Contact Point v Contact Patch

ENGLISH! said:
Best AnswerAsker's Choice

appleton_strings answered 7 years ago
An edge can be defined as a curve or line where the limiting tangent planes coming from different directions do not tend towards the same limit. For example, the flat part of a cylinder is ALWAYS at right angles to a tangent plane anywhere on the curved part, so the cylinder has an "edge" where the two portions meet.

At any point on a sphere, the tangent planes coming in from ANY direction all have the same limit - so a sphere has no edges. For this reason, a sphere is called a "manifold without boundary" (and cylinders and cones, etc, are called "manifolds WITH boundary")

e·qua·tor (ĭ-kwā′tər)
n.
1.
a. The imaginary great circle around the earth's surface, equidistant from the poles and perpendicular to the earth's axis of rotation. It divides the earth into the Northern Hemisphere and the Southern Hemisphere.
b. A similar great circle drawn on the surface of a celestial body at right angles to the axis of rotation.
2. The celestial equator.
3. A circle that divides a sphere or other surface into congruent parts.
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When you look at a sphere, you only see 180deg...therefore, from any angle, you perceive a circle or disc. Circles have edges and you base your alignment on information provided by circles, not spheres.

Seeing pool balls as spheres is step#1 to not progressing as a player.
 
cookie man said:
You are so late to the party.
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Not really. It was just a link to why duckie gets this idea about a contact patch.

duckie mentioned the Arrow in previous threads, referencing his contact patch.

I don't think It's unreasonable, but there's no way to consistently aim at a patch.

When he says the pros don't know more but are just consistent, he's full of BS.

The Arrow that Babe Cranfield made is for begginers without aiming knowledge.

.
 
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Ralph Kramden said:
Not really. It was just a link to why duckie gets this idea about a contact patch.

duckie mentioned the Arrow in previous threads, referencing his contact patch.

I don't think It's unreasonable, but there's no way to consistently aim at a patch.

When he says the pros don't know more but are just consistent, he's full of BS.

The Arrow that Babe Cranfield made is for begginers without aiming knowledge.

.
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Best post of thread
 
SpiderWebComm said:
When you look at a sphere, you only see 180deg...therefore, from any angle, you perceive a circle or disc. Circles have edges and you base your alignment on information provided by circles, not spheres.

Seeing pool balls as spheres is step#1 to not progressing as a player.
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Dave,

mhort asked the question & I was just trying to provide an answer without getting into an argument. I've tried to get Duckie/ Greg to conceded to some vernacular for the sake of discussion.

I'm not sure I would totally agree with your statements as there is more than one way to skin a cat. You've made a rather wide blanket statement there.

I & I think Duckie/Greg & others know that we have to get the CB 'on the side' of the object ball in order to get a cut angle.

Perhaps your statements are more conducive for progressing within certain other systems besides Ghost Ball.

The goal for any system or method is to get the cue ball into the ghost ball position. There is more than one way to do that.

I quickly went from Ghost Ball to the equal & opposite fractional overlap method that I thought I had invented at age 13. But I still SAW the object ball & cue ball as spheres to determine what overlap sends the ball where. I think Greg & many others do too.

Since I have used the equal & opposite fractional overlap method, I can certainly understand the concept of imagining a 2D envisioned representation of the object ball standing on it's edge & rotating to face one's self as one moves from side to side.

However I've found it better to have a mind set that the balls are more like flat discs sitting with their fullness on the table much like CJ Wiley has referenced in some of his DVDs & some of his posts here on AZB.

Dave, I'm not looking to get into ANY argument. I was & am just trying to clarify some things so as to have some common ground of understanding.

Perhaps the largest problem in the world is miscommunication or a lack of communication.

We certainly have much of that here on AZB.

Best Wishes to You & ALL,
Rick
 
Ralph Kramden said:
Not really. It was just a link to why duckie gets this idea about a contact patch.

duckie mentioned the Arrow in previous threads, referencing his contact patch.

I don't think It's unreasonable, but there's no way to consistently aim at a patch.

When he says the pros don't know more but are just consistent, he's full of BS.

The Arrow that Babe Cranfield made is for begginers without aiming knowledge.

.
Click to expand...

I wouldn't say duckie is full of BS by saying the pros are more consistent. Lots of aiming systems depend on the quality of your stroke. Pros have much better strokes and can consistently shoot the cue ball down the desired path. Mark Wilson's book goes into depth on this subject. The pros don't have some secret aiming system.

Snooker players are better shotmakers because they have stronger fundamentals. They laugh at us because we try all of these different systems instead of spending more time on delivering the cue repeatably to an exact spot on the cue ball.

Pool is not hard because we are unable to aim. It is hard to get the cue ball within millimeters of your target over and over while playing shape.
 
nine_ball6970 said:
I wouldn't say duckie is full of BS by saying the pros are more consistent. Lots of aiming systems depend on the quality of your stroke. Pros have much better strokes and can consistently shoot the cue ball down the desired path. Mark Wilson's book goes into depth on this subject. The pros don't have some secret aiming system.

Snooker players are better shotmakers because they have stronger fundamentals. They laugh at us because we try all of these different systems instead of spending more time on delivering the cue repeatably to an exact spot on the cue ball.

Pool is not hard because we are unable to aim. It is hard to get the cue ball within millimeters of your target over and over while playing shape.
Click to expand...

i had to emphasize your statement because i agree 100%....:thumbup:
 
Isn't that a measure of consistency?


nine_ball6970 said:
I wouldn't say duckie is full of BS by saying the pros are more consistent. Lots of aiming systems depend on the quality of your stroke. Pros have much better strokes and can consistently shoot the cue ball down the desired path. Mark Wilson's book goes into depth on this subject. The pros don't have some secret aiming system.

Snooker players are better shotmakers because they have stronger fundamentals. They laugh at us because we try all of these different systems instead of spending more time on delivering the cue repeatably to an exact spot on the cue ball.

Pool is not hard because we are unable to aim. It is hard to get the cue ball within millimeters of your target over and over while playing shape.
Click to expand...
 
nine_ball6970 said:
I wouldn't say duckie is full of BS by saying the pros are more consistent. Lots of aiming systems depend on the quality of your stroke. Pros have much better strokes and can consistently shoot the cue ball down the desired path. Mark Wilson's book goes into depth on this subject. The pros don't have some secret aiming system.

Snooker players are better shotmakers because they have stronger fundamentals. Thiey laugh at us because we try all of these different systems instead of spending more time on delivering the cue repeatably to an exact spot on the cue ball.

Pool is not hard because we are unable to aim. It is hard to get the cue ball within millimeters of your target over and over while playing shape.
Click to expand...

I wasn't referring to the "more consistent" part of his statements.... I agree that the pros are.
The statement made was.. the pros don't really know more, they are just more consistent.

I meant to say that he's full of BS if he thinks the pros don't know more than duckie.... Aflac!
.
 
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ENGLISH! said:
Dave,

mhort asked the question & I was just trying to provide an answer without getting into an argument. I've tried to get Duckie/ Greg to conceded to some vernacular for the sake of discussion.

I'm not sure I would totally agree with your statements as there is more than one way to skin a cat. You've made a rather wide blanket statement there.

I & I think Duckie/Greg & others know that we have to get the CB 'on the side' of the object ball in order to get a cut angle.

Perhaps your statements are more conducive for progressing within certain other systems besides Ghost Ball.

The goal for any system or method is to get the cue ball into the ghost ball position. There is more than one way to do that.

I quickly went from Ghost Ball to the equal & opposite fractional overlap method that I thought I had invented at age 13. But I still SAW the object ball & cue ball as spheres to determine what overlap sends the ball where. I think Greg & many others do too.

Since I have used the equal & opposite fractional overlap method, I can certainly understand the concept of imagining a 2D envisioned representation of the object ball standing on it's edge & rotating to face one's self as one moves from side to side.

However I've found it better to have a mind set that the balls are more like flat discs sitting with their fullness on the table much like CJ Wiley has referenced in some of his DVDs & some of his posts here on AZB.

Dave, I'm not looking to get into ANY argument. I was & am just trying to clarify some things so as to have some common ground of understanding.

Perhaps the largest problem in the world is miscommunication or a lack of communication.

We certainly have much of that here on AZB.

Best Wishes to You & ALL,
Rick
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All balls have visual edges: top, bottom, left and right. The fact that you guys state otherwise is laughable. Sorry.
 
SpiderWebComm said:
All balls have visual edges: top, bottom, left and right. The fact that you guys state otherwise is laughable. Sorry.
Click to expand...

Dave,

I can agree with that. You said 'visual edge' & I understand what you mean.

However since spheres REALLY do NOT have edges (please see the 'definition' from the earlier post), one can NOT actually see them objectively. One can envision or imagine or interpret or visualize what would be the edge if the ball were not a sphere but a flat circle instead.

Hence a 'visual edge'. I understand what you mean as I think almost everyone does.

But... please keep in mind that since the ball is really a sphere & not a 2D circle that if one is looking straight at the 'edge' from a certain position relative to a line, one would not see the same 'edge' point relative to a different line of reference... where one would see the same edge point IF the 'ball' were a 2D circle.

I think Duckie/Greg takes it to the point that since a ball or sphere does NOT actually, really, have an edge (please see the 'definition' from the earlier post), then how can one objectively visually see what does NOT actually exist, like a ghost ball.

Perhaps he has been 'beaten' into taking that stand, because of all the 'jokes' about not being able to actually see a Ghost Ball. I don't actually know.

Best,
Rick
 
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ENGLISH! said:
Dave,

I can agree with that. You said 'visual edge' & I understand what you mean.

However since spheres REALLY do NOT have edges (please see the 'definition' from the earlier post), one can NOT actually see them objectively. One can envision or imagine or interpret or visualize what would be the edge if the ball were not a sphere but a flat circle instead.

Hence a 'visual edge'. I understand what you mean as I think almost everyone does.

But... please keep in mind that since the ball is really a sphere & not a 2D circle that if one is looking straight at the 'edge' from a certain position relative to a line, one would not see the same 'edge' point relative to a different line of reference... where one would see the same edge point IF the 'ball' were a 2D circle.

I think Duckie/Greg takes it to the point that since a ball or sphere does NOT actually, really, have an edge (please see the 'definition' from the earlier post), then how can one objectively visually see what does NOT actually exist, like a ghost ball.

Perhaps he has been 'beaten' into taking that stand, because of all the 'jokes' about not being able to actually see a Ghost Ball. I don't actually know.

Best,
Rick
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Based on a fixed eye position, how can you cay those 4 points aren't 100% objective? Wow.
 
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SpiderWebComm said:
Based on a fixed eye position, how can you cay those 4 points aren't 100% objective? Wow.
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You've just put a parameter on it that would make it seem objective but it is reality not.

If we stand side by side we will NOT see the same 'edge' point on the ball. We will see different subjective 'edge' points.

If we stand side by side & look at the right upper corner of a light switch we will both see the same objective right upper corner of the light switch.

That right upper corner of the light switch is an objective point that can be seen from all different subjective vantages.
 
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ENGLISH! said:
You've just put a parameter on it that would make it seem objective but it is reality not.

If we stand side by side we will NOT see the same 'edge' point on the ball. We will see different subjective 'edge' points.

If we stand side by side & look at the right upper corner of a light switch we will see the same objective right upper corner of the light switch.

That right upper corner of the light switch is an object point that can be seen from all different subjective vantages.
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Whatever you say, buddy. G'luck with your game.
 
ENGLISH! said:
You've just put a parameter on it that would make it seem objective but it is reality not.

If we stand side by side we will NOT see the same 'edge' point on the ball. We will see different subjective 'edge' points.

If we stand side by side & look at the right upper corner of a light switch we will see the same objective right upper corner of the light switch.

That right upper corner of the light switch is an object point that can be seen from all different subjective vantages.
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Standing side by side we'll see different parts of a ball... but it's a round ball to both people looking at it.
We certainly see different edge points if the ball is rolling. We'll both see the same edges over and over.

The only edges that matter are the ones on the shot line of the CB.. and when it's rolling into the pocket.
.
 
Ralph Kramden said:
Standing side by side we'll see different parts of a ball... Yes the 'edge' of the ball will be different for two individuals standing side by side & hence the visual 'edge' of a round sphere is not objective. but it's a round ball to both people looking at it. Yes, obviously.
We certainly see different edge points if the ball is rolling. Still or rolling makes no difference. We'll both see the same edges over and over. No, two individuals standing side by side will not see the same 'edges'.

The only edges that matter are the ones on the shot line of the CB.. and when it's rolling into the pocket. I have no idea what you are trying to say here.
.
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Sorry for the inserts, but to me, that is not a very coherent post.
 
ENGLISH! said:
Sorry for the inserts, but to me, that is not a very coherent post.
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Try this for coherent. Both the CB and 9 ball have edges. We'll both see
the CB and the 9 ball edges from completely different points.

From your view you think I'm not in line. From my view the shot looks OK.
I hit CB into the 9 and you watch the 9 ball roll into the pocket.

.
 
Ralph Kramden said:
Try this for coherent. Both the CB and 9 ball have edges. We'll both see
the CB and the 9 ball edges from completely different points.

From your view you think I'm not in line. From my view the shot looks OK.
I hit CB into the 9 and you watch the 9 ball roll into the pocket.

.
Click to expand...

Okay, that's a 'nice' hypothetical, but what's your point?
 
Speaking of being on point. In the context of pool, I think we all know exactly what we are referring to when we say edges and centers of balls. From a specific fixed eye position, we are all referring to the same visual edges and centers. Arguing over what the dictionary definition of an edge is in the context of 3d spheres is, to say, quite pointless.
 
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