Calling All Pool Scientists

Well... for one thing, what you need for these experiments are engineers, not necessarily scientists. Bob Jewett (Electrical Engineer) and Jim Buss (Aerospace Engineer) certainly fit the bill. Both know pool (national champion and master cuemaker, respectively)

I guess I'm not sure what you're really saying. What's a pool scientist?

Mike Page is a Physical Chemistry professor, a pool/billiard instructor, a pool hall proprietor, and a damned good player.

Dave Alciatore is a Mechanical Engineering professor, and has shared more billiard science knowledge than anyone. I think Dave's body of work speaks for itself.

Ron Shepard is also Physical Chemistry professor, A-player, and was the first to give us a physics view of pool and squirt with APAPP (Amateur Physics for the Amateur PoolPlayer).

Freddie

Bob jewett is a national champion? In what?

Anyway, the point here is the science guys are essentially enthusiasts and hobbyists. Nobody is denying their contribution but let's not overlook that.
 
Here is another way of trying to explain what others have also said. You are calling something significant or insignificant solely based on the number or percentage change. Context is everything but generally the terms significant or insignificant are not measurements of the number change at all, but of how much impact or effect that change actually has, and it was certainly used in that same normal way in the quote that started this line of the discussion.

If you have two grains of rice for your dinner instead of one grain, I can assure you that even though it is a 100% increase it has no significance to how hungry you will feel or how much nutrition it provided compared to what you need. It is insignificant. Even if your dinner was 10 grains of rice, an astronomical 1000% increase, it is still insignificant. Significance isn't how much a number moved, but how much it mattered.

Per your example, if I had 0 pieces of rice instead of 1, that wouldn't change how hungry I felt either.

Ipso facto, if the contact time is 0/1000 sec. there is no change in the effect of the cueball.

Maybe doubling the contact time doesn't affect things much. Maybe it is actually worse, maybe not. I am not convinced by anything I've yet read.
 
Maybe doubling the contact time doesn't affect things much. Maybe it is actually worse, maybe not. I am not convinced by anything I've yet read.

I'm wasn't arguing whether or not that change in contact time made any significant difference (although I have very serious doubts that it does for the record). What I was arguing was that your contention that if some measurement doubles, that it necessarily means that it has a great impact on something. It doesn't, but I think you already know that. :thumbup:
 
I'm wasn't arguing whether or not that change in contact time made any significant difference (although I have very serious doubts that it does for the record). What I was arguing was that your contention that if some measurement doubles, that it necessarily means that it has a great impact on something. It doesn't, but I think you already know that. :thumbup:

Okay, we are basically on the same page.

I don't know if the contact time matters, I haven't seen enough evidence to say. I had a problem with Mr. Lee saying it was insignificant without citing source material.

I never meant to insinuate that I believed that doubling the contact time made a huge difference. I intended to say that I have no idea whether it does or not.

Have fun!
 
I'd argue that it is more correct to use the term 'theory' in this case, but when not talking to those well versed in science, it is more effective to use the term 'fact'.

Semantics.
Dave knows better than you or SilverCue (or me) the difference between fact and theory.

There are lots of known facts about pool, and pretty much all of them are on Dave's website. Theories would be the explanations that link them and make them knowledge - some (but not a lot) of those are still in question.

pj
chgo
 
It isn't a negligible amount. EVERYTHING that the cueball does is caused by the contact time of the tip on the cueball. If you double the time, it stands to reason that different things will happen.

Let's look at it this way: The earth is about 4.5 billion years old. You might live to 80 or so. 80/4500000000 is insignificant, but if I offered a way for you to live to 160, you'd think it was pretty significant.

But the Earth wouldn't.


Per your example, if I had 0 pieces of rice instead of 1, that wouldn't change how hungry I felt either.

Ipso facto, if the contact time is 0/1000 sec. there is no change in the effect of the cueball.

Except in this circumstance you've eliminated contact. There is no contact time and that IS significant.
 
I'm not a pool scientist, but I did stay at a Holiday Inn Express last night, and I know that when you double an insignificant amount it becomes twice as insignificant.

For God's sake man ... everybody know that. :scratchhead::shrug:
 
But the Earth wouldn't.




Except in this circumstance you've eliminated contact. There is no contact time and that IS significant.

No, the earth wouldn't know the difference which is my point exactly. The age of the earth has no bearing on whether his extra 80 years are significant to him.

This all started because Mr. Lee called the contact time insignificant. It isn't insignificant because that is all there is in regards to contact time. Perhaps doubling the contact time (which is a significant amount...based on contact time) will have insignificant effects on the outcome, but doubling the contact time is still a significant increase.

I don't get how people will argue this kind of stuff on a different frame of reference.
 
I'm not a pool scientist, but I did stay at a Holiday Inn Express last night, and I know that when you double an insignificant amount it becomes twice as insignificant.

For God's sake man ... everybody know that. :scratchhead::shrug:

I think there is a double negative in there somewhere...
 
Perhaps doubling the contact time (which is a significant amount...based on contact time) will have insignificant effects on the outcome, but doubling the contact time is still a significant increase.
Significant isn't about quantity - it's about importance. If it doesn't change the outcome, it's not important (not significant) in pool.

pj
chgo
 
Significant isn't about quantity - it's about importance. If it doesn't change the outcome, it's not important (not significant) in pool.

pj
chgo

Yeah, yeah, yeah. I already explained that I am not convinced that it doesn't change the outcome. I respect many of the people who have done some work on this, but I remain unconvinced until I review it more.

So I am taking the stance that it might be significant.

I've explained this. In this thread. You do this often. You choose one stupid thing that you can argue to make yourself feel good and try to debase people who admit they are simply unconvinced.

Just like the theory thing. Scientific language has defined the scientific use of the term 'theory' and I believe that the person you jumped on used it correctly. Nothing against Dr. Dave, he has done amazing work. The fact is, tho, that all of that work is based off of scientific laws and theories and all of it is therefore theory.


Edit to add: This is why I have a very hard time taking you seriously. Scientists call things theories for a reason. There are theories that have stood every test, yet they are still called theories because scientists by nature and training keep their minds open to new possibilities. Your mind is like a bear trap, you can never open it to any other ideas.
 
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No, the earth wouldn't know the difference which is my point exactly. The age of the earth has no bearing on whether his extra 80 years are significant to him.

This all started because Mr. Lee called the contact time insignificant. It isn't insignificant because that is all there is in regards to contact time. Perhaps doubling the contact time (which is a significant amount...based on contact time) will have insignificant effects on the outcome, but doubling the contact time is still a significant increase.

I don't get how people will argue this kind of stuff on a different frame of reference.

Contact time is not all there is during contact time. As the time is increased, the force is decreased. It pretty much evens itself out.

Try looking at it like punching someone with and without boxing gloves on. (padded gloves same size as the hand) Which one will stay in contact longer, and which one will provide the most force?

All you have is speed of stroke, angle of cue at contact, and location on cb of contact. If the last two stay the same, all you have left is speed. Some of the speed is lost compressing the tip. That is made up by longer contact time. But, longer contact time in itself adds nothing of consequence because you can't just add time without decreasing speed or force.

If one could add contact time by itself, there would be a difference. As is seen with spinning a basketball on your finger. But, with a cue and a cb, that can't be done. Some think it can be done with swiping, but fail to understand the tip is still on the cb for the same amount of time. It doesn't increase time on the cb like they think it does because the mass of the cue and tip and the cb doesn't change.
 
Contact time is not all there is during contact time. As the time is increased, the force is decreased. It pretty much evens itself out.

Try looking at it like punching someone with and without boxing gloves on. (padded gloves same size as the hand) Which one will stay in contact longer, and which one will provide the most force?

All you have is speed of stroke, angle of cue at contact, and location on cb of contact. If the last two stay the same, all you have left is speed. Some of the speed is lost compressing the tip. That is made up by longer contact time. But, longer contact time in itself adds nothing of consequence because you can't just add time without decreasing speed or force.

If one could add contact time by itself, there would be a difference. As is seen with spinning a basketball on your finger. But, with a cue and a cb, that can't be done. Some think it can be done with swiping, but fail to understand the tip is still on the cb for the same amount of time. It doesn't increase time on the cb like they think it does because the mass of the cue and tip and the cb doesn't change.

I agree with much of your posts...but...

...as contact time increases, there are certainly more variables and it is very apt that you cite the force as being different. Most of the calculations I am familiar with being used to describe this use elastic collision equations. As the contact time becomes longer because of the energy lost in the compression of the tip, these equations become less accurate.
 
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My understating of impulse, which I believe this discussion falls under, is only so-so.

From a purely observational standpoint, however, I have done experiments comparing sticks with phenolic tips, and sticks with regular tips. They all made the CB do the same thing, when:
1) the contact mark from the chalk was held to the same spot on the CB
2) the stroke speed was adjusted to make the CB go the same distance
3) the stick sideways angle (but not contact point) was adjusted depending on the cue's squirt characteristics.

Patrick and others here have done these same experiments. (I got the test from Patrick). Its easy to see that the tip hardness has no measurable affect on the CB path, as long as it does not miscue.

Try for yourself:)
 
Cor! All that from asking what he is a champion in? Every day's an education...

I could be off on the year, but if memory serves it was the 1975 ACUII National Straight Pool Championships. Puts him on a short list that includes Nick Varner, David Uwate (from the forum), Dan Louie etc.
 
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