creates a situation for maximum clubhead speed? You say it's to get to an in line condition. Well, the longer the radius the slower the RPM with the same force... like a skater that extends their arms in a spin.

FWIW, I've discussed this with my colleagues and have determined where my error is but I'd like to keep the discussion going so that others might discover some answers too.

 

[Ringer]

Ringer,

From you posts it is very clear that you still have plenty of homework to do.
Be very careful with your buddies, HK also worked in the same field, it is no guarantee for truth.

I do my homework mandrin but I really don't particularly like the tone you're taking with me on it. I thought we were having an informative discussion but now you're rolling your eyes at me?

Be careful not to cop a "holier than thou" attitude. I'm not talking to Homer and the folks I'm talking to don't even play golf. That makes their opinions even more impartial than yours as far as I'm concerned.

I know the error in logic I've made with regards to my discussion with puttmad, but there is still lack of resolve on ours.

Since velocity is also a measure of direction, any SMALL change of direction during the .0005 seconds the clubface and ball are in contact is just as important as any other factor. Since speed is NOT the only factor in the golf balls behavior we must consider this possibility: A change in direction, however small it may be, could be an acceleration during impact which results in a minor increase of time that the ball and clubface are in contact. If the clubface were going at a constant velocity it would obviously cause a deceleration of the clubhead during impact. But that is not the case. We are not dealing with a zero accelleration situation. The clubhead IS changing direction even for that .0005. By sustaining the lag even longer into the forward swing we are ensuring that the change in direction is greater than it would if the person were casting the club.

 

[Bronco Billy]

Hi There

Ringer are you Talking about Sustained Force thru the .7 inch Impact Zone? I don't have the Answer but I do have a Question for Anyone..... Suppose a Train with a Cow Catcher in the Shape of a Golf Club Head Smashs a Golf Ball at a 100 mph...... Now the Train Ain't Gonna Slow Down a Hell of a Lot Thru the Impact Zone...... The Question is This..... All Conditions Being Equal will the Train Hit the Golf Ball Farther than a Mere Mortal?

Cheers