I have been studying videos of swimmers and find what was once called the "S" stroke has almost disappeard.
I have noticed that flyers use it. But crawl swimmers have modified it so much that it is almost gone.
Has it been replaced completely or was it an optical illusion? Did underwater film show us it did not exist.
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Former Member
I've been sick the last few days and am probably not thinking straight, but, it seems to me that this experiment says something about mass versus viscosity. The article says the viscosity was doubled, if we presume that the mass of the guar gum was a small fraction of the mass of the water in the pool (or at least that the mass of the mix was much less than double the mass of water) then we should be able to predict differences in the effect if swimming is viscosity based or mass based. If mass was the dominant factor then the swimmers should have slowed down considerably as the drag of moving through the thicker, more viscous fluid is doubled while the mass that is being accelerated backward is increased by a much smaller amount. If viscosity was the dominant factor then the increased resistance to forward movement would be balanced by an equal resistance to the backward movement of the propelling limbs. The experimental results were the latter.
In reality when a body moves through a more viscous fluid a larger volume, and hence larger mass, is dragged along, so it is really two sides of the same coin, but even so, this extra step in providing an explanation seems to me to unnecessarily complicate the explanation versus just directly talking about drag, and it doesn't correspond to the intuitive model of pushing mass backward. Yes, yes, very pedantic. Sorry. :o
I've been sick the last few days and am probably not thinking straight, but, it seems to me that this experiment says something about mass versus viscosity. The article says the viscosity was doubled, if we presume that the mass of the guar gum was a small fraction of the mass of the water in the pool (or at least that the mass of the mix was much less than double the mass of water) then we should be able to predict differences in the effect if swimming is viscosity based or mass based. If mass was the dominant factor then the swimmers should have slowed down considerably as the drag of moving through the thicker, more viscous fluid is doubled while the mass that is being accelerated backward is increased by a much smaller amount. If viscosity was the dominant factor then the increased resistance to forward movement would be balanced by an equal resistance to the backward movement of the propelling limbs. The experimental results were the latter.
In reality when a body moves through a more viscous fluid a larger volume, and hence larger mass, is dragged along, so it is really two sides of the same coin, but even so, this extra step in providing an explanation seems to me to unnecessarily complicate the explanation versus just directly talking about drag, and it doesn't correspond to the intuitive model of pushing mass backward. Yes, yes, very pedantic. Sorry. :o
