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  #111  
Old 02-02-2011
haschu33 haschu33 is offline
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Quote:
Originally Posted by Lawrence View Post
...
What I find odd about this thread is that there appear to be people here who think intuition is a better guide to how things work than science. It isn't, which is why science was invented. ...
Real intuition is based on experience.
Science is the better guide in the areas where it is the better guide, but not in the areas where it isn't. The trouble with people who's religion is science is that they fail to see the limitations of science.
Here is an example. In Germany there is a discussion whether homeopathy should be paid by health insurance or not. The science oriented people say no, because science is unable to prove that homeopathy works. I know by experience that homeopathy does work, from me, and from my dog when he ate rat poison. I have never seen something like that, he was a dying dog, and when he put his tongue into water with some homeopathic pills he converted in an instance into a living dog. Also people with children report that homeopathy works well with children.
The point is how to interprete the 'science cannot prove'. If you are a believer of science, you will say the reason is because homepathy doesn't work - otherwise it could be scientifically proven. If you have a more broader view you could get the idea that science simply fails to prove because the complexity of homeopathy might go way beyond the capabilities of today's science.
Science is an approximation to reality, it is an objective concept of reality. Science is not reality itself. Our brain deals with reality, it doesn't care about science. It doesn't even care what we think - to some degree.
Happyness is not objective, it is a subjective experience. Suffering is not objective, it is a subjective experience. Most of our life is subjective experience, not objectively verifiable.

Back to swimming. Little is known scientifically about swimming, surprisingly. As they say, water is too hostile an environment. We deal with drag, propulsion, vortices, waves, Newton, Bernoulli,... . Swimming is very complex.
Another example. Last time when I was swimming I did some laps practicing breaststroke kick. Flat on the water, face down, hands on my back, and then kick and glide. During the glide I felt clearly that I suddenly accelerated at some point. Now you cannot actually accelerate when you are gliding - no propulsion. I was the only person in the pool. I tried it again. It happened in every single glide. I tried to watch what happened and it became quite clear: the kick initiated a wave, that wave was faster then me gliding and when it passed me it gave me a tangible acceleration.
So, if we talk about hydrodynamics we also have to consider waves.

Swimming is very complex. What we try to do in this thread here is to isolate a single movement - spearing - and try to get its mechanics. To some degree it is bound to fail because the isolation of the movement is the fault. So the fault is already in the setup of how we observe. If you watch when science fails you usually find exactly this: the fault is in the setup already.

Our experience is the direct experience of our brain with reality. In swimming most that is known comes from experience. Sometimes science can clarify, or even prove that we interprete certain experiences in a wrong way. That is good, and it is very helpful. And understanding the reason why something works is very helpful. Although you can be a fast and wonderful swimmer without having any clue why. And vice versa, knowing perfectly why does not make you a good swimmer. You may know everything about hydrodynamics, the characteristic of water and so on, if you've never had the expereince of being in water and swimming you might sound good but your knowledge is completely worthless because without experience you don't know.
In general it is a good idea to use intuition as a guide where science fails or where you are out of scope of science, as long as it is backed up by experience. And when in our argumentation we start to use phrases like 'I think', then we know we lost the ground of 'clear and concise' argumentation.

And, in discussions like this one, we should keep in mind what our goal is. Do we want to contribute to clarification, or do we only want to prove that we are right?


Hang on in there...
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  #112  
Old 02-02-2011
Lawrence Lawrence is offline
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Some responses below.

Quote:
Originally Posted by CoachEricD View Post
Alright Lawerence, Now you are just being offensive. I know high school physics. I know that the arm can't accelerate forward with out a force. I never said it did. I have said that the shoulder does accelerate the arm forward. I have said that it takes much less force than most people think if the stroke finishes in a way that allows the allows the arm to flow in a circle. That way the ligaments of the shoulder can produce the force to turn the arm around and the shoulder only has to accelerate the arm slightly. I liken this to having a ball on a string and one end of the string fixed so the ball can only move in a circle. If you throw the ball tangentially to the circle, the string will provide the centripetal force needed to change the ball's direction. This allows the muscular effort you used creating force on the water during your pull to create the arm speed needed to recover the arm without speeding it up. So then you would say that the water is pushing on the hand equally. The arm is moving faster than the body, so the system now matches the bowling ball example and the body feels a forward tug. In this case, the tug does accelerate the body. As you say, the whole system (arm and body) will not accelerate,

If the whole system doesn't accelerate, that means there is no net forward force being applied to the system. So no propulsion.

but since the arm slows to the speed of the body at the end of the spear, the body accelerates some at that point.

Wrong. By your own analysis above, the arm is accelerated by pushing against the rest of the body, so the rest of the body gets sent in the other direction as the arm accelerates forwards. As the arm slows down it doesn't follow that the rest of the body accelerates forwards. What follows is that there is no longer a force pushing the rest of the body backwards.

(I can acknowledge that the arm does not need to speed up during recovery. And I can see that if the arm does accelerate during recovery it may slow the body slightly. This may explain why Terry advises to recover the arm slowly. I personally like to accelerate the arm during recovery, but this may only shorten the duration of the glide and get me to my next switch faster.

The arm has to speed up relative to the body during recovery, otherwise it would never get past the head and out there in front, fully extended.)

It is also clear that the finish of the stroke can be used to accelerate the arm separate from the body. See Shinji's "underwater finish" for this concept. This could also accelerate the arm in relation to the body without affecting the force moving the body forward.

Again, your terminology leaves me struggling to follow the point. 'Finish'? The arm accelerates relative to the body when it is extended forward. That's why it leaves the body behind and extends forwards. If by 'finish' you mean the catch, no one denies that the catch involves hand and arm pressing against the water and creating an equal and opposite propulsive force.

To my credit, part of my graduate work was done in an anatomical physics lab looking at the physics of shoulder movement. i do understand the concepts present here. I may get the details and equations off, that work was 15 years ago, but the concepts have been demonstrated in peer reviewed scientific research.

Sorry, I respond only to arguments. Appeals to authority count for nothing.

Second, I know the vorticees are not solely responsible for forward motion. As I said, the hypothesis says it adds a small fraction to that forward force.

Perhaps vortices do help propel the swimmer. You offered an elucidation of how that happens. I said it was too fantastic for words. I think it is.

We know that any eddies spinning the opposite direction resist the body's movement.

Do we? How do we know that?

That is part of the resistance the water provides. The idea is that we can observe those eddies and learn to produce more that are beneficial than those that are not.

Doubtless.

This came from observations of elite swimmers and competitive swimmers that have not reached the elite level. Those at the elite level produce more eddies that benefit them than the swimmers at the sub-elite level.

Do they? How do we know that?

As I understand, and I could be wrong about this, swim scientists are just beginning to explore this possibility to see what components of this technique are trainable. Also, this hypothesis is not absurd because it has been published in peer reviewed science journals in fish models. Hydrodynamic engineers were trying to figure out how trout can hold their place in a moving stream with far less metabolic energy (producing the forces) that are required to hold a static fish model in the same stream. They found that the fish instinctively bend their body around the eddies produced by rocks and sticks in a way that pushes them upstream. When they moved their model fish in a similar fashion, the force on a string used to hold the model in place was reduced. If the strings force was reduced, then there must be another force coming from something else. The only independent variable was the movement around the eddies. So that was the only observable possibility for the source of the force. Of course we cannot match the efficiency of a fish, but we might be able to take advantage of this behavior.

In short, eddies may somehow help fish and humans swim. Nothing you have said explains how. This thread is about explaining how forward motion happens. Simply saying 'it's something to do with eddies' doesn't get us very far. One might as well say 'it's something to do with how one moves in the water'.

And I dropped this earlier, but I have evidence that counters your jumping analysis as well. A study done at SF State, which has a very strong kinesiology and physical therapy program, looked at volleyball players jumping ability with 4 jumping methods - standing jump with the arms at the sides, standing jump with the arms starting at the shoulders and pressing up during the jump, a wind up prep with a jump with the hands held at the sides during the jump and a full wind up and jump with the arms swinging overhead. In every case, the jump with the arms finishing overhead was higher than the similar jump with the hands at the sides. So the arms finishing overhead does have some effect. Again, this was master's thesis level work reviewed by several scientists working in the field.

Indeed. My earlier post explained these results in terms of Newton's laws. Your 'evidence' doesn't counter my analysis. It is simply a summary of findings that my analysis explains.
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  #113  
Old 02-02-2011
Lawrence Lawrence is offline
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Quote:
Originally Posted by haschu33 View Post
Real intuition is based on experience.
Science is the better guide in the areas where it is the better guide, but not in the areas where it isn't. The trouble with people who's religion is science is that they fail to see the limitations of science.
Here is an example. In Germany there is a discussion whether homeopathy should be paid by health insurance or not. The science oriented people say no, because science is unable to prove that homeopathy works. I know by experience that homeopathy does work, from me, and from my dog when he ate rat poison. I have never seen something like that, he was a dying dog, and when he put his tongue into water with some homeopathic pills he converted in an instance into a living dog. Also people with children report that homeopathy works well with children.
The point is how to interprete the 'science cannot prove'. If you are a believer of science, you will say the reason is because homepathy doesn't work - otherwise it could be scientifically proven. If you have a more broader view you could get the idea that science simply fails to prove because the complexity of homeopathy might go way beyond the capabilities of today's science.
Science is an approximation to reality, it is an objective concept of reality. Science is not reality itself. Our brain deals with reality, it doesn't care about science. It doesn't even care what we think - to some degree.
Happyness is not objective, it is a subjective experience. Suffering is not objective, it is a subjective experience. Most of our life is subjective experience, not objectively verifiable.

Back to swimming. Little is known scientifically about swimming, surprisingly. As they say, water is too hostile an environment. We deal with drag, propulsion, vortices, waves, Newton, Bernoulli,... . Swimming is very complex.
Another example. Last time when I was swimming I did some laps practicing breaststroke kick. Flat on the water, face down, hands on my back, and then kick and glide. During the glide I felt clearly that I suddenly accelerated at some point. Now you cannot actually accelerate when you are gliding - no propulsion. I was the only person in the pool. I tried it again. It happened in every single glide. I tried to watch what happened and it became quite clear: the kick initiated a wave, that wave was faster then me gliding and when it passed me it gave me a tangible acceleration.
So, if we talk about hydrodynamics we also have to consider waves.

Swimming is very complex. What we try to do in this thread here is to isolate a single movement - spearing - and try to get its mechanics. To some degree it is bound to fail because the isolation of the movement is the fault. So the fault is already in the setup of how we observe. If you watch when science fails you usually find exactly this: the fault is in the setup already.

Our experience is the direct experience of our brain with reality. In swimming most that is known comes from experience. Sometimes science can clarify, or even prove that we interprete certain experiences in a wrong way. That is good, and it is very helpful. And understanding the reason why something works is very helpful. Although you can be a fast and wonderful swimmer without having any clue why. And vice versa, knowing perfectly why does not make you a good swimmer. You may know everything about hydrodynamics, the characteristic of water and so on, if you've never had the expereince of being in water and swimming you might sound good but your knowledge is completely worthless because without experience you don't know.
In general it is a good idea to use intuition as a guide where science fails or where you are out of scope of science, as long as it is backed up by experience. And when in our argumentation we start to use phrases like 'I think', then we know we lost the ground of 'clear and concise' argumentation.

And, in discussions like this one, we should keep in mind what our goal is. Do we want to contribute to clarification, or do we only want to prove that we are right?


Hang on in there...
No one denies intuition and experience may offer useful insights. Some here seem to doubt that science may offer useful insights. Well, that's their issue. I wonder if they carry that view with them to the hospital, dentist, doctor or pharmacy. Or when deciding whether to buy an iPhone. Perhaps swimming is a special case, because we have 'direct experience' of doing it, whereas I assume no one here can design a drug or build an iPhone. I note in passing that the TI handbook starts by explaining why the stroke works in engineering terms. Engineering analyses are basically analyses based on Newtonian physics. If that is news to anyone, ask an engineer.

As I said in an earlier post to Terry, I don't come to the table with a preconceived notion of which sort of evidence or concept will better help me understand swimming. I will take what I can get. Ruling out certain leads in advance is really a species of superstition. Where did that get anyone?
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  #114  
Old 02-02-2011
terry terry is offline
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Quote:
Originally Posted by Lawrence View Post
What I find odd about this thread is that there appear to be people here who think intuition is a better guide to how things work than science.
It seems you are missing the point. Of swimming practice, and of this Forum itself - or at least what I believe the overwhelming majority of those who frequent it are seeking.

I was a notably poor and unmotivated student of science in HS and college. I was unable to relate the dry material I was expected to memorize and replay to anything I really cared about. The day I was liberated from taking tests on that stuff was a banner day.

My interest in science was revived only when I became curious for explanations of things I observed as a coach or experienced as a swimmer. I don't believe those explanations played any role in helping me coach - or swim - better. Rather they satisfied a desire to understand and provided a few rhetorical tools for persuasion of those who wanted 'proof.'

I swim today primarily because it's the healthiest way I know to experience Flow States and because I expect it will help me remain strong and supple for many more years.

Everything I've learned in swimming that I most value, and my happiest moments, have been the product of direct experience, physical intelligence, and, yes, intuition.
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  #115  
Old 02-02-2011
haschu33 haschu33 is offline
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Quote:
Originally Posted by Lawrence View Post
No one denies intuition and experience may offer useful insights. Some here seem to doubt that science may offer useful insights. Well, that's their issue. I wonder if they carry that view with them to the hospital, dentist, doctor or pharmacy. Or when deciding whether to buy an iPhone.
He, where is your clarity and conciseness? As far as I remember nobody in this thread questioned whether science can give usefull insights. And doctors, iPhone etc are a slightly irrelevant here, aren't they?
Remember: when we are swimming, we don't deal with Newton. We deal with forces that we call gravity, drag, propulsion etc. Newton was the one who formulated the rules that can be derived from our experience with those forces. The forces don't follow Newton. In fact they don't know him and don't even care about him ;-)


Quote:
Originally Posted by Lawrence View Post
Perhaps swimming is a special case, because we have 'direct experience' of doing it, whereas I assume no one here can design a drug or build an iPhone. I note in passing that the TI handbook starts by explaining why the stroke works in engineering terms. Engineering analyses are basically analyses based on Newtonian physics. If that is news to anyone, ask an engineer.
Yes, this is a swimming forum and we all have direct experience of swimming. And yes, most of us are not engineers.
The fact that the physics of engineering analyses is based on Newton is obvious but might be new to some here. As you said, you might well be a wonderful swimmer without ever hearing the name Newton. We deal with drag and balance, and knowledge of Newtonian physics can help immensely. Again I think there is no dispute here.


Quote:
Originally Posted by Lawrence View Post
As I said in an earlier post to Terry, I don't come to the table with a preconceived notion of which sort of evidence or concept will better help me understand swimming. I will take what I can get. Ruling out certain leads in advance is really a species of superstition. Where did that get anyone?
Again full agreement. I didn't see anyone ruling out anything.
Or did you want to rule out the influence of eddies? :-)


Was there anything we didn't agree upon? I am afraid I lost the point...
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  #116  
Old 02-02-2011
Lawrence Lawrence is offline
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Terry and haschu, the following is taken from Terry's initial post on this thread:

Thanks to John's engineering perspective, we now have a much more comprehensive explanation for why TI technique results in Perpetual Motion Swimming.

I agree it's possible to be a great swimmer without understanding how one does it, other than in intuitive terms, or what Terry calls physical intelligence. But statements like the one above have made me think I'm not alone in being interested in applying other forms of intelligence to the question how one does it. Perhaps I'm mistaken.
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  #117  
Old 02-02-2011
terry terry is offline
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Quote:
Originally Posted by haschu33 View Post
Do we want to contribute to clarification, or do we only want to prove that we are right?
Should be 'engraved' on the opening page for every Forum on the web.

Haschu. Your comments about the complexity of hydrodynamics and the real difficulty of pinning down causes for things we observe or experience are more valid than nearly anything I've ever read in research publications that focus on the 'science' of swimming.

In particular, while studying nature's most amazing 'swimming machines' like yellowfin tuna and dolphins, scientists have confessed the inadequacy of their tools and methods to explain phenomena such as those creatures ability to achieve speeds far higher than their available horsepower would predict.

But those moments such as the extra bit of propulsion you experienced while playing with breast kick that clue us in to the value of simply 'noodling around' with a variety of simple movements, rather than mindlessly plowing back and forth to 'get the yards in.'

It was exactly such a moment that alerted me to the potential of the Mail Slot entry. I've been in search of a more complete explanation for that ever since - mainly because I'm a teacher. John Eckert's ideas seemed more intuitively plausible to me than anything else I'd heard in the 10 years since I made that fortuitous discovery.
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  #118  
Old 02-02-2011
haschu33 haschu33 is offline
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Quote:
Originally Posted by terry View Post
...
Haschu. Your comments about the complexity of hydrodynamics and the real difficulty of pinning down causes for things we observe or experience are more valid than nearly anything I've ever read in research publications that focus on the 'science' of swimming.
...
Oh, thanks - I had and have no intentions of doing comments of such a nature. Basically just posting my point of view which is nothing but another limited view of reality.
But maybe that is the point in forums like this - we can overcome some of our personal limitations by following other's views - like a swimmer in the slipstream ;-)


Quote:
Originally Posted by terry View Post
...It was exactly such a moment that alerted me to the potential of the Mail Slot entry. I've been in search of a more complete explanation for that ever since - mainly because I'm a teacher. John Eckert's ideas seemed more intuitively plausible to me than anything else I'd heard in the 10 years since I made that fortuitous discovery.
Yes, I know, and I hope it is not daunting that I didn't get the propellor analogy.
I have the impression though that you don't give up so easily...


Had to look up 'fortuitous'... always learning :-)
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  #119  
Old 02-02-2011
FrankJ FrankJ is offline
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I want to comment that I fully agree with Lawrence in his approach to understanding how some of the basic swimming principles we apply works

We like to think that other principles we vouch for are based on engineering (scientific) principles, as outlined at the beginning of this thread. I remember the freestyle made easy book is not devoid of scientific discourse on basic principles of swimming and where traditional teaching fails to take these principles into account. Nor we shy from addressing how learning happens at a neurological level.

Now, when faced with closer scrutiny, a random line is drawn, and we welcome instead as a meter of judgment concepts such as feeling and intuition. These have a place, but not in answering some legitimate question such as how and why hip drive contributes to propulsion, and why spearing at one angle works better than at others.

The discourse on Newton came by not because of sterile academic interest, but because it was suggested that one can propel forward in the water without pushing water back. Other fallacies have since then been proposed. Nothing wrong with being in error, we all do often, but when conversing, pointing out the error, as Lawrence does, is not rude, but a good way to progress and to avoid endless, useless debate based on thin air.

What I see now is a general retreat behind vague arguments. I get then that the answers to the questions: (1) how does hip drive contribute to propulsion and (2) why is spearing closer to the head better than further ahead and (3) why is it better to spear shallow like Shinij is: because of feeling and intuition?

I can promise, since peer-review has been quoted by one of the coaches, none of the responses given to Lawrence would be even looked at in the most ludicrous of scientific circles.
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  #120  
Old 02-02-2011
haschu33 haschu33 is offline
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Quote:
Originally Posted by fjconti72 View Post
...
I can promise, since peer-review has been quoted by one of the coaches, none of the responses given to Lawrence would be even looked at in the most ludicrous of scientific circles.
Yes, most likely. But the same will happen to Lawrence responses. We are in the same boat here.
And consider this:
Quote:
Originally Posted by terry View Post
'In particular, while studying nature's most amazing 'swimming machines' like yellowfin tuna and dolphins, scientists have confessed the inadequacy of their tools and methods to explain phenomena such as those creatures ability to achieve speeds far higher than their available horsepower would predict.
Science also cannot answer 'some legitimate question such as how and why hip drive contributes to propulsion, and why spearing at one angle works better than at others.'
Too complex.
Which doesn't mean that the discussion here is useless, on the contrary. It is good to get an approximation as close as possible, and I think a lot of important aspects did pop up.
But if we deny experience in a complex situation such as swimming we will completely miss the point. We would discuss a Fata Morgana then.

We try to find the explanation for something that works. Developing an explanation first and then try if it works will not neccessarily fail, but in this case the explanation(s) - or science - itself is too vague to be able to base anything on it.
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