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# The "Virtual" bump.... real or fiction? - Page 5

Quote:
Originally Posted by Skidude72

Well....not really.  Virtual Bump (VB) is a function of line and the pitch of the ski slope.

Now of course, as we agree, if you go straight we wont have a VB.....so we must be turning, thus turning forces must be there....but I think that is causing the confusion.  Think cause/effect......does the VB cause the forces? or do the forces cause the VB?

I said that the VB must have turn forces to exist. So, you want to rename turn with "line" is that it now? You need to make a turn, or you need to take a line that is not straight. Simple. That is what I said and you said no...

Forces and line are not the same thing.  Related, yes.  But not one in the same.

I didn't say forces and line are the same thing. I said that you were calling lines, turns.... What line you choose to ski, not what force you choose to ski. Different lines will create different forces. I said this because you said that VB is a function of line and pitch of ski slope - not quite accurate and you had responded with a NO to my saying that you needed to turn to have the VB.... line, turn, I don't care what you call it. You need to turn to have VB.

Well the VB causes the forces.  The line we ski, determines the forces we feel/generate.  I am sure you will agree with that.  However we tend to think of the line we ski in a 2-D plane parallel to the ski slope....this is an oversimplification of reality.  We actually ski in and our line is actually 3D.  We go left/right and down (with maybe some up in certain instances , such as mogul, or big knoll...).

The VB concept explains this, and shows the forces that our line through a 3D world generates.

Give me another break. Your VB is virtual, remember. The VB does not and cannot cause anything. Without the turn forces of gravity and momentum, you would not have any VB. Well that is not true....see below.

It does not cause the forces. The line or turn you ski does determine what forces you will feel/generate. The VB does not create or cause the forces. Can you explain what you mean here further....seems very contradictory.  You seem to agree that line determines the forces....VB is just a map of our line in 3D.....but that line...when named VB,  doesn't create the forces? Line=turn. Line/turn is part of what determines the forces you will have to deal with. The VB is a description of what will occur as you deal with those forces. How is that?

Your decision to ski a certain line or turn and manage the forces in a certain way cause you to feel the VB in a

certain amount - same with rebound, vaulting and whatever.  I think it will help if you just stick to the forces, and what causes them....and not worry about how we manage them until later. Line=turn. Line/turn is part of what determines the forces you will have to deal with. The VB is a description of what will occur as you deal with those forces. Forces caused by gravity, momentum. Where you go, how fast you go, etc. will determine the nature of the forces you will have.

I think that is the exact opposite to Rebound, which suggests the forces cause the rebound....plus the forces come from a 2D view of line...not reality.

I guess you do think rebound is a 2D view. I'm sorry if your view of rebound is 2D. Nobody ever said that. It's not only 3D, but it's actually 4D when you consider it's time element - momentum through space. What causes rebound, I'll repeat again, maybe in terms that you will allow -  You have a skier moving through space, on snow choosing a line or turn to make. Because of the laws of our physical world, there will be gravity and momentum mainly and the centripetal/centrifugal forces because of how he uses his skis and his body on the snow. These are turn forces. How he decides to manage these turn forces will determine exactly how much rebound and VB he will experience - and then have to manage that too... What is so 2D about that? Nothing.

What I wrote was is that Rebound has a 2D view of LINE.  If I got that wrong...fine....please explain how Rebound or what Rebound teaches us about 3D line, and how it is used, or what insights Rebound offers us in this regard.

It's how you see things in 3D or 2D. You like to think of rebound as a 2D line, I think of it as a 3D spatial/time relation. No different insights than with VB, huh?

Running out of colours!

Quote:
Originally Posted by Cookie Bewley Hale

Originally Posted by Skidude72

Well....not really.  Virtual Bump (VB) is a function of line and the pitch of the ski slope.

Now of course, as we agree, if you go straight we wont have a VB.....so we must be turning, thus turning forces must be there....but I think that is causing the confusion.  Think cause/effect......does the VB cause the forces? or do the forces cause the VB?

I said that the VB must have turn forces to exist. So, you want to rename turn with "line" is that it now? You need to make a turn, or you need to take a line that is not straight. Simple. That is what I said and you said no...

Forces and line are not the same thing.  Related, yes.  But not one in the same.

I didn't say forces and line are the same thing. I said that you were calling lines, turns.... What line you choose to ski, not what force you choose to ski. Different lines will create different forces. I said this because you said that VB is a function of line and pitch of ski slope - not quite accurate and you had responded with a NO to my saying that you needed to turn to have the VB.... line, turn, I don't care what you call it. You need to turn to have VB.

What is not quiet accurate about it?  I think you will find it is very accurate.

Well the VB causes the forces.  The line we ski, determines the forces we feel/generate.  I am sure you will agree with that.  However we tend to think of the line we ski in a 2-D plane parallel to the ski slope....this is an oversimplification of reality.  We actually ski in and our line is actually 3D.  We go left/right and down (with maybe some up in certain instances , such as mogul, or big knoll...).

The VB concept explains this, and shows the forces that our line through a 3D world generates.

Give me another break. Your VB is virtual, remember. The VB does not and cannot cause anything. Without the turn forces of gravity and momentum, you would not have any VB. Well that is not true....see below.

It does not cause the forces. The line or turn you ski does determine what forces you will feel/generate. The VB does not create or cause the forces. Can you explain what you mean here further....seems very contradictory.  You seem to agree that line determines the forces....VB is just a map of our line in 3D.....but that line...when named VB,  doesn't create the forces? Line=turn. Line/turn is part of what determines the forces you will have to deal with. The VB is a description of what will occur as you deal with those forces. How is that?Well it is wrong.  Virtual bump has nothing to do with "after the fact"....Virtual Bump is not rebound, nor is it vaulting...you cannot minimise it with things like flexion....it is determined by line and pitch.  full stop....again like a real bump...the bump does not get smaller because you flexed when going over it....the size of the bump is the size of the bump.

Again "it" and "dealing with it" are separate.....the VB concept does not go into "dealing with it"...that is a tactical application of technqiue....you are confusing the two.

Your decision to ski a certain line or turn and manage the forces in a certain way cause you to feel the VB in a

certain amount - same with rebound, vaulting and whatever.  I think it will help if you just stick to the forces, and what causes them....and not worry about how we manage them until later. Line=turn. Line/turn is part of what determines the forces you will have to deal with. The VB is a description of what will occur as you deal with those forces.  Wrong.  VB describes our line in 3D and the resulting forces we must deal with....nothing more....

Forces caused by gravity, momentum. Where you go, how fast you go, etc. will determine the nature of the forces you will have.  True.

I think that is the exact opposite to Rebound, which suggests the forces cause the rebound....plus the forces come from a 2D view of line...not reality.

I guess you do think rebound is a 2D view. I'm sorry if your view of rebound is 2D. Nobody ever said that. It's not only 3D, but it's actually 4D when you consider it's time element - momentum through space. What causes rebound, I'll repeat again, maybe in terms that you will allow -  You have a skier moving through space, on snow choosing a line or turn to make. Because of the laws of our physical world, there will be gravity and momentum mainly and the centripetal/centrifugal forces because of how he uses his skis and his body on the snow. These are turn forces. How he decides to manage these turn forces will determine exactly how much rebound and VB he will experience - and then have to manage that too... What is so 2D about that? Nothing.

What I wrote was is that Rebound has a 2D view of LINE.  If I got that wrong...fine....please explain how Rebound or what Rebound teaches us about 3D line, and how it is used, or what insights Rebound offers us in this regard.

It's how you see things in 3D or 2D. You like to think of rebound as a 2D line, I think of it as a 3D spatial/time relation. No different insights than with VB, huh?  Well, I and many others have explained VB and why and how it works in 3D....you have yet to offer anything with Rebound being 3D....if you have somthing....offer it.  I explained above, and numerous posts why VB is fundamentally different to rebound.

Rebound is a result of forces

VB is a cause or explanation of the forces

Quote:
Originally Posted by Cookie Bewley Hale

The VB is a description of what will occur as you deal with those forces. How is that?

That is the crux of your misunderstanding.  It is like me saying a mogul is how you deal with those forces.

In reality, a mogul is the profile of the snow surface, our line goes up over the mogul, and how we deal with this via flexing so our cm path is smooth, or jumping into the air using the mogul as a ramp, or whatever is not called "mogul", but something else.

In reality our line goes from having a direction that is inclined at 20 degrees to horizontal and back to inclined at 20 degrees.  That is the virtual bump.  Whether we decide to flex to absorb it or jump in the air off of it, is something else.

The VB is not the bump in the elevation trace of the path of the CoM, which can be adjusted by our choice of techniques; it is the bump in the elevation plot of the snow surface we travel across.

(Don't know why the quote is messed up, but the words are ok.)

Quote:
Originally Posted by Cookie Bewley Hale

In a real bump the skier feels the ground pushing back.  In a turn, or virtual bump, they feel the same thing.

Real bumps don't push. They are inate objects with no muscles...

Can a bump absorb momentum? If so, would that feel like pushing? Can snow have elastic properties? Have you ever felt a bump move?

Quote:
Originally Posted by Cookie Bewley Hale

I guess that since we are all ski instructors and since this top is about the virtual bump, wouldn't you also want to tie this discussion and resulting increase in understanding also into how to communicate and teach? Different stroke for different folks; Student centered instruction - however, even though I use quite a variety of methods and words to communicate when I teach, I still try to avoid words, images, analogies that also confuse. That is how I feel about the usefulness about the turn "virtual bump". Personal opinion and preference.

Many of us here are instructors, but not all. Being thick headed, I've personally benefitted from analogies that have confused other people present and been mind boggled by analogies that have helped others. It's quite a trick for a pro to present an analogy that may be personally useless but that would work for the student. Although I've never used "virtual bump" in a lesson, if the purpose of the analogy is to induce similar movements, there's nothing technically wrong with this teaching approach. Personally, I would not have a problem using this as a "back door approach" when presenting info through the "front door" is not working.

I'm bit too busy to post much right now but will eventually get back to this topic.

For now I thought it might be worthwhile to post a link to Ron LeMaster's take on the idea as described in "Ultimate Skiing".

L&AirC -  keep up your excellent probing effort!   Don't ever let anyone convince you something is "too complicated" for you (or anyone else) to understand.  As Bob Barnes has so frequently suggested here - question everything!

.ma

Quote:
Originally Posted by michaelA

I'm bit too busy to post much right now but will eventually get back to this topic.

For now I thought it might be worthwhile to post a link to Ron LeMaster's take on the idea as described in "Ultimate Skiing".

.ma

Bit of caution:

The link takes you to some stuff on how to deal with the VB....not on the VB itself....

Edited by Skidude72 - 6/15/10 at 9:41pm

True, I couldn't find chapter 3...

On the other hand it certainly describes the importance of the Virtual Bump and makes it clear why it's relevant to skiing.

Higher up in that text are some interesting remarks about the nature of Tip, Midbody and tail pressure found in the typical turn...    (OH! the Inequity and Horror of it all!   )

.ma

Basically we fundamentally disagree. My model does not contain a virtual bump, even though we share the same turn forces. You can believe in virtual bumps all you like, but to try and say that they are a very real, well known, accepted, fact of modern skiing is a bit inaccurate and cult-ish.

My main point is that if the VB were such a good tool to use to help with understanding and teaching, then why is there no clear, agreed upon explanation, even amongst all the LeMaster cult members? This thread has proven the confusion that surrounds the concept of the VB.

If VB is good for you, then fine. To me, it's not a good word to use.

Quote:
Originally Posted by Skidude72

Rebound is a result of forces

VB is a cause or explanation of the forces

After reading your illogic logic, I can see it's hardly possible to reason with you since you are so illogical - not to mention confused and confusing.

I think it all stems from your last comment - that rebound is a result of forces and that VB is a cause or explanation of the forces.

The turn forces existed long before the concept of a VB came along... People have been explaining and working with turn forces for centuries.

VB cannot be the cause of the forces, God is. VB cannot be an explanation of forces, they are the laws of this physical world. Physics explains the forces.

It's sort of like VB is your god.

Quote:

Well, I and many others have explained VB and why and how it works in 3D....you have yet to offer anything with Rebound being 3D....if you have somthing....offer it.  I explained above, and numerous posts why VB is fundamentally different to rebound.

So, rebound is in some 2D world and I am a stick figure? If rebound is real, it operates in a 3D world. I really fail to see how you can possibly complicate that. It seems that maybe rebound is only 2D inside your head in the way you understand it. In my 3d world, rebound exists, it is not virtual, but real - just as real as I am in this 3D world.

The fact that you think that rebound and the VB are so different illustrates your lack of understanding the interaction between the turn forces and the skier and the snow. First you wanted to say that snow didn't matter because you didn't like the word springy. Then you say that the temperature matters in the snow. Then you say you need line and slope and confuse turn forces with in some chicken and egg argument. Then you say that flexion is not going to minimize VB at all, I guess because VB Is a god and except for the laws of nature and that only line and pitch cause/create/whatever VB - no accounting for how the body moves, how fast, the snow, etc... it's only line and pitch.

Your logic there seems to be that you so much want the VB to be real, that you equate it to real bump that won't go away, but is always there... So, I guess, in your model, the VB is not so virtual after all. But then it's that "VB describes our line in 3D and the resulting forces we must deal with....nothing more...."

but then you are back to VB is the cause or explanation of the forces... so VB describes, causes, explains forces and it's nature is that of line combined with pitch, yet it's not rebound which is a result of the forces that VB causes I guess.... then it's finally that

Well, I and many others have explained VB and why and how it works in 3D....you have yet to offer anything with Rebound being 3D....if you have somthing....offer it.  I explained above, and numerous posts why VB is fundamentally different to rebound.

So I guess you are appealing to higher authorities in this mass confusion - and others are suggesting you go to the well itself and reread Ron LeMaster's, who is equally as confused in his skiing model.... in my opinion of course.

This proves the point that VB is a very very confusing matter, a great mystery, whose worshippers cannot even simply explain logically, but it's so real that it is not even virtual!

I'm sorry, but this is basically ludicrous.

Quote:
Originally Posted by therusty

Can a bump absorb momentum? If so, would that feel like pushing? Can snow have elastic properties? Have you ever felt a bump move?

I guess when someone questions the gods, people respond with outrage and confusion... What kind of a question is above? My main dislike of animating and making active the passive elements is that it misrepresents reality and hence makes it harder to understand. I would never say that a bump, snow or anything "pushes" on you. It doesn't, it can't - unless it's in an avalanche.

But to answer you questions - yes, no, yes, yes. So what? Point?

Well can we at least agree VB makes good beer?

You say your "model" doesn't include the VB and, to you, that means it's not real.  Fine.  I would remind you that your "model" is...  Well... a "model".  It is not necessarily reality or even the best "model" out there.  I'm not saying that your wrong or even that I disagree with your "model".  As a PSIA member yours is the "model" I'm most familiar with.  I do know that there are skiers that I admire, in the real world, who don't drink the kool-aid.  I've had lots of kool-aid and it tastes sweet.  It's not the only beverage that I enjoy though.  I've even enjoyed kool-aid that was spiked and that electric kool-aid can be a real eye opener...  Something to get you out of the box.  I liked LeMasters book.  PSIA likes it enough that a national officer sold me an autographed copy right in my training supervisors office.  As you say it's full of pretty pictures that illustrate his points.  Everyone likes the pictures.  Several people who I respect didn't like the text.  I haven't read all the text and I got the book close enough to the end of the season that I haven't gone on snow to convince myself if VB is "real" or not.  I think I like it.  I think I understand it.  Until I'm sure I own it, I would never use it with any student.  My point is that models are made to describe reality.  They are not reality.  They are virtual...  Just like the bump that may or may not exist.  PSIA has made me a better skier.  I use the fore-agonal move in my skiing and specifically teach it in nearly every lesson at every level.  I know a great Austrian skier who's biggest complaint with PSIA is all the unnecessary "pussy pushing" that goes on.  Another great quote from him is that "rotation is for pussies".  This is half serious joking on his part and I think its funny.  I don't see a lot of rotation or fore-agonal movement in his skiing and I think he's great, both on and off piste, skiing or snowboarding.  He is one of the most dynamic skiers I know and he (mostly) flexes in transition and extends through apex.  I don't think he, and some other great skiers, are specifically using your model.  To be fair, I also know some great skiers who happen to be PSIA examiners.  Do you think if we got them in a room that they would all agree on the same "model"?  When I look at the photos of Ligety that you posted the turns look strong and dynamic, but don't demonstrate to me the PSIA fore-agonal movement even though he is extending in transition.

Maybe PSIA is a cult or a twisted religion?

Does PSIA really stand for

"Probabably Still Inside Arguing"?

or is it
"Personal Style Isn't Allowed"?

Quote:
Originally Posted by Cookie Bewley Hale

Basically we fundamentally disagree. My model does not contain a virtual bump, even though we share the same turn forces. You can believe in virtual bumps all you like, but to try and say that they are a very real, well known, accepted, fact of modern skiing is a bit inaccurate and cult-ish.

My main point is that if the VB were such a good tool to use to help with understanding and teaching, then why is there no clear, agreed upon explanation, even amongst all the LeMaster cult members? This thread has proven the confusion that surrounds the concept of the VB.

If VB is good for you, then fine. To me, it's not a good word to use.

After reading your illogic logic, I can see it's hardly possible to reason with you since you are so illogical - not to mention confused and confusing.

I think it all stems from your last comment - that rebound is a result of forces and that VB is a cause or explanation of the forces.

The turn forces existed long before the concept of a VB came along... People have been explaining and working with turn forces for centuries.

VB cannot be the cause of the forces, God is. VB cannot be an explanation of forces, they are the laws of this physical world. Physics explains the forces.

It's sort of like VB is your god.

So, rebound is in some 2D world and I am a stick figure? If rebound is real, it operates in a 3D world. I really fail to see how you can possibly complicate that. It seems that maybe rebound is only 2D inside your head in the way you understand it. In my 3d world, rebound exists, it is not virtual, but real - just as real as I am in this 3D world.

The fact that you think that rebound and the VB are so different illustrates your lack of understanding the interaction between the turn forces and the skier and the snow. First you wanted to say that snow didn't matter because you didn't like the word springy. Then you say that the temperature matters in the snow. Then you say you need line and slope and confuse turn forces with in some chicken and egg argument. Then you say that flexion is not going to minimize VB at all, I guess because VB Is a god and except for the laws of nature and that only line and pitch cause/create/whatever VB - no accounting for how the body moves, how fast, the snow, etc... it's only line and pitch.

Your logic there seems to be that you so much want the VB to be real, that you equate it to real bump that won't go away, but is always there... So, I guess, in your model, the VB is not so virtual after all. But then it's that "VB describes our line in 3D and the resulting forces we must deal with....nothing more...."

but then you are back to VB is the cause or explanation of the forces... so VB describes, causes, explains forces and it's nature is that of line combined with pitch, yet it's not rebound which is a result of the forces that VB causes I guess.... then it's finally that

Well, I and many others have explained VB and why and how it works in 3D....you have yet to offer anything with Rebound being 3D....if you have somthing....offer it.  I explained above, and numerous posts why VB is fundamentally different to rebound.

So I guess you are appealing to higher authorities in this mass confusion - and others are suggesting you go to the well itself and reread Ron LeMaster's, who is equally as confused in his skiing model.... in my opinion of course.

This proves the point that VB is a very very confusing matter, a great mystery, whose worshippers cannot even simply explain logically, but it's so real that it is not even virtual!

I'm sorry, but this is basically ludicrous.

Oh Yea...  Cookie....  I hope to get lots of chances to ski and train with you and PJ next season.

I scouted through my video archives and found this clip. Will it add something to the discussion I dont know. Here is the clip:

Can you only feel (like) the ground pushes in "unweighting"?

I don't think anyone is saying anything different than it "feels" like the ground is pushing on you.

Originally Posted by therusty

Can a bump absorb momentum? If so, would that feel like pushing? Can snow have elastic properties? Have you ever felt a bump move?

Originally Posted by Cookie Bewley Hale

I guess when someone questions the gods, people respond with outrage and confusion... What kind of a question is above? My main dislike of animating and making active the passive elements is that it misrepresents reality and hence makes it harder to understand. I would never say that a bump, snow or anything "pushes" on you. It doesn't, it can't - unless it's in an avalanche.

But to answer you questions - yes, no, yes, yes. So what? Point?

Cookie, I think you have a mental block.

Come on!  Think man! You cannot credibly deny that while making S turns down the hill and in the apex your skis are pointing downhill and after the apex they are not pointing so much down hill.

Your model recognizes the the virtual bump, even if you don't.  The virtual bump is the change in gradient of your skis path down the slope.  That is all.

Your model incorporates this virtual bump by changing the direction of the centripetal force acting on your ski's base (and hence the net force) as you go around the turn from horizontal at the apex to having an increasingly upward direction from the apex on.  If the virtual bump were not there, your model wouldn't do that.

However, I do agree with you, even more so after skimming the above link to some of LeMaster's work,  that references to LeMaster are totally invalid as proof of anything.

Quote:
Originally Posted by Ghost
The virtual bump is the change in gradient of your skis path down the slope.  That is all.

You guys all have a serious case of off-season compulsive disorder, so I'll add my 2 cents.

When I talk about the virtual bump (which I almost never do), I'm not referring to the change in gradient that Ghost descibed.  If that were it, then I would feel it most strongly on steep terrain, when I'm turning way out of the fall line to control my speed.  Except when I'm skiiing like that, I'm usually intentionally dissipating the energy of the turn, and while I fell a pressure increase at the bottom of the turn, I don't feel a bump.  OTOH, if I'm skiing fast and aggressively on a blue groomer, I sometimes feel a bump when I go from a real high edge to flat skis at the transition.  I attribute that to the need to raise my hips to get through the transition, and the release of stored energy from the ski that goes with it.  The change in gradient through the turn isn't large enough to cause that feeling.

None if this has any value except to describe an experience.  If you have to argue about what someone's experience is, then maybe you are using wrong or confusing terms.  Trying to construct some "model" that everyone can apply (to what?) is a fool's mission.

Go outside.

BK

Quote:
Originally Posted by Bode Klammer

You guys all have a serious case of off-season compulsive disorder, so I'll add my 2 cents.

Go outside.

BK

It's all I got now that "Lost" has aired the final episode.

Great discussion.  I am very familiar with the virtual bump.  I tend to feel it when skiing steep black diamonds very fast specifically when trying to keep my speed in check.  Sometimes it gets me and it does indeed feel like a bump.

On a related point, have you ever got air and in landing felt as if you were actually landing on a platform above you rather than an area below you.  I would like to name this phenomenon the virtual platform landing...er maybe this is just me.

Quote:
Originally Posted by L&AirC

Can you only feel (like) the ground pushes in "unweighting"?

I don't think anyone is saying anything different than it "feels" like the ground is pushing on you.

Originally Posted by therusty

Can a bump absorb momentum? If so, would that feel like pushing? Can snow have elastic properties? Have you ever felt a bump move?

Originally Posted by Cookie Bewley Hale

I guess when someone questions the gods, people respond with outrage and confusion... What kind of a question is above? My main dislike of animating and making active the passive elements is that it misrepresents reality and hence makes it harder to understand. I would never say that a bump, snow or anything "pushes" on you. It doesn't, it can't - unless it's in an avalanche.

But to answer you questions - yes, no, yes, yes. So what? Point?

Point is some people think differently than other people. It's ok to speak to them in language they understand, even though that language when taken out of context is wrong or misleading. When one seeks to communicate in language that can't be taken out of context, it becomes more difficult to communicate as efficiently as possible to a single person. There are times when we need to "correct" someone when they say a bump pushes on you and there are times when we don't need to.

Another point is that being worried about literal interpretations is a slippery slope. If snow can be elastic, there are more conditions besides avalanches where snow can push on you. Sure it's no big deal. So let's not be too picky about semantics. It's really hard to have perfect models. When a literal interpretation of someone's post is obviously and fundamentally wrong, it's often more likely that  the reason is semantics, typos or brain farts instead of lack of understanding. Seek to clarify the semantics before assuming lack of understanding. If the model is not perfect focus on what it can be used for vs what it can't.

Sheesh - that's way too preachy. I'm just trying to help find a way to cut down on the rainbow colored posts before we run out of disk space.

Rusty,

You make a good point.  A friend of mine's screen saver said

"Communication isn't so much what is said, but what is heard."

Or something very close to that.  Through most of this thread, I've felt I either haven't been understood, or I need to get back to my home planet.

The best debates are the ones that produce the most learning.  Over 1300 views so it must be worth debating.

Ken

The snow pushes back when we push on it. Some may deform (think ski tacks) but if it didn't push back we would simply sink through the snow just like we would trying to stand on water. Does this mean it is mobile? Well it does creep but really isn't to relevent to the idea of the VB.

Rusty, L&AirC, Ghost and others....

As a professional, trained educator, not just in skiing - yes, to communication being about what is heard, even more than what is said.

Yes also to using comparisons and analogies to help with understanding - linking the new to the old and familiar.

Yes also to not nit-picking on terminology any more than need be for effective communication.

All agreed upon totally.

However, here is what I also think is critical, very crucial in teaching and understanding - that the analogy used, that the parable used to explain not necessarily be perfect, but at least contradict other issues that are imperative for that teaching and understanding.

Threads like this are beneficial to all in that we all go back and rethink in order to try and reexplain.

For example, take saying that snow  pushes. When I introduce some new skier to snow, I want to help them understand how it is and how to work with it. I start teaching my never-evers terrain and snow conditions from the time they first click in one ski.

One very important concept I want them to have is that they are in control of what they do. So often you hear people say that the skis did this or the snow did that.... I want it understood from the beginning that they are the operators, supplying the energy, the decisions etc. This tends to lower their fear levels and help them learn at a faster rate.

I want them to realize that the snow that the see varies and I try to help them learn more quickly how to read it. After all, it's the skis on the snow that count.

So, that is why when LeMasters and others use words that give inate object "active" power that generate thoughts of creative energy, like "push", I totally disagree.

However, of course, the snow will feel like stuff - I called it springy and I was shot down and told that snow isn't springy. Well, springy is certainly not only describes what snow can "feel" like, but it also is a lot closer to reality than having the snow "push" on you....

So, some get on my case for springy snow and I get on others cases for snow pushing.... My whole point was simply that snow does not generate or initiate any force, it is passive, but it is used and is reactive - just like a trampoline is - call it springy, call it pushing, however most people don't ever refer to trampolines as pushing back at you, but they call them springy. Why in the ski instruction circles do we want to get a bit overly creative with our word choices and end up with some confusing images in our brains?

The main point is try and understand not only each other, but also what is going on in skiing. Most people here are not scientists, most of the people writing many of the modern ski books are neither scientists or acclaimed ski instructors....(even though they may offer their works up for supposed scientific review....)  Much of skiing is really intuitive and not that complicated until we try to pretend we are "professionals" and offer up some convoluted, often inaccurate explanation. KISS is still a good thing to strive for.

This whole thread with the virtual bump being this or that or not this or not that has been a very good example of how ineffective certain choices of words in an analogy can become.

It seems that the virtual bump simply means different things to different people. For some, it's all about a way to describe some feeling some place in the turn, for others it's much more than a sensation, but it's a factual description of a force of some kind, for them, it's not even that virtual, it's real.

For sure, it's not what I would call a good example or analogy to use if it is so confusing to so many, even so many of the disciples.

However, this thread also illustrates that in skiing we do enjoy the sensations, the feelings and we do indeed talk about what we feel. We then try to understand why we feel what we do and understand the physical forces at work behind it all.

Why? Because we want to improve or learn something different. How can we do it differently or even more of the same.. Also, as ski instructors, it's all about how can we best help coach our students.

So, we create models, we test out new words, new analogies in our effort to communicate and learn. Nothing wrong with that. When you can't do something, the next best thing is sometimes to think about doing it and imagine yourself doing it. You can actually improve and learn in the process.

So, I believe that I can describe the turn forces and what I feel when I ski quite well without ever using the term a Virtual Bump. We are talking about the same physics and feelings, but I don't like calling it at a VB. I totally understand the variety of explanations of what all the VB's are out there.

I am simply saying, you do not need to use the term Virtual Bump to describe skiing.... and that the Virtual Bump concept can actually lead to quite a bit of confusion rather than clarity in describing skiing.

Whatever. Life is good and pray that the snow comes early... However, it's to Mt Hood on July 10 and 11 for me.

Tetonpwdrjunkie,

Totally agree on models and PJ's and mine isn't always exactly the standard PSIA one now.... Now, who really knows what exactly the PSIA model is, or models or whatever. Different divisions once again have quite different things going on in regards to ski technique... PJ refers to the NW as the last frontier. As we travel around and give clinics, we see all sorts of signatures from various places. We don't try to "convert" anyone, but rather simply help people improve their own skiing and teaching and have fun doing it.

As for our modeling...., we'll keep skiing until we die and we'll keep watching the Ted Ligety's of the world ski. We'll keep adapting our model as we learn more and more, to included the Ted Ligety's as well as the Junior Bounous's and the Pepi's - many different ways to skin the cat and more on the way. We even have a senior one now!

As models go, they are temporary, or should be, and they should continue to adapt to reality as either things change or we understand better. However, as humans, we seem to need to make some sort of sense out of what we see around us, hence, we model... at least that is by my understanding and there are those here who probably can find something in that concept to even disagree with.....

To me it's very sad what happened at Intermountain this winter with Ron Kipp bringing in Ron Le Master's and then Nancy and Carl peddling and selling a box of books around the division.... When we found out, we asked some board members if they had read the book yet, their response was no. So why did they think they should promote it?? PSIA is the answer I guess.

I love your Probably Still Inside Arguing... and yes, PSIA could be construed as cultish, but at least most PSIA DECL's don't follow the cult "rules" where they try to tear you down, so they can remake you and you now will be eternally grateful that they showed you the way to their "truth". We have actually encountered some ski groups that do that!  Not saying Ron LeMaster's does that, however, his materials have been used in that method of so called instruction by some people. Enough said.

Regarding flexing or extending through the transitions - you can do both - a choice of how you want to manage the turn forces. Ligety in the photos had already started extending before transition. Transition didn't change that - he went through it still extending/reaching/moving into the next turn.

The main point I think is to understand that flexion/extension, foot-to-foot weight transfer, progressive edging/releasing, continual and progressive guiding/resisting/steering all have different dials and occur at different rates and change their "directions" at different points in the turn, but they all work together to achieve whatever purpose you have for the skis on the snow - where you want to go with your skis, how much edge, shape of turn, speed, etc...Skis on snow is what we all love about skiing! So much for models huh, we need more snow.

Quote:
Originally Posted by tetonpwdrjunkie

You say your "model" doesn't include the VB and, to you, that means it's not real.  Fine.  I would remind you that your "model" is...  Well... a "model".  It is not necessarily reality or even the best "model" out there.  I'm not saying that your wrong or even that I disagree with your "model".  As a PSIA member yours is the "model" I'm most familiar with.  I do know that there are skiers that I admire, in the real world, who don't drink the kool-aid.  I've had lots of kool-aid and it tastes sweet.  It's not the only beverage that I enjoy though.  I've even enjoyed kool-aid that was spiked and that electric kool-aid can be a real eye opener...  Something to get you out of the box.  I liked LeMasters book.  PSIA likes it enough that a national officer sold me an autographed copy right in my training supervisors office.  As you say it's full of pretty pictures that illustrate his points.  Everyone likes the pictures.  Several people who I respect didn't like the text.  I haven't read all the text and I got the book close enough to the end of the season that I haven't gone on snow to convince myself if VB is "real" or not.  I think I like it.  I think I understand it.  Until I'm sure I own it, I would never use it with any student.  My point is that models are made to describe reality.  They are not reality.  They are virtual...  Just like the bump that may or may not exist.  PSIA has made me a better skier.  I use the fore-agonal move in my skiing and specifically teach it in nearly every lesson at every level.  I know a great Austrian skier who's biggest complaint with PSIA is all the unnecessary "pussy pushing" that goes on.  Another great quote from him is that "rotation is for pussies".  This is half serious joking on his part and I think its funny.  I don't see a lot of rotation or fore-agonal movement in his skiing and I think he's great, both on and off piste, skiing or snowboarding.  He is one of the most dynamic skiers I know and he (mostly) flexes in transition and extends through apex.  I don't think he, and some other great skiers, are specifically using your model.  To be fair, I also know some great skiers who happen to be PSIA examiners.  Do you think if we got them in a room that they would all agree on the same "model"?  When I look at the photos of Ligety that you posted the turns look strong and dynamic, but don't demonstrate to me the PSIA fore-agonal movement even though he is extending in transition.

Maybe PSIA is a cult or a twisted religion?

Does PSIA really stand for

"Probabably Still Inside Arguing"?

or is it
"Personal Style Isn't Allowed"?

Quote:
Originally Posted by justanotherskipro

The snow pushes back when we push on it. Some may deform (think ski tacks) but if it didn't push back we would simply sink through the snow just like we would trying to stand on water. Does this mean it is mobile? Well it does creep but really isn't to relevent to the idea of the VB.

Briefly, snow is very relevant to the VB concept. It's a factor that must be added in. Different snow allows for different VB effects.

Read above again about my dislike of the word "push" when describing snow - springy-yes, soft-yes, hard-yes, dead-yes, push-no, sticky-yes, pull-no, loud-yes.... Just the idea that it puts in your head is what I disagree with, not the fact that snow is reactive to what you do with it.

Cookie,

I've always viewed all information as useful.  It could be correct, unproven or even incorrect, but I always felt that somewhere, I'll get use out of knowing it.

I believe it was Edison that said; "You want results!  I know 10,000 things that don't work."  That's useful!

I may never discuss VB, Rebound, Vaulting or even Blending with a student.  Should it come up I'll be much better prepared than I was before this thread started and I thank all the participants for that.

All,

I'm starting to think with regards to VB, this thread has served its purpose and everything has been covered from several different angles .  Any member of Epic can read through 5 pages of great information from all sides of the concept and make their own decision.

My wife has been giving me the "stink eye" lately because I'm spennding so much time on the computer and I still want to get to discussing Vaulting (in a new thread), but I'm already spending too much time on the computer in this conversation.

See your there.

I definitely enjoyed this one,

Ken

Cookie,

You know Newton's Third Law of Motion? It explains the push-back from the snow. Even kids can get this concept!

(From Physics 4Kids):

Quote:

# Third Law

The third law says that for every action (force) there is an equal and opposite reaction (force). Forces are found in pairs. Think about the time you sit in a chair. Your body exerts a force downward and that chair needs to exert an equal force upward or the chair will collapse. It's an issue of symmetry. Acting forces encounter other forces in the opposite direction. There's also the example of shooting a cannonball. When the cannonball is fired through the air (by the explosion), the cannon is pushed backward. The force pushing the ball out was equal to the force pushing the cannon back, but the effect on the cannon is less noticeable because it has a much larger mass. That example is similar to the kick when a gun fires a bullet forward.

Only have a few minutes, so this will be quick - be back later on tonight.

Please read more carefully - nothing about the laws of physics here, only about choice of words to us to describe snow......

Quote:
Originally Posted by nolo

Cookie,

You know Newton's Third Law of Motion? It explains the push-back from the snow. Even kids can get this concept!

(From Physics 4Kids):

Nolo, Please read what I said. Nothing about denying Newton's  Third Law of Motion - just that I don't like to animate the snow and say it pushes!!!!! It's not active and alive, but it reacts when acted upon! That is all I've been saying. The snow doesn't push on you, you push on it and it is reactive depending on the snow conditions!

I'm having a bit of difficulty understanding the standard here. I first called snow springy and was called on the carpet for that one... Then I say I don't like to say that snow pushes, not use the word "push" because of what it implies, which is life the ability to create and generate energy. So springy is not allowed here, but to say the snow pushes is? What the heck? Where is the standard and where is the thinking here? Circular?

Matter of fact, I don't even think describing snow as pushing is a good analogy at all because it doesn't even feel like something pushing. It feels more like it's ranging any where a very grippable surface that holds to one that you can almost feel like you are bouncing off of to one that breaks away to so hard you can only slide!!! It never ever feels like it is pushing on you - it only feels like it is reacting to whatever forces you put on it!!!! It's snow and it isn't alive. I doesn't have muscles and it can't actively push!

Okay, I've repeated and explained the push issue in 20,000000000 ways now. Done with it. It does't push.

If a snowball comes flying from behind and whacks you in the back of the head... is it pushing on you?

If you're wearing a blindfold and skiing down a bump field, will you perceive the snow suddenly (and unexpectedly) pushing up at you?

If a "scientist" decides to mathematically model the experience of that same blindfolded skier from their Internal Frame of Reference, could they mathematically model the impact with each bump as though it were coming at, and pushing on the skier?

.ma

What is it with this pushing? I really don't care what you believe and how you want to refer to the snow. In my book, it doesn't push and never will push. When I'm hit by a snowball, I am hit by a snowball... It didn't push me. If you come up to me and push me, you push me.

I don't believe in dragons under my bed either or snow snakes pushing up at me as I ski down the bumps.... I go over and around bumps, and never once has one reached out and either grabbed me or pushed me.

I don't agree that a pushing frame of reference is helpful either for understanding or teaching. So, don't try to keep pushing it on me. I disagree and that is all I ever said. You can be pushed around by the snow all  you want. I don't like the concept.

Comprenez vous?

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