transmitting side??

[lkomarci]

Ok now I'd like to get clear with this, what is this all about?? Today was the second time that a player told me there's such thing as transmitting side from the cueball to an object ball. He was like "oook so if I the cueball spins this way the object ball should start spinning that way", and he's looking at the angles and stuff, I was like [What the..??]

So let me put some facts on the table, when a spin is applied to the cueball, there is obviously a lot of friction because of the tip material, chalk and the amount of surface that gets into contact with the cueball.

When the cueball collides with an object ball, the collision surface is tiny, and the material is smooth.

So how on Earth can sides be transmitted with conditions like those??

[DandyA]

Ok now I'd like to get clear with this, what is this all about?? Today was the second time that a player told me there's such thing as transmitting side from the cueball to an object ball. He was like "oook so if I the cueball spins this way the object ball should start spinning that way", and he's looking at the angles and stuff, I was like [What the..??]

So let me put some facts on the table, when a spin is applied to the cueball, there is obviously a lot of friction because of the tip material, chalk and the amount of surface that gets into contact with the cueball.

When the cueball collides with an object ball, the collision surface is tiny, and the material is smooth.

So how on Earth can sides be transmitted with conditions like those??

some people say you can, some say you can't, some say it depends on the type of ball (phenolic, crystallite etc) ... but in my view, anyone logical would say even if you can, the effect is miniscule for the reason you mentioned ... it's hard enough getting spin onto the cue ball using a nice soft grippy cue and tip - so cue ball to object ball (two smooth hard surfaces) is nigh-on impossible ...

however, what you can definitely do is "throw" the object ball off it's normal line if you put side on the cue ball ... this is not the same as transferring side ... as the cue ball and object ball are in (very brief) contact, if the cue ball is spinning, it throws the object ball slightly to the right if the cue ball has left hand side or of course, vice versa ...

there are many vids demonstrating this ... off the top of my head, one of the clearest examples is towards the end of Jack Karnehm's coaching videos where he explains the "trick" behind nursery cannons in billiards ...

on a different but similar subject, the balls (either cue or object) do definitely seem to pick-up side as they bounce off the cushions - anyone got a really good guide to this?

[pearce]

How do you explain the Minnesota Fats video with Waylon Jennings admittedly with 9 Ball Pool Balls where he hits half way between bottom and side pocket with cue ball about a foot from the object ball straight into the cushion and it comes off and into the middle pocket. He then plays the same shot and it comes off and into the bottom corner pocket. He does this several times and then says "Now tell me there's no such thing as imparted side".

[cueman]

I believe you can do it but I'm not up with the physics side to be able to give it a description.

[BarryH]

I don't know the answer, but would agree that any transferred spin would be minimal generally.

Maybe what's being referred to is the effect you can get where the angle the object ball goes in appears to be altered by the side the shot is played with. In my experience there are some shots where the natural angle for potting a ball is sometimes blocked, or very nearly blocked by another ball very close to the object ball. By applying side in the opposite direction to the way you want to increase the angle of travel of the object ball, you can make these balls pottable, or more easily makeable. I'm not sure that this is tranferring side, or just altering the path of the cueball, but it often seems that the object ball's direction is altered with respect to the point of contact with the cue ball. My feeling is that you can sometimes "squeeze" a shot with some side that is otherwise not on, and that given the proximity of the adjacent ball the effect can't be fully explained by a curved cueball path as there isn't enough room.

[lkomarci]

I guess it might depend on the ball material, however I'm still searching youtube for those high-speed camera videos.
If there's no such videos then they definately should be made to sort this out. But I still believe there's no way that side can be transmitted in such amount that would effect the object ball. The friction should be as big as when you hit the cueball just a bit off-centre, so I just don't see this happening.

[BarryH]

Maybe you could experiment with a set of pool balls - you should be able to see any substantial spin imparted.

[tallguy]

A similiar thread with links to videos.

http://www.thesnookerforum.com/board...ad.php?t=14107

[eaoin11]

If you trawl through Steve Davis's old coaching vids on youtube he says that side doesn't transfer. When he demonstrates with a striped ball he describes the ensuing effect as 'wobble', not side.

I'm not entirely convinced though, and the video is old. He might say something else these days...

[poolqjunkie]

Actually Steve Davis did say something else later.

Where do you think the rotational energy goes if they do not get transmitted upon impact to the object ball? Does it all get lost in friction, sound, and so forth upon impact?

If not, then they must have gone somewhere. So, where does it go?

When you hit a ball with spin to the cushion, the cushion absorbs a lot of the rotational energy as it is more elastic then the ball, but still side energy is not totally lost. The rotational energy was partly transferred to the cushion causing the ball to go wider/narrower. The result is quite significant. Why do you think this transfer of rotational energy will not happen when a ball hits another ball?

Even though the surfaces between two balls seem quite smooth but there are friction acting upon impact. If there was no friction, how could you draw a ball back? When the two balls collide, the bottom spin simply would not act.

If you hit a double with side, you can control the angle. The effect seem to indicate that side is transferred to the object ball making it bounce off the cushion with a significantly different angle, don't you think?

The transfer of side takes place very briefly, and it is hard to see because the object ball will not keep spinning afterward in most cases.

[DandyA]

Actually Steve Davis did say something else later.

yep, can't remember where but I've seen Steve say in later years that he believes some transfer of side is possible using more modern balls - although I don't know whether he was referring to crystallite or phenolic ...

Where do you think the rotational energy goes if they do not get transmitted upon impact to the object ball? Does it all get lost in friction, sound, and so forth upon impact?

doesn't most of the rotational energy (ie side) stay on the cue-ball? for instance, if you apply side to the cue-ball, hit the object ball and then the cue-ball hits the cushion, you can clearly the cue-ball still has lots of side on it ... surely conservation of angular momentum applies every much as conservation of linear momentum, so if the cue-ball still has significant side after impact with the onject ball, it follows that not much (if any) could have transferred to the onject ball ...

I've seen some 9-ball vids showing signigicant trasnfer of side (Dr Dave?) but I don't really know 9-ball that well - I guess they use a different type of ball - and although I haven't seen it, it should also be possible to show the side has *transferred* - ie the cue-ball has lost the a significant amount of the side it had on it ...

[poolqjunkie]

yep, can't remember where but I've seen Steve say in later years that he believes some transfer of side is possible using more modern balls - although I don't know whether he was referring to crystallite or phenolic ...



doesn't most of the rotational energy (ie side) stay on the cue-ball? for instance, if you apply side to the cue-ball, hit the object ball and then the cue-ball hits the cushion, you can clearly the cue-ball still has lots of side on it ... surely conservation of angular momentum applies every much as conservation of linear momentum, so if the cue-ball still has significant side after impact with the onject ball, it follows that not much (if any) could have transferred to the onject ball ...

I've seen some 9-ball vids showing signigicant trasnfer of side (Dr Dave?) but I don't really know 9-ball that well - I guess they use a different type of ball - and although I haven't seen it, it should also be possible to show the side has *transferred* - ie the cue-ball has lost the a significant amount of the side it had on it ...

Yes, the conservation of angular and linear momentum holds, taking into account energy lost due to friction, sound and so forth.
But as you agree that linear momentum is transferred, should angular momentum have as well?
Have you watched this interesting video?
http://www.youtube.com/watch?v=ql-vXWEA_TU

[davipp]

Walter Lindrum believed side could be transmitted & demonstrated by placing the red near the left top pocket & playing an in-off using left hand side which made the red come off the cushion at a wide angle, playing from the exact same spot, he used right hand side which made the red come off at a narrower angle. He left it up to the scientist to prove him right or wrong. Whether this is throwing the ball or tranmitting side to cause the different line of travel is still baffling us after all these years.
I must watch some slow mo on this

[lkomarci]

Actually Steve Davis did say something else later.

Where do you think the rotational energy goes if they do not get transmitted upon impact to the object ball? Does it all get lost in friction, sound, and so forth upon impact?

If not, then they must have gone somewhere. So, where does it go?

When you hit a ball with spin to the cushion, the cushion absorbs a lot of the rotational energy as it is more elastic then the ball, but still side energy is not totally lost. The rotational energy was partly transferred to the cushion causing the ball to go wider/narrower. The result is quite significant. Why do you think this transfer of rotational energy will not happen when a ball hits another ball?

Even though the surfaces between two balls seem quite smooth but there are friction acting upon impact. If there was no friction, how could you draw a ball back? When the two balls collide, the bottom spin simply would not act if the balls have no friction between them.

If you hit a double with side, you can control the angle. The effect seem to indicate that side is transferred to the object ball making it bounce off the cushion with a significantly different angle, don't you think?

The transfer of side takes place very briefly, and it is hard to see because the object ball will not keep spinning afterward in most cases.

First of all, the energy doesnt get lost, it simply cannot get lost it just goes from one form to another.

The kinetic energy is passed from the cue onto the cueball and onto the object ball. Now the cueball has a certain amount of kinetic energy, and part of the kinetic energy is this rotational energy. So, by hitting the side of the cueball, its gets angular velocity. But the question is how strong this rotational energy should be to have an influence on the object ball considering the smooth surface?

The thing about friction is not doubtful at all, and the reason why the ball is going backwards is because of the table cloth. When you play the screw shot, the cueball doesnt spin forwards, the ball spins around its axis backwards (rotational energy) so most of the rotation is maintained, but the ball slides on the cloth forwards because of the linear kinetic energy, so when it finally collides with the object ball, the forward momentum is lost, but the ball is still spinning backwards, so once it "grips" the cloth it starts to spin backwards. Some of the rotational energy does pass onto the object ball, but should that mean that the object ball should slow down or increase its velocity because of the backspin on the cueball? It doesn't now does it?

[DandyA]

Yes, the conservation of angular and linear momentum holds, taking into account energy lost due to friction, sound and so forth.
But as you agree that linear momentum is transferred, should angular momentum have as well?
Have you watched this interesting video?
http://www.youtube.com/watch?v=ql-vXWEA_TU

yep saw that vid a while back ... absolutely amazing I haven't watched it tonight but if you're suggesting it as an example of transferred side-spin, I wouldn't be so sure ... the object ball is too close to the cushion so spin-induced throw works just as well as an explanation, doesn't it?

by the way, I'm not saying you can't transfer side ... I'm just saying the amount transferred must be tiny and hence of no practical use with phenolic snooker balls (dunno about American 9-ball) ...

good discussion by the way and I'd love you to prove me wrong