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Re: Physics debate
Posted: Tue Jan 10, 2023 7:44 pm
by GrimSurfer
It’s been beaten to death @leon. Another diagram won’t change anything. Folks either accept and understand the laws of physics or they don’t.
Re: Physics debate
Posted: Tue Jan 10, 2023 7:54 pm
by fisheater
GrimSurfer wrote: ↑Tue Jan 10, 2023 6:56 pm
lowangle al wrote: ↑Tue Jan 10, 2023 6:33 pm
I think you have demonstrated a great enough interest in cable bindings to warrant getting a pair to try for yourself.
My original post simply stated that the way some folks think NN 3 pin 75 mm cable bindings work isn’t the way they actually work (if the laws of physics are right, which they invariably are in such cases).
If you feel offended by this, write your congressman or declare jihad on the Royal Society. You could even protest outside the National Academy of Science.
Hold on, I thought that it has finally been settled that the force it takes the heel to raise is applied to the lever (boot, foot musculature, and bones [tarsals]) upon which said force is transmitted to the ball of the foot and to the ski in front of balance point.
If this hasn’t been established by the consensus of skiers by both logic, mechanical expertise, and decades of actually performing Telemark turns on skis with real skis? Was this transfer of energy of the heel also understood to be the same dynamic in place utilizing the Xplore binding?
Maybe I’m wrong.
Did I ever tell anyone about the guy from a far away land whom visited a tribe of reindeer herders. These reindeer herders had been living in symbiosis with their environment for years. Now here’s the rub, the new stranger had read a book about reindeer six months previously. So he politely explained to these dumb herders that they really didn’t understand what they were doing. It was amazing that they had accomplished anything considering their lack of understanding. When they protested, and offered explanation, their explanation was not refuted directly, only that they really didn’t understand.
Now if I wanted to learn to Telemark turn, I would pay attention to what
@lowangle al has to say, but that’s only because I understand what’s involved in making the turn. It’s quite possible if I had all understanding of the science of matter, motion, and energy, I would indeed be able to deduce the fact Al can ski well is dumb luck at best. I could scientifically prove he had no knowledge of what he was doing, and any success he had was random chance. The fact that I couldn’t Telemark turn was of course a lack of data, and had nothing to do with my inability to actually understand what goes on with matter, motion, and energy in a Telemark turn. Because if one who all knowing does not see, it certainly doesn’t exist.
Re: Physics debate
Posted: Tue Jan 10, 2023 7:56 pm
by leon
GrimSurfer wrote: ↑Tue Jan 10, 2023 7:44 pm
It’s been beaten to death
@leon. Another diagram won’t change anything. Folks either accept and understand the laws of physics or they don’t.
On the contrary, this post is very active in deed. I saw the ski diagrams, but not one with force vectors everyone is arguing about.
@GrimSurfer I think that if there is a misunderstanding of Newtonian dynamics, and Newtonian dynamics are best understood with free-body force vector diagrams, then this discussion or argument or whatever it is can really benefit from an accurate force diagram. I can give it a try but leaving this task to a non-physicist risks muddying the discussion rather than clarifying it.
Re: Physics debate
Posted: Tue Jan 10, 2023 8:06 pm
by fisheater
leon wrote: ↑Tue Jan 10, 2023 7:56 pm
GrimSurfer wrote: ↑Tue Jan 10, 2023 7:44 pm
It’s been beaten to death @leon. Another diagram won’t change anything. Folks either accept and understand the laws of physics or they don’t.
On the contrary, this post is very active in deed. I saw the ski diagrams, but not one with force vectors everyone is arguing about. @GrimSurfer I think that if there is a misunderstanding of Newtonian dynamics, and Newtonian dynamics are best understood with free-body force vector diagrams, then this discussion or argument or whatever it is can really benefit from an accurate force diagram. I can give it a try but leaving this task to a non-physicist risks muddying the discussion rather than clarifying it.
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@leon Find me one accomplished Telemark skier that will say that a cable or NTN binding does not transfer the energy from lifting the heel to an area in the front of the ski beyond balance point. Just find one.
Re: Physics debate
Posted: Tue Jan 10, 2023 8:10 pm
by leon
fisheater wrote: ↑Tue Jan 10, 2023 7:54 pm
Hold on, I thought that it has finally been settled that the force it takes the heel to raise is applied to the lever (boot, foot musculature, and bones [tarsals]) upon which said force is transmitted to the ball of the foot and to the ski in front of balance point.
Your description makes total sense. I’m just trying to visualize the force vectors in one neat diagram and my brain is incapable (or unwilling) to convert your beautiful prose to dots and arrows. Maybe it’s impossible to visualize the elegant and ephemeral forces in a telemark turn with a group of arrows in a 2-dimensional plane, but I figured if anyone can do it it’s the physics brain trust in this discussion.
Re: Physics debate
Posted: Tue Jan 10, 2023 8:19 pm
by fisheater
Leon, I can make rudimentary mechanical drawings. However, I am not up to expanding the effort. For me drawing requires effort. It’s something I do to get architects and engineers to go along with me. My prose doesn’t work with them either!
Please don’t take my word that the energy transfers from lifting the heel to the front of the ski. Please ask the next 20 accomplished Telemark skiers you encounter. I am assuming their answers should offer more clarity than I can.
Re: Physics debate
Posted: Tue Jan 10, 2023 8:44 pm
by Stephen
lowangle al wrote: ↑Tue Jan 10, 2023 6:08 pm
If Isaac Newton skied, he'd be telling you that cables create force. He'd probably wonder if you were dropped on your head.
@lowangle al, STRICTLY speaking, cables to not CREATE force.
This is where we have been hung up all along.
They do TRANSMIT force, which is what I belive you mean, and is what I UNDERSTAND you to be saying.
If I have that wrong, please feel free to flame me!!!!
Re: Physics debate
Posted: Tue Jan 10, 2023 8:48 pm
by Stephen
GrimSurfer wrote: ↑Tue Jan 10, 2023 6:56 pm
lowangle al wrote: ↑Tue Jan 10, 2023 6:33 pm
I think you have demonstrated a great enough interest in cable bindings to warrant getting a pair to try for yourself.
My original post simply stated that the way some folks think NN 3 pin 75 mm cable bindings work isn’t the way they actually work (if the laws of physics are right, which they invariably are in such cases).
If you feel offended by this, write your congressman or declare jihad on the Royal Society. You could even protest outside the National Academy of Science.
I think this is all one big misunderstanding, based on colloquial usage of terminology.
The colloquial's understand what they mean among one another.
When a scientist shows up and tries to "educate" them, things go pear shaped.
No disrespect meant to anyone, honest.
Re: Physics debate
Posted: Tue Jan 10, 2023 9:25 pm
by Lhartley
leon wrote: ↑Tue Jan 10, 2023 7:42 pm
This is a really fascinating discussion. Not sure if it will help my skiing, but perhaps expand my background knowledge of mechanics.
I am not a physicist, but I tried to follow along as best as I could. There were a few mentions of free-body diagrams by @GrimSurfer I believe, maybe others as well. Perhaps one of the physics-inclined members, or @GrimSurfer himself, can draw and post the free-body diagram of forces at play. I think it would really summarize the discussion well and perhaps give everyone a visual representation of the forces and dynamics between the snow surface, ski, binding, boot, and body.
Leon, I also find this discussion fascinating. I'm new to to the telemark turn, and don't find it particularly difficult to perform. But I still don't really understand the theory behind it or why it works. It's has however made me want to try more active bindings however and get more of a feeling for the energy transfer described.
Re: Physics debate
Posted: Wed Jan 11, 2023 12:41 am
by CwmRaider
Stephen wrote: ↑Tue Jan 10, 2023 8:48 pm
GrimSurfer wrote: ↑Tue Jan 10, 2023 6:56 pm
lowangle al wrote: ↑Tue Jan 10, 2023 6:33 pm
I think you have demonstrated a great enough interest in cable bindings to warrant getting a pair to try for yourself.
My original post simply stated that the way some folks think NN 3 pin 75 mm cable bindings work isn’t the way they actually work (if the laws of physics are right, which they invariably are in such cases).
If you feel offended by this, write your congressman or declare jihad on the Royal Society. You could even protest outside the National Academy of Science.
I think this is all one big misunderstanding, based on colloquial usage of terminology.
The colloquial's understand what they mean among one another.
When a scientist shows up and tries to "educate" them, things go pear shaped.
No disrespect meant to anyone, honest.
I agree with what you say, and i know you are not generalizing, but i want to emphasize that there are several scientists here who aren't particularly pedantic about terminology or trying to educate anyone. That the increasing cable tension generates rotational torque of the ski around the pivot point, resulting in increased pressure under the front of the ski is obvious to me. And my impression is that that is also the viewpoint of the telemarkers here.
This is a forum, not a peer reviewed funding proposal for the national science Foundation.