Was Homer Wrong?

[strav]

I for one welcome this debate.

I don't think this guy should be made the enemy.

Would it be cool if Homer was 100% right on everything? Hell yes.

What if he isn't? TGM gonna go down in flames? Hell no.

We're talking about small things here.

It's most important to get this right....

We have to remember.....when Homer died he had not hung up his "golf researchin pants"....so let's not....

Hi Birdie_Man. As you started this thread and welcomed the debate, you may be one of the last objective participants. If so, for your information, here is "Centrifugal force" from a neutral, namely Encyclopedia Britannica.

"Centrifugal Force, quantity, peculiar to a particle moving on a circular path, that has the same magnitude and dimensions as the force that keeps the particle on its circular path (the centripetal force) but points in the opposite direction. A stone whirling in a horizontal plane on the end of a string tied to a post on the ground is continuously changing the direction of its velocity and, therefore, has acceleration toward the post. This force is equal to the square of its velocity divided by the length of the string According to Newton’s second law; acceleration is caused by a force, which in this case is the tension in the string. If the stone is moving at a constant speed and gravity is neglected, the inward-pointing string tension is the only force acting on the stone. If the string breaks, the stone, because of inertia, will keep on going in a straight line tangent to its previous circular path; it is not the influence of a centrifugal “force” that will make the stone fly off in a radially outward direction.

Although it is not a real force according to Newton’s laws, the centrifugal-force concept is a useful one. For example, when analyzing the behaviour of the fluid in a cream separator or a centrifuge, it is convenient to study the fluid’s behaviour relative to the rotating container rather than, relative to the Earth; and, in order that Newton’s laws be applicable in such a rotating frame of reference, an inertial force, or a fictitious force (the centrifugal force), equal and opposite to the centripetal force, must be included in the equations of motion. In a frame of reference attached to the whirling stone, the stone is at rest; to obtain a balanced force system, the outward-acting centrifugal force must be included.

Centrifugal force can be increased by increasing either (1) the speed of rotation, (2) the mass of the body, or (3) the radius, the distance of the body from the centre of the curve. Increasing either the mass or the radius increases the centrifugal force proportionally, but increasing the speed of rotation increases it in proportion to the square of the speed; that is, an increase in speed of 10 times, say from 10 to 100 revolutions per minute, increases the centrifugal force by a factor of 100. Centrifugal force is expressed as a multiple of g, the symbol for normal gravitational force (strictly speaking, the acceleration due to gravity). Centrifugal fields of more than 1,000,000,000 g have been produced in the laboratory. "

[golf_sceptic]

`When I use a word,' Humpty Dumpty said, in rather a scornful tone, `it means just what I choose it to mean -- neither more nor less.'

Yes. Therein lies the problem. I offered the TGM copyright holder that I'd write some physics notes to accompany TGM, but never got a response.

[Mike O]

The words centripetal and centrifugal in physics have their dictionary meanings. centripetal=toward the centre, centrifugal=away from the centre. They are equal and opposite, action and reaction.

Most people get it wrong because they do not understand that the centripetal force acts on the stone, and the centrifugal force acts on the string (or the boy). We then get incorrect statements about the centrifugal force throwing the rock out and keeping the string taut and that sort of thing.

What keeps the string taut? The boy pulling on it.
What balances the centripetal force on the stone? Nothing, that's why it moves in a circle.

As a general rule, the more words used to describe the phenomenon,
the more errors will be introduced.

Interesting thread- although it seems like no one can clearly define all the issues/perspectives involved in clearly understanding the topic at hand. Although, some may take that personally- it's more just an observation regarding the thread. And I'm certainly not one who necessarily could clearly define all the issues involved- in fact I'd probably be more off base than most.

Just one piece of the puzzle and confusion- and I could be wrong but in relation to Newton's third law- "action reaction" and the notion of "centripetal" and "centrifugal"- there seems to be some discussion of the boy, string, rock- and some of it appears to me to be on the wrong track.

Newton's third law to me - just says that you can't create a force out of nothing. To me it's similar or it's "sister" concept is that you can't create or lose Matter - it just is. So if you push a car down the street in a straight line- then the equal and opposite force is your feet on the ground pushing against the earth in the opposite direction of the motion of the car. That's a simple example of the action/reaction concept.

I would think the proper context of this in relation to the golf swing would be to look at the "whole system". So imagine that you have the clubhead or rock moving in a straight line- attached to it is a golf shaft or string- now to prevent that thing from moving is a straight line you give a tug on the shaft or string and it curves/moves toward the tugging- that's the centripetal force. So in relation to Newton's third law- you ask what offsets or allows that inward tug to happen? Depending on the movement- i.e. amount of force involved etc.- how heavy the rock is compared to the mover it could be different- but to me the basic reaction forces would be the feet pushing against the earth- that force is away from center and allows the force towards center to take place.

So I'm limiting my comment to the specific issue of action/reaction forces- and I don't see it - in the larger picture - being the boy and the string or the boy and the rock, or the rock and the boy.

Hope I didn't further clutter the post- with something that isn't clear.

[golf_sceptic]

Nice post Mike.

You've got a good handle on things from my point of view, but by looking at the system as a whole (like yoda did with the string) it leaves greater scope for misunderstanding and it is harder to identify where the misunderstanding lies.

There is a nice student exercise that beginning physics students use about a man standing on bathroom scales whilst a lift accelerates upward. I'll run through it if anybody thinks it will help, but to go back to your examples...

If you push on your car the equal and opposite reaction is that the car pushes on you with the same force and in the opposite direction. You push on the earth and the earth pushes back, but this pair of equal and opposite forces will be different in magnitude to the push on car/car pushes back. The second phase of analysis is to look at each object and ask what forces are acting. On the car, your push. On you, the car's push and the ground's push. On the ground, your push.

With the rock and the string, if the mass of the string is important then we can't perform a correct analysis without separating considering the "string on rock/rock on string" and "boy on string/string on boy" pairs separately because they will have different magnitudes. We can't just say "boy on rock/rock on boy" without things getting very muddled.

This is where the man on scales in lift will help if you need more detail.

[Mike O]

Nice post Mike.

You've got a good handle on things from my point of view, but by looking at the system as a whole (like yoda did with the string) it leaves greater scope for misunderstanding and it is harder to identify where the misunderstanding lies.

There is a nice student exercise that beginning physics students use about a man standing on bathroom scales whilst a lift accelerates upward. I'll run through it if anybody thinks it will help, but to go back to your examples...

If you push on your car the equal and opposite reaction is that the car pushes on you with the same force and in the opposite direction. You push on the earth and the earth pushes back, but this pair of equal and opposite forces will be different in magnitude to the push on car/car pushes back. The second phase of analysis is to look at each object and ask what forces are acting. On the car, your push. On you, the car's push and the ground's push. On the ground, your push.

With the rock and the string, if the mass of the string is important then we can't perform a correct analysis without separating considering the "string on rock/rock on string" and "boy on string/string on boy" pairs separately because they will have different magnitudes. We can't just say "boy on rock/rock on boy" without things getting very muddled.

This is where the man on scales in lift will help if you need more detail.

Golf Sceptic- Just my perspective but it appears to me- that you have a significant communication problem. Don't know if you are aware of it or not. I don't say that in a derogatory tone or sarcastic tone- it's just the feedback I would give you - in order to improve your performance in the future. I'm assuming you know your subject but can't communicate it clearly. You've got 25 somewhat extensive posts on this thread/subject matter and it's my feeling that no one (at least myself) has made any progress in understanding your perspective or the context and importance of your point. Every new post doesn't get you any closer to the answer than the previous post.

My only guess to the problem is that the foundation of concepts that supports your viewpoint - that seems obvious to you is not obvious to your audience (me). When you build a concept, idea, system, theory- you can't get to the theory and take everything as self-evident- especially for teaching or describing it's functioning- you've got to essentially retrace the original route - in principle- not point by point- to it's basis- starting reference points- those things that you can see, touch, smell, hear. Homer had a similar problem- so you've got company. You've also got to understand when you mention any particular point- how other people might mis-interpret it and explain and what the wrong turns could be at any turn- so that you keep the reader on track.

So that's why very few people stuck it out with Homer- and very few will stick it out with you- (like me)- so when you ask "This is where the man on scales in lift will help if you need more detail." I'm thinking no thanks- because that post is going to be like the last 25 - not going to get me any closer to you answering and me understanding whatever you were talking about when this thread started.

That's just my feedback- hope it helps you.

[Mathew]

As for my tone on arrival here, have a look at what you
were saying in this thread prior to my contribution especially
the "centrifugally powered golf swing" snideness and the
person who decided to visit ISG to "tell us off", followed
after my post by the mockery about the "force with no name".

The primary lever assembly is powered into impact by a pressure against it... Centrifugal force does not 'power' the golf stroke... its effect is utilised. No where in the book does Homer ever reference the 'centrifugally powered swing'....

The problem is, I just don't know how seriously I can take someone who has yet to figure out that they do not need to press enter to go to a new line...lol

[golf_sceptic]

The primary lever assembly is powered into impact by a pressure against it... Centrifugal force does not 'power' the golf stroke... its effect is utilised.

What do you believe centrifugal force is acting on?

No where in the book does Homer ever reference the 'centrifugally powered swing'....

"This throw out action is termed herein as 'Centrifugal Acceleration' to indicate that Centrifugal Force (Centrifugal Reaction), not muscle, is propelling the Secondary Lever Assembly (the golf club) into Impact. So swingers are totally dependant on their skill at manipulating Centrifugal Force while Hitters are not."

I don't think my throwaway comment in the middle of a 16 page discussion constitutes any sort of a major misrepresentation. Certainly not to the extent that is it vulnerable to being shot down as if its the heart and sole of my proposition that Homer either misunderstood centrifugal force or deliberately mis-stated its application.

I ask again, what was the centrifugal force acting on?

The problem is, I just don't know how seriously I can take someone who has yet to figure out that they do not need to press enter to go to a new line...lol

...and people have a dig at me about what I write?!

If you are uncomfortable with what I write, ask questions.

[Mathew]

What do you believe centrifugal force is acting on?



"This throw out action is termed herein as 'Centrifugal Acceleration' to indicate that Centrifugal Force (Centrifugal Reaction), not muscle, is propelling the Secondary Lever Assembly (the golf club) into Impact. So swingers are totally dependant on their skill at manipulating Centrifugal Force while Hitters are not."

Are you saying that the word "propelling" does not have any association with force or power?

I ask again, what was the centrifugal force acting on?



...and people have a dig at me about what I write?!

If you are uncomfortable with what I write, ask questions.

The right forearm in a swingers stroke is driven into impact by the right shoulder going downplane to throw the entire right flying wedge into impact. You turn an axis to spin a flywheel.... the right arm continually being pulled towards a straight line at 90 degrees to the turning axis (think chinese drum), but the checkrein of the left arm maintains the bend in the right arm whilst the aiming point of pp3 controls the precision of the clubheads motion around two centers.

The centrifugal force is the secondary lever assembly and the right flying wedge getting thrown into impact via the right shoulder motion...just like a chinese drum.

"Drum technique. Understand?" - Mr Miyagi

"Is there a counterpunch in the technique?" - Daniel-san

"Ask drum." - Mr Miyagi

[golf_sceptic]

Ummm. Ok. What he said!

Sorry. If that means anything related to this discussion I don't know what it is. I'll just pick up on the words "centrifugal force" and try to keep things focussed on that. Otherwise we are back with Humpty Dumpty a few posts above, and words can mean whatever you want them to mean.

The centrifugal force is the secondary lever assembly and the right flying wedge getting thrown into impact via the right shoulder motion...just like a chinese drum.

...and the centrifugal force acts on?

[Mathew]

Ummm. Ok. What he said!

Sorry. If that means anything related to this discussion I don't know what it is. I'll just pick up on the words "centrifugal force" and try to keep things focussed on that. Otherwise we are back with Humpty Dumpty a few posts above, and words can mean whatever you want them to mean.



...and the centrifugal force acts on?

The right arm and flying wedge driving the secondary lever assembly and its onplane relationship with the axis of rotation - right shoulder... why do I have to repeat myself....

Spin a chinese drum, what powers it ?

Perhaps you think the strings are pulling the hands - if you do your intellect is rivaled only by that of garden tools...

Perhaps again you can reference the words "centrifugal powered swing" from the golfing machine....