Amazing BILLIARDS PHYSICS in Super Slow Motion

Dr. Dave,

I am certain most readers have heard the expression, “A picture is worth a thousand words.”

Well, the video you just shared with all of us has to be worth a few million then. When you see
in action what you have been reading about, studying or even doing, and the video is in high
speed and macro like and accompanied by astute commentary, it makes comprehension so
much more easy. No matter how hard one tries, the human eye has limitations that a camera
doesn’t. As always, you have provided more very helpful information gratis to the Forum members
and the at large pool playing community. Thanks for you inquisitiveness and excellent tutorials.

Matt B.

I'm glad you think it is worth so many words.

My pleasure. I really had fun creating this video. It has been a while since I had thought through the details of some of this stuff.
 
great video, its very focused on the table actions.

impressive imaging of pool actions

Thanks.

I will try to make a competing video focusing on the differences of a players physical measurements and how it changes their stance.

I look forward to seeing it. FYI, I have some good advice to help people find their personal ideal stance, regardless of their anatomy and limitations, here (see the last two videos):

stance advice resource page
 
The thermal video was incredible, not just on the burn spot but along the path as the ball continues to spin. What was the temperature scale of the image? What variable has the greatest impact on the magnitude of the burn: rotational acceleration, forward acceleration, downward force?

I love the infrared stuff too. The color temperature scales are shown in the video. For example, with the masse shot, the scale shown is 34.2-37 C, which corresponds to 93.6-98.6 F. But this isn't really useful (except visually) because the interesting hot spots are going off the scale. The cloth fibers on the surface get really hot (many hundreds of degrees F); although, you wouldn't be able to feel it, and it cools quickly.
 
Thank you, and you're welcome.



Every curved-ball path on a pool table (assuming the ball isn't hopping) is a parabola. The math and physics proof (one of my favorites) can be viewed here:

TP A.4 – Post-impact cue ball trajectory for any cut angle, speed, and spin

It's actually not that difficult to follow along and understand if you just read the text and skip the equations.

Enjoy! o_O
Yes, parabolic path is not new to me, but I liked the way you presented and explained it.
 
Thank you, and you're welcome.



Every curved-ball path on a pool table (assuming the ball isn't hopping) is a parabola. The math and physics proof (one of my favorites) can be viewed here:

TP A.4 – Post-impact cue ball trajectory for any cut angle, speed, and spin

It's actually not that difficult to follow along and understand if you just read the text and skip the equations.

Enjoy! o_O

Yes, parabolic path is not new to me, but I liked the way you presented and explained it.

Did you check out the math and physics?

There will be a quiz tomorrow. :geek:
 
Great video Dave. Really enjoy the thermal imaging...

If you get bored, I have one for you. How about an attempted jump shot with a LD shaft...?
 
Excellent that you have already done a similar comparison. However it was a demo / compare using the ultra slow mo that I was hoping for. A stroke angle known to have the LD shaft fail.

My contention is that its the flex of LD shafts that make them bad jumpers. The super slow mo jump performed in your latest video supports my thoughts, but having the comparison to a LD shaft would cement my beliefs.
 
Did you check out the math and physics?

There will be a quiz tomorrow. :geek:
I might have checked it at a different moment in life. I had a very high finish in the 1975 National Math Olympiad for high school students, so I can understand it, but my knowledge of physics is very elementary. This math geek will leave the physics to the Dr Dave's of the world.

Funny you mentioned that it's your favorite proof. Made me think of something a top math professor once told me. According to him, ask a person what's their favorite theorem or proof, and if they reply without having to think about it, they are a math geek. Only the true math geeks, he suggested, even have a favorite proof or theorem. FYI, my favorite is Euclid's proof that the set of prime numbers is infinite.

Looks like I'm gonna flunk the quiz tomorrow, LOL.
 
Excellent that you have already done a similar comparison. However it was a demo / compare using the ultra slow mo that I was hoping for. A stroke angle known to have the LD shaft fail.

My contention is that its the flex of LD shafts that make them bad jumpers. The super slow mo jump performed in your latest video supports my thoughts, but having the comparison to a LD shaft would cement my beliefs.

Agreed. It would be nice to see LD-shaft jumps in super-super-slow motion to see when (angle, tip position, etc.) and why they result in poor jumps. I agree with you that the shaft-end flex is probably an important factor. The CB must be getting partially trapped by the tip on rebound. A stiffer and lighter cue with a harder tip (especially phenolic) and more-efficient hit does a better job of allowing the CB to clear on the rebound ... like a jump cue.
 
I might have checked it at a different moment in life. I had a very high finish in the 1975 National Math Olympiad for high school students, so I can understand it, but my knowledge of physics is very elementary. This math geek will leave the physics to the Dr Dave's of the world.

Funny you mentioned that it's your favorite proof. Made me think of something a top math professor once told me. According to him, ask a person what's their favorite theorem or proof, and if they reply without having to think about it, they are a math geek. Only the true math geeks, he suggested, even have a favorite proof or theorem. FYI, my favorite is Euclid's proof that the set of prime numbers is infinite.

TP A.4 is my favorite pool proof because it involves lots of different math, geometry, vector, and physics techniques and principles with several interesting and intuitive results. My favorite non-pool proof has to be any of Einstein's work on the mass/energy, special relativity, and gravity. That was a truly unique and brilliant collection of discoveries and proofs.


Looks like I'm gonna flunk the quiz tomorrow, LOL.

Don't lose too much sleep tonight worrying about it. I probably won't give you a quiz after all. o_O
 
FYI, I just posted a new video that explores the amazing world of billiards physics in super slow motion. I pulled from many past and recent resources, both from my video collection and elsewhere. Check it out:


It includes narrated slomo clips in each of these categories (with YouTube timestamp links):
0:00 - Intro
0:19 - 1 - Backspin and Topspin
1:27 - 2 - Corner Pocket Rattle
2:07 - 3 - Curved CB Paths and Burn Marks
3:13 - 4 - Rail Cut Shot CB Control
4:33 - 5 - CB Deflection
5:32 - 6 - Tip Compression
5:50 - 7 - Cue Vibration
6:03 - 8 - Cushion Compression
6:59 - 9 - Jump Shots
8:52 - 10 - Break Shot Technique
9:28 - Wrap Up
9:42 ---- clip montage

As always, I look forward to your feedback, comments, questions, complaints, and requests.

Enjoy!

I honestly thought the word "Physics" in the video title might scare people off, but I am happy to report that this video received more views in its first 4 days than another other video I have posted since 2006!

I guess people like pool physics after all if it is presented with lots of visuals and simple explanations.

Thanks to everybody for watching and offering feedback,
Dave
 
If you don't think the super close jump was a foul, calculate the predicted parabola and landing point of the cue ball and then the actual point of landing.
 
If you don't think the super close jump was a foul, calculate the predicted parabola and landing point of the cue ball and then the actual point of landing.

Good eye! I agree that the highly-elevated jump at the 8:03 point appears to be a double hit foul. The CB does take a minor course correction in mid air due to secondary contact with the shaft. I think this happens with most highly-elevated jumps like this, but it would be tough to call without super-slow-motion relay (and even then, the call can be tough, as in this example).
 
based on the thermals, its more accurate to say pool heats up and cools down much faster

Actually, the infrared video clips show that the "hot spots" heat up really fast and take a while to cool down. Regardless, IR imaging of pool is really "cool." :geek:
 
Actually, the infrared video clips show that the "hot spots" heat up really fast and take a while to cool down. Regardless, IR imaging of pool is really "cool." :geek:
an amazing player played that shot for film perfectly.
It is inspiring in the sense I might try to a video with a similar vibe.
 
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