How to describe

[OdderMensch]

this is from another thread and is nominally about the martial arts, and the concept of 'chi'

What path does it follow? As i understand it (and my knowlege is indeed minimal) every action has an equal and opposite reaction,
There is no path. Force is the capacity to do work or damage.

Ok, as i am taught. If you take a whip, and move it just right, the result is that the tip breaks the sound barrier and produces a very small sonic boom heard as a loud CRACK! Now if you move just the tip, it will not make the same noise, so where does the tip get the energy to break the sound barrier? It gets it from the small movement of your wrist, but your wrist alone cannot cause the whip to move, it take coordination with your elbow, your waist your knees, even your ankles to produce tha maximum amount of energy (used as speed) at the tip of the whip. Is it incorrect to say the "energy moved from my wrst, thru the whip into the tip"?

So how do you descibe the 'energy moveing from my wrist to the tip of the whip"?

[Soapy Sam]

I would describe it as kinetic energy, supplied by my muscles, using well established metabolic principles to derive chemical energy from food, which came from solar energy.
If any other route is involved, I don't know about it.

[OdderMensch]

but how does the 'energy' get from my wrist to the tip of the whip?

(I know how we produce kinetic and thermal energy from food, it's why the robots keep us in the power plant.....:D sorry, I go to a Matrix Reloaded prescreening in a few hours, the one perk of a job at a theater)

[fishbob]

The whip tapers. You throw a loop in the whip at the blunt end, at a given speed. As the loop travels along the whip, there is less and less mass of whip material, but momentum is conserved, so the speed of the loop increases.

[Dancing David]

Chi or ki is a lot like the Force in star Wrs, I am not sure that it is transmitted through the whip.

According to Deng Ming Dao chi is generated from gi(sex power) through meditation, others think it is part of life.

Peace

[OdderMensch]

The whip tapers. You throw a loop in the whip at the blunt end, at a given speed. As the loop travels along the whip, there is less and less mass of whip material, but momentum is conserved, so the speed of the loop increases.

The tapering maximizes the resultent speed at the tip, but what do you desricibe the looping motion as?

also, the Chinese have a weapon called a chain whip or 9-section staff, it is a series of 2-4 inch metal rods conected by chain links and is used with a simmilar whiping action. The tip doesn't (to my knowledge) break the sound barier, but the tip can cause a good bit of damage. Is it possible for the looping motion to increase momentum? and if so what is that process called?

[Dancing David]

I am not a brainiac but I think it would be conservation of angualr/non-angular momentum there is also the lever action of the arm and whip.

Peace

[daver]

Thought experiment, since i'm too inept to do this for real.

Say you try to build a mechanical whip cracker--a motorized arm that flicks up and down and causes an attached whip to crack.

If you could build it, it would imply that (1) you have a mechanical chi generator, or (2) chi does not need to be invoked to explain whip cracks.

If you couldn't build it, it would imply that (3) you are mechanically inept, or (4) chi is necessary to crack whips.

I would bet on (2) or (3).

[Dymanic]

The tapering maximizes the resultent speed at the tip, but what do you desricibe the looping motion as?
It's a wave.

It's just like the way an ocean wave's energy becomes more concentrated when it enters the shallower water near shore.

[WildCat]

From here: (http://www.sciam.com/article.cfm?articleID=00088B33-8E92-1CEE-93F6809EC5880000&pageNumber=1&catID=1)
Previous whip work (one of just three papers on the subject in the past century) had resulted in the puzzling observation that the sonic boom occurs when the tip of the whip is traveling at about twice the speed of sound. But if the tip were truly the cause of the crack, why wasn't the sound heard earlier, when the tip first reached the speed of sound? Goriely and McMillen's calculations have revealed the answer. "The crack of a whip comes from a loop traveling along the whip, gaining speed until it reaches the speed of sound and creates a sonic boom," Goriely says. He notes that even though some parts of the whip travel at greater speeds, "it is the loop itself that generates the sonic boom."

[QuarkChild]

I'm not sure of whom you meant to refer to in the phrase "How do you describe...," but I've heard physicists use the phrase "momentum transfer" to describe such a process. I would say, "the kinetic energy is transferred from one end of the whip to the other."
You might be tempted to graph the position of the wavepacket (what you are calling a loop?) as a function of time, and point the graph and say, "that's the path of the energy," but I don't think a physicist would ever say it that way; it seems too sloppy.

The wavepacket carries energy (and momentum) along a path.
That's as far as I'll go.

[fishbob]

but what do you desricibe the looping motion as? As Dynamic said, "It's a wave"

If you reverse the whip and hold the thin end, the other end will not crack. But, you will probably bop yourself in the back of the head with the handle.

[Soapy Sam]

Fishbob said-
"If you reverse the whip and hold the thin end, the other end will not crack. But, you will probably bop yourself in the back of the head with the handle."
Now explain THAT in terms of "Chi"!

I'm a bit baffled about "chi". It seems to mean all things to all people, from "centre of balance", through "momentum" to "mystical life energy". I never saw any need for it in explanations of martial arts. Just hitting someone hard is sufficient reason for him to go "Ouch!", without boring him to death with oriental mysticism too.

On the whip question. Ever see a line of skaters, hand in hand, where one end act as a pivot to swing the chain of people around? The poor devil on the outer end can be going at one heck of a clip. It's just the slingshot effect; conservation of angular momentum, like gravitational billiards around Jupiter and using an Atlatl to chuck a spear farther. No magic. At no time do my hands leave my wrists.

[OdderMensch]

Originally posted by Soapy Sam
I'm a bit baffled about "chi". It seems to mean all things to all people, from "centre of balance", through "momentum" to "mystical life energy". I never saw any need for it in explanations of martial arts. Just hitting someone hard is sufficient reason for him to go "Ouch!", without boring him to death with oriental mysticism too.

I have three reasons to study 'chi'
first is the same reason I had to study christian imagerey in order to better apreciate medevil art, and the Renisance art that followed it. Second is that a better understanding of the idea allows me to seperate the knowledge from the supersition. Finally, it helps me hit harder, so people go "Ouch!" more :D

On the whip question. Ever see a line of skaters, hand in hand, where one end act as a pivot to swing the chain of people around? The poor devil on the outer end can be going at one heck of a clip. It's just the slingshot effect; conservation of angular momentum, like gravitational billiards around Jupiter and using an Atlatl to chuck a spear farther. No magic. At no time do my hands leave my wrists.

Yup no magic, but it doesn't seem any more precise to use the 'slingshot' analogy than the 'qi flow' analogy. Getting into idea's about conservation of angular momentum, the transfer of kinetic energy and the graphing of effect over time is why I started this thread, and I thank everyone for helping me along my way.

3

[c0rbin]

I think one could build a machine to mimic the motion of the arm and wrist, attach a whip to it and achieve the same results.

Does then the machine have chi??

[peptoabysmal]

You are speaking of yang chi, the "male" outward aggressive type of chi. Supposedly, if you get good enough with the yin chi, the "female" inward passive type if chi, you can pick up small objects at the end of a staff.

I was a martial artist for many years, and studied under a master who was from the "old country" and did things the "old way". It wasn't quite as americanized as many studios are now.

While I also have a tendency to explain the forces involved as pure physics, I can honestly say that I've done things that I didn't know how I did it, such as levelling an opponent with what felt like to me little more than a tap.

One thing I can be sure of is that a person can do some amazing things when their mind, body and will are all concentrated on the same effort.

If you are studying chi in martial arts, the one hint I'll give you is that your breathing technique is paramount to success.

[BillyJoe]

If Chi can be said to exist it, of course, does not exist as a force but rather as a psychological mechanism.

It's no more a force than "visualisation". Haven't you ever visualised that basketball looping up, over and down through the hoop just before you actually make it do that for real?
Maybe we can call it Chi.
Maybe we just call it "visualisation". ;)

regards,
BillyJoe

[Dancing David]

ki is the force of a mindful , coordinated motion, practised to the point of non thinking. I am two hundred and forty pounds and have been thrown over forty feet by women massing half of that.
It is a cool thing whatever it is.

Peace

[daver]

Originally posted by Dancing David
ki is the force of a mindful , coordinated motion, practised to the point of non thinking. I am two hundred and forty pounds and have been thrown over forty feet by women massing half of that.

Is that measured from the point of the throw to the first bounce or to when you stopped moving?

[Dancing David]

Originally posted by daver

Is that measured from the point of the throw to the first bounce or to when you stopped moving?

From the point my foot left the floor until my hand touched it.(There is a trick here , I was practising aikido, I charged her at running speed and she rerouted my momentum, so the lateral distance is not suprising.)

Peace

[OdderMensch]

Originally posted by BillyJoe
If Chi can be said to exist it, of course, does not exist as a force but rather as a psychological mechanism.

It's no more a force than "visualisation". Haven't you ever visualised that basketball looping up, over and down through the hoop just before you actually make it do that for real?
Maybe we can call it Chi.
Maybe we just call it "visualisation". ;)

regards,
BillyJoe

As I stated in the other thread in banter "penn & teller - selfhelpless" I don't think it is possible to apply a single word definition to the concept of chi.

Also i am totally lost on your example, as I have never gotten a ball to go thru that darn hoop :D

[daver]

Originally posted by Dancing David


From the point my foot left the floor until my hand touched it.(There is a trick here , I was practising aikido, I charged her at running speed and she rerouted my momentum, so the lateral distance is not suprising.)

Peace

If i were to kick a ball 40 feet it would leave my foot at ~25 mph and be maybe 10 feet off the ground at its highest point. Obviously the situation is more complicated than that. Track & field record for the long jump is just short of 30 feet, which makes a 40 foot throw pretty remarkable.

[garys_2k]

Perhaps one of the ladies could suggest that sometimes guys exaggerate distance, as in say, claiming that an object about five inches long is close to nine inches. Same thing may be happening here with this throw distance... ;)

[CurtC]

OdderMensch wrote:
What path does it follow? As i understand it (and my knowlege is indeed minimal) every action has an equal and opposite reaction,
There is no path. Force is the capacity to do work or damage.Ugh. It's actually energy that's defined as the capacity to do work. I've never seen anyone get confused about force, since it's so intuitive. It's usally energy that the clueless latch on to.

[jj]

The answer to your original question is that you set up a travelling wave down the whip, one that goes through a rapid discontinuity when it hits a boundary condition.

I realize that's not incredibly satisfying.

[Dancing David]

Originally posted by daver


If i were to kick a ball 40 feet it would leave my foot at ~25 mph and be maybe 10 feet off the ground at its highest point. Obviously the situation is more complicated than that. Track & field record for the long jump is just short of 30 feet, which makes a 40 foot throw pretty remarkable.

I agree I told my fellow students that she would have had to throw me at like thirty miles an hour for me to go forty feet, they measured it. I said I bet it was more like twenty five, forty they said.

My manhood is only average, but my submission to peer pressure is large!

Peace

[c0rbin]

I realize that's not incredibly satisfying.

This answer satisfies me greatly.

[RedCoat]

Originally posted by Dancing David
ki is the force of a mindful , coordinated motion, practised to the point of non thinking. I am two hundred and forty pounds and have been thrown over forty feet by women massing half of that.
It is a cool thing whatever it is.

Peace


Are you sure your were thrown "over 40 feet"? Forty feet is a long, long way to be airborn...analogous to a serious motorcycle accident or a fall from a substantial height. Were you injured in any way?

-RedCoat