I will offer you a reply, that represents my "best" understanding of the shaft bend phenomena.
I am going to presume that the shaft bend is "real" and not a camera artifact.
Let me start with the orbiting ball.
I have modified this diagram by adding dotted yellow/red lines. The red dotted line is in a perfect straight line relationship with the yellow dotted line - which means that there is an instantaneous relationship between cause-and-effect. If the hand (cause) moves in a circular arc, then the orbiting ball (effect) will respond instantaneously and also move in a circular arc (due to centripetal forces). There is no delay in this system when the string is continuously taut, and the system is in a state of balanced motion.
Now consider the golf swing.
I have placed yellow dotted lines and red dotted lines (as previously placed on other images) on your photos.
Starting with image 1
The clubhead sweetspot line (red dotted line) is lagging behind the hand pull line (yellow dotted line). I believe that this is due to clubhead inertia, and this phenomenon is only possible with a flexible shaft.
Image 2
The clubhead sweetspot line is ahead of the hand pull line. I believe that this is due to the fact that the hands are going through the tight radius turn of the small pulley of the endless belt - the time point where the club releases very fast. The fast releasing clubhead manages to get slightly ahead of the hand pull point - only because the shaft is flexible.
Image 3
I believe that the shaft has a double bend. The first bend (seen at the top of the shaft) is due to the same phenomenon as seen in image 2 where the central part of the shaft gets bent forward because the clubhead's speed is fractionally faster than the hand pull - during the pre-impact phase of the downswing. Then impact occurs, which slows the clubhead down. That causes the clubhead to get pushed back secondary to the collision - and that causes the peripheral end of the clubshaft to bend backwards while the central part of the clubshaft is still bent forwards. This snake-like bend phenomenon is only possible because the clubshaft is flexible.
I do not agree with either your observations or conclusions in your post #185 immediately above. However, I do appreciate your thoughtful reply and its visuals (even though your photo lines as identified are drawn incorrectly and thus misrepresent the invisible reality of Centrifugal Pull).
I know that you have this little area for your own stuff, a good idea - but I would advise you to look at some of this stuff about artifact on video camera footage:-
It may or may not be relevant to the above debate...but it must be worth you looking into in your usual thorough way ...it may save you some brain cells in the long run.... trying to use physics to explain an artifact is fairly fruitless...so I would want to make sure that image is real or artifact first.
I always suspected this "camera artifact" problem. I need to learn much more about this problem with rolling shutters that causes skewing of lines.
Jeff.
No worries, Jeff. You fight your corner hard - but maybe I do sometimes wonder whether you ever say to yourself "do I need to be in this corner in the first place?" - . Still good quality if your are springbok!
Perhaps you could do thread (within the confines of your zone - not sure if the protected zone is to protect "you" from "us" or vica versa! - joke!)on camera artifact in golf :
1)Rolling shutters and skew
2)Any camera and parallax error
etc..maybe a few more ...maybe the represenation of the "target line" on DTL shots (use line on ground or vertical shaft in ground with camera behind it...there must be a number of varaitions) - certainly gets confusing for players who use closed footline and open / square shoulders.... where are they aiming! Then you add in a "plane line" with inherent parallax problems...it is a wonder that video is ever helpful !!
How do the ultrafast cameras like the new Casios, EX-1 or 20 or whatever they are, which give 400-1000FPS do it?? Would love to know if you can find out. Putting those cameras and FPS in the right price bracket should lead to the clubface getting an accurate representation in the next few years of golf instruction. Bizhub for the masses
Yoda - seeing that you are at the end of the game, and my overactive mind has forced me into an overtime time period, I will address this post to other forum members who may be following this debate (game).
I have thought of another example.
Imagine five ice skaters skating on an ice rink while holding hands. Imagine that they travel at the same rate of speed in a straight line direction, so that they are all in a perfectly straight line. Imagine that they all stop exerting any active force to propel themselves forward, and that they are all coasting at the same speed.
Now imagine that that the ice skater at the one end of the line (which I will call the central end of the line) abruptly brakes to a sudden stop and then spins in a circle around the axis of his stationary feet. His extended arm will then spin around his axis of rotation and create a circle of rotation of a finite radius. His extended arm will exert a pull force on the second ice skater that will cause the second ice skater to passively rotate in a circle at roughly the same rpm as the first skater. This transmitted pull-force phenomenon will occur down the line of skaters. The fifth skater (last in line) will travel fastest and also transcribe a circle on the ice and that circle will have the greatest radius. If the fifth skater is traveling in a circle due to passive pulling forces, then there must be a centripetal force in play - even though the pulling force is essentially circular in nature. Not only is there a centripetal force in play, but the fundamental source of that centripetal force is the fact that the first skater's extended arm is traveling in a circular manner around the axis of rotation (the first skater's feet).
The "protective zone" is designed to protect you guys from my thinking (or lack of thought).
I may take your advice. I definitely plan to learn more about camera artifacts, and if I learn something useful, I will communicate my acquired "learning" in a new thread.
Yoda - seeing that you are at the end of the game, and my overactive mind has forced me into an overtime time period, I will address this post to other forum members who may be following this debate (game).
"Ok, so the prosecution it would appear is in deliberation now. Its been nearly an hour now. We can only suspect that they are frantically researching this last evidence presented by Golfbulldog that suggests the artifact is not to blame , that the shaft is a snake, based on the type of shutter used in both pieces of photographic evidence".
"Im going to ask an interested spectator here and forum member a question"
"Mr O.B. Left whats your take on what your seen unfold here today"
Mr left:
"I frankly dont know what this is all has to do with the pivot center but it sure has been interesting, Mr Lance is no doubt seeing a rise in ratings and viewership is on the whole way up, crazy stuff"
Court reporter
"We've seen some people leave the courtroom though"
Mr Left:
"Yes , true some people who were at the front of the court made their way slowly to the back and then sort of slipped out the door. Some are merely watching the clock like a student praying for the class to end so they can bolt"
Court reporter:
"but on the whole viewership it would appear is up"
Mr left:
"yes for sure but we'll have to see whether this is a bubble or not remember this is still in its infancy this whole format and certainly some left when the defense and Yoda rested. They're minds are made up I guess.
Court reporter:
"there are suggestions that the whole thing would be better off in the LaB"
Mr.Left
" I wonder if Plato had to deal with these sorts of irritating "show me" kinds of seekers. What are we in Missouri or something"
Court reporter
" Or misery maybe" I will say this however Jeff, is a game combatant and has never to my knowledge attacked anyone in a personal manner"
Mr Left
"Yes I like the guy. Very intelligent and probably has a formal education in the sciences of some sort. Not sure what his motivation is but.. He can just abandon something and then on the other hand.......... if this was a chess game youd have to question the manner in which he defended his shaft flex thing with a restating of Newtonian Law, sort of like defending a trapped pawn with your kind and queen". Im a Yodian , personally.. Who knows where this will end and what it will eventually imply to my golf swing" Im excited! As for me, my interests are only practical. I just want to compress my balls a little better.
Court Reporter
"Yes and weve lost Mike O. He was always compressing your balls."
Mr left
"no comment". "Lets just say that we all miss Mike".
Court Reporter
"For the record then. What type of shutter does your camera have"
Mr Left:
"I dont wish to comment but my lawyer will be issuing a statement shortly about the nature of my cameras CMOS shutter and the Vipers mechanical shutter."
Court reporter
"Thank you MR Left we'll wait for that and for the next exciting move from Jeff."
My comment about a centripetal force moving outwards along the string was plain stupidity!!!
I believe that there is no centripetal force moving in either direction along the string. I believe that centripetal force is better defined as a force that causes an orbiting object to travel in a circular path rather than a straight line path.
Consider my orbiting ball example again.
Consider the orbiting ball at position X. If the hand (positioned at point A) abruptly stopped moving, then the hand would no longer pull on the string. What would happen to the ball in the absence of a pull force. It would veer off in a straight line direction at an tangent to the circumference of the circle (orbiting path). Now what would happen if the hand continued to move at its constant rate of speed from position A to position B. It would continue to exert a constant pull on the orbiting ball via the continuously taut string. The direction of the pull (transmitted via the taut string) is circular - from position X to position Y. The string is not directly pulling the orbiting ball to the center of the circle. That central pull to the center (a centripetal pull) is only a mental concept. One can see the orbiting ball being pulled from position X to position Y and we can mentally/conceptually divide the forces pulling the ball into two components - a force that pulls the ball forward in a straight line direction, and a force that causes centripetal acceleration (causes the ball to move along a circular path rather than a straight line path).
Note that the string is angled relative to the circumference of the orbiting ball's circle of rotation - where the axis of rotation is in the dead center of the circle.
You wrote-: " In your model, the ball is the orbiting mass and the hand is the axis of rotation. The hand is not the centripetal force (as you incorrectly state). It is, after all, the axis!"
Wrong! The axis of rotation is the dead center of the circle - both the hand's circle of rotation and the orbiting ball's circle of rotation. The hand is in orbit around the axis of rotation (dead center of the circle) like the ball - the only difference being that the radius of the hand's orbit is much smaller than the radius of the ball's orbit. As the hand moves in a circular fashion, it inherently is exhibiting a centripetal force that keeps it moving in a circular manner. The ball is moving at exactly the same rpm speed as the hand (due to it being pulled by a continuously taut string). In that sense, the hand's centripetal acceleration is transmitted to the ball by the taut string (which is inert) and the ball therefore also centripetally accelerates. In other words, if the hand centripetally accelerates (by the act of rotating in a circular manner), then the ball has to centripetally accelerate - because the connecting string is continuously taut and the taut straight string passively transmits the pull force from the hand to the ball.
. Still good quality if your are springbok!
Hybrid Mode
