Pool Table Physics with Dr. Dave Alciatore

What was Coriolis, of the Coriolis Effect, doing at the pool table? On this episode, Neil deGrasse Tyson and co-hosts Gary O’Reilly and Chuck Nice explore the science behind billiards and pool trick shots with billiard physicist Dr. Dave Alciatore.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:01Neil deGrasse Tyson?

  Welcome to StarTalk. Your place in the universe where science and pop culture collide. StarTalk begins right now. This is StarTalk Sports Edition. And you knew we had to get here eventually. On this episode, we're doing the physics of billiards. Yeah, I said it, billiards. The pool, I guess, is also a pool, is that right?

• 0:30Chuck Nice?

  That's right.

• 0:31Neil deGrasse Tyson?

  Yeah, yeah, yeah, the physics of that. And you know there's physics going on, on that pool table. And so we are long overdue for handling this. And I got with me my trustee co-host Chuck Nice.

• 0:42Chuck Nice?

  Hey, that's right. And one of my favorite subjects, pool. I just, I could have bought another house with all the money I've lost at a pool.

• 0:50Neil deGrasse Tyson?

  Okay, thank you. It comes out for the first time on StarTalk.

• 0:57Chuck Nice?

  There you go, there you go.

• 0:58Neil deGrasse Tyson?

  Chuck's debts in life. And of course Gary O'Reilly, Gary, former soccer pro.

• 1:03Gary O'Reilly?

  Yes, I know.

• 1:04Neil deGrasse Tyson?

  Over in the UK. Oh, yeah. And Gary, I'm always impressed just with your genuine interest in all things that are not soccer.

• 1:12Gary O'Reilly?

  Yes.

• 1:13Neil deGrasse Tyson?

  So I'm delighted we have you as my co-host here. So we got this in three segments. One, we're going to talk about, we titled Coriolis Impact. Coriolis, ooh. There's more about Coriolis coming up. And then we're going to talk about trick shots, how could you not? Okay? And another one about the angles. It's all about the angles on the billiard table.

• 1:34Chuck Nice?

  The only time geometry is super cool.

• 1:36Neil deGrasse Tyson?

  Yeah, so when you're in school and you say, I never have to know this again. Yes, you will, if you want to become a pool shark.

• 1:42Chuck Nice?

  That's right.

• 1:43Gary O'Reilly?

  There you go.

• 1:44Chuck Nice?

  There you go.

• 1:46Neil deGrasse Tyson?

  That's how that works. So before we introduce our pool expert, Gary, give me some background on this sport and this activity.

• 1:55Gary O'Reilly?

  Okay, let's do a brief history, and I really mean brief. So back in the 1400s, the British and the French.

• 2:01Neil deGrasse Tyson?

  Damn, okay.

• 2:02Gary O'Reilly?

  And I'm not talking 2 o'clock in the afternoon, right?

• 2:07Chuck Nice?

  It's like, hey Chuck, can you give us your bio? I was born the son of a share, crapper.

• 2:14Chuck Nice?

  The son of a son of a shit cramp.

• 2:17Neil deGrasse Tyson?

  I thought all of billiards began with the movie The Color of Money.

• 2:20Chuck Nice?

  Yeah.

• 2:21Gary O'Reilly?

  All right, so.

• 2:22Neil deGrasse Tyson?

  Or Minnesota Facts, okay.

• 2:24Gary O'Reilly?

  So here we go.

• 2:24Neil deGrasse Tyson?

  Okay, so go on.

• 2:25Gary O'Reilly?

  We way back. So it starts with the British and the French aristocrats who in the 1400s took lawn croquet indoors because during the winter months it was too cold and too wet. However, the color of the top is green to match the grass that was croquet was played on.

• 2:45Neil deGrasse Tyson?

  Whoa.

• 2:46Gary O'Reilly?

  Right now, the term pool is for pocket billiards that came from America. Where tables were introduced into horse track betting rooms, the betting there was often done in betting pools. So in the mid to late 1800s to provide them with something to do between races. Now here we go. Fun fact, now we're in the 1800s.

• 3:06Neil deGrasse Tyson?

  Wait, wait, because betting on races is not enough ways to lose your money. You gotta add some between the races.

• 3:11Gary O'Reilly?

  Yeah.

• 3:11Neil deGrasse Tyson?

  Okay, that's crazy. Okay, go on.

• 3:13Gary O'Reilly?

  So now we're in the 1800s, 1835 to be specific. Coriolis wrote a book on the physics of pool, which.

• 3:24Neil deGrasse Tyson?

  I know Coriolis.

• 3:25Gary O'Reilly?

  I know you do.

• 3:26Neil deGrasse Tyson?

  Coriolis. Me and Coriolis go way back. Don't, don't, don't, don't you badmouth this man.

• 3:31Chuck Nice?

  I think he's got an effect that you like.

• 3:34Gary O'Reilly?

  Yeah.

• 3:36Neil deGrasse Tyson?

  Let me see, it's called the Coriolis Effect.

• 3:38Chuck Nice?

  Wow, look at that.

• 3:38Gary O'Reilly?

  There you go.

• 3:40Neil deGrasse Tyson?

  More on that, more on that, but go on, okay.

• 3:42Gary O'Reilly?

  The book was published in French, but it wasn't translated into English until 2005.

• 3:51Chuck Nice?

  Wow.

• 3:51Gary O'Reilly?

  There's your fun fact. So we are now looking at one of the classic physicists, mathematicians with an avid interest, such an interest in the sport of billiards and pool, that he went away and wrote a book. Amazing.

• 4:08Neil deGrasse Tyson?

  Okay, so that kind of gives it a little more respect than how it, what it occasionally gets today. When we think of pool halls, we think of shady characters. You know, and of smoke in the air and somebody about to lose their money, somebody about to get beat up in the back alley. And, and it hides, cloaks the fact that to be good at this sport, you gotta know some science, you gotta know some physics. And maybe even a little bit of engineering, and since none of the three of us have this expertise, we combed the landscape and we found the spirit of Minnesota Fast.

• 4:48Chuck Nice?

  We found Minnesota Slim. Yeah.

• 4:52Neil deGrasse Tyson?

  We found Dr. David Alciatore. So you're retired professor emeritus?

• 4:59Speaker 03

  Yes, recently.

• 5:00Neil deGrasse Tyson?

  Recently, yeah, because you don't look old enough to be like emeritus. At Colorado State University, you got your PhD in mechanical engineering at UT Austin. And, okay, here it comes, ready? Dean and co-founder of, are you seated? Billiards University.

• 5:21Chuck Nice?

  Wow, okay. I'm gonna tell you something right now, Dave. It sounds a little like Trump University to me.

• 5:31Neil deGrasse Tyson?

  I'm just saying. No, no, he didn't mean nothing wrong by it, he's just saying.

• 5:36Speaker 03

  We have a line of fine steaks we offer as well.

• 5:42Neil deGrasse Tyson?

  What happened when you were a kid and you said, "Mama, Daddy, I'm gonna start at Billiards University"? I don't know how that would have played out back, back then, but we'll get into that in a minute. So you've got books on, on topics as varied as mechanotronics, I love that.

• 5:56Speaker 03

  Mechatronics, Neil, Mechatronics. Get with the program, man, get with the program.

• 6:00Neil deGrasse Tyson?

  Excuse me, Mechatronics, what's that about? That sounds like robots that'll take over the world.

• 6:04Speaker 03

  It's a, a more traditional name is electromechanical systems, which is basically a, you know, a merge, a merge of mechanical and electrical engineering with some, with some computer science thrown in. Right on.

• 6:15Neil deGrasse Tyson?

  Okay, and another book, How to Aim Pool Shots. I love that. And you got your own YouTube channel and Facebook page dedicated to pool and billiards. This is wonderful to have you on the show.

• 6:26Speaker 03

  I'm happy to be here. Thanks, Neil.

• 6:28Neil deGrasse Tyson?

  Broadening our sense and understanding of all the cool sports that engage people. So, we have like a million questions for you. So, any of us who've heard of Coriolis before, whether or not we knew it was an actual person, heard of the Coriolis force, tell me, what, tell me about Coriolis and billiards.

• 6:48Speaker 03

  Yeah, so Coriolis, you know, he wrote this brilliant book in 1835. I didn't see it until 2005, when the English version came out. And that was a year after I wrote my book. And I had done a ton of work, and when I saw Coriolis's volume of excellent work, I was just crushed. And my heart stopped.

• 7:05Neil deGrasse Tyson?

  Oh, you mean, he scooped you?

• 7:07Speaker 03

  Yeah, yeah, by a couple hundred years.

• 7:09Chuck Nice?

  Wow. Now, wait, did you reach the same conclusions, though, without knowing his work?

• 7:15Speaker 03

  Well, other people, you know, I'm not the only one that's done billiard physics. Other people have done stuff, and many people have come close to duplicating much of Coriolis's work.

• 7:23Neil deGrasse Tyson?

  Before we, we take a break, because I want to get to what you described. Could you let me know if, in this first book that you wrote, Mecatronics, could you devise a mechanical system that could play a perfect billiard game without anyone's intervention?

• 7:41Speaker 03

  Uh, that's the-

• 7:42Neil deGrasse Tyson?

  In the same way we can make machines that solve Rubik's cubes and machines that drive cars, can you do one where it's going to sink the ball every single time?

• 7:49Speaker 03

  Uh, yes, people have done this. Now, it's not, they're not good enough yet. They're not, they're not, they're far from a good player. But there are many robots that have been built that, that can, that can use vision systems, a camera, to see where the balls are, position itself, and-

• 8:03Neil deGrasse Tyson?

  It would know exactly where the ball is, right?

• 8:05Speaker 03

  Exactly, yeah.

• 8:05Neil deGrasse Tyson?

  High-res camera?

• 8:06Speaker 03

  Yes, exactly. So, they, they can see better than we can see. Uh, but they can't stroke as well as we can, and they can't plan as well as we do either. But you might think the planning piece, I think, can be there soon. But the work that's been done already in that regard, the planning is not quite there. The shot making is not quite there.

• 8:22Neil deGrasse Tyson?

  So just to be clear, when you say the planning, it means when I hit the ball, where the balls end up after my successful shot will matter for my next shot.

• 8:30Speaker 03

  Bingo.

• 8:30Chuck Nice?

  The leave.

• 8:31Neil deGrasse Tyson?

  The next shot.

• 8:31Chuck Nice?

  That's where the whole game is. The leave, man. It's all about positioning.

• 8:35Speaker 03

  Yep.

• 8:36Chuck Nice?

  You gotta play the position game.

• 8:37Speaker 03

  You got it, Chuck. You gotta make that shot, but you gotta make the cue ball go to a place where the next shot's gonna be easy.

• 8:42Chuck Nice?

  Right.

• 8:43Neil deGrasse Tyson?

  Chuck, why are you this fluent in this?

• 8:45Chuck Nice?

  Like I told you, man, could have bought a house with all the money I lost. It's a very expressive education. Very expressive education.

• 8:52Neil deGrasse Tyson?

  All right, when we come back, we gotta take a quick break, but when we come back, we will get into the details of the famous, or is it infamous, Coriolis shot on StarTalk Sports Edition.

• 9:15Neil deGrasse Tyson?

  We're back. StarTalk Sports Edition, all about billions, the physics of billions. Of course, that's how we roll on StarTalk.

• 9:23Chuck Nice?

  I see what you did there. That's how we roll.

• 9:26Neil deGrasse Tyson?

  Okay, all right. So we've got our guest, Dr. David Alciatore. Alciatore. Yeah, I want to pronounce it in its Italian way, and my tongue is not letting me. Alciatore. But so Dave, this is great that you've done that, you've devoted your career to this, even with active social media presence promoting it. So let me hand over to Gary and Chuck, because I know they've got a million questions for you.

• 9:58Gary O'Reilly?

  We have, Neil, because it's so interesting. The Coriolis sort of situation, particularly with parabolic cue ball paths. It sounds as if I should not understand it, but I think I do, but I need a really good explanation from Dr. Dave.

• 10:15Speaker 03

  Okay, here it comes. You ready?

• 10:16Chuck Nice?

  Yep. Let's do it.

• 10:19Speaker 03

  Okay, so Coriolis, you know, if you studied the motion of a ball, Neil will appreciate this, you have to look at translation, how the ball is moving in a straight line or a curved path, and you have to look at rotation, how the ball is spinning and how that's changing during the shot. All right, so Coriolis, he did all the math, and he had to write what are called differential equations to describe these two effects. He solved these equations, and he figured out that... The direction of friction, you know, when the ball is sliding and skidding across the cloth, there's friction that's trying to slow it down and change the spin. Well, he discovered that the direction of the friction during a shot does not change. It's the same magnitude and same direction during the entire shot, no matter how you hit it. If it's skidding and spinning, it's gonna follow, I mean, the friction is gonna have, gonna be in the same

• 11:03Speaker 03

  direction for the entire shot. Now, once he discovered that, uh, cause he was smarter than most of us are now, you know, he had, he was creative in how he solved equations and, and he, he realized at that point, if the friction is the same force and in the same direction the whole time, it's gonna be just like gravity. You like this, Neil, cause gravity is always straight down. And when you have projectiles, projectiles, the force is always in the same direction, the same, the same magnitude, and that's why projectile. Interesting analogy. Follow a parabolic path.

• 11:33Chuck Nice?

  Wow, so it's the horizontal version of how gravity works in our environment.

• 11:39Speaker 03

  Very good.

• 11:39Chuck Nice?

  Or, or here on earth.

• 11:40Speaker 03

  I like it, I like it.

• 11:42Chuck Nice?

  Yeah, that's really cool, man.

• 11:44Speaker 03

  So there are certain shots where this applies, you know, anytime you, you hit the cue ball with top spin or bottom spin by aiming high or low on the ball. After it hits the object ball, the ball you're hitting, the cue ball starts sliding and then that spin takes over, it peels out and makes it curve. Well, that's an example of that, that curved shape is a parabola.

• 12:02Chuck Nice?

  Right.

• 12:03Speaker 03

  That's one place. Another type of shot where, where the coriolis aiming system applies. All right, so a masse shot, you know, a lot of, a lot of terms in, in pool came from the French because as, as Gary pointed out earlier, you know, pool started with the aristocrats, crats in France and, and England. So a masse shot is a French term, uh, where you actually strike down on the ball from above. Maybe you've seen some, some trick shot artists do this. Yes, yes. Strike down the ball off center and, you know, to one side and down into the table. It gives the cue ball a lot of spin, it gives it side spin and it gives it, it gives it what's called a barrel roll or kind of a, you know, like a, you can imagine a kayak kind of turning or, or spaceship spinning, a satellite spinning, it gives it that kind of. While it's going forward.

• 12:46Speaker 03

  While it's going forward, corkscrew, corkscrew spins, another name for it. So when you hit a masse shot, it also follows a parabolic path. So anytime the cue ball is not going straight, or any ball is not going straight, it's always following a parabolic path. That's one thing Coriolis proved. Okay, what's to do with the jump shot?

• 13:04Neil deGrasse Tyson?

  Wait, so Chuck is taking very careful notes.

• 13:07Chuck Nice?

  I know, I already knew that.

• 13:08Neil deGrasse Tyson?

  Win back that money. No, he has to win back some of that money.

• 13:11Chuck Nice?

  I wish I could, you know what I mean? By the way, the, what is it, amasse shot?

• 13:18Speaker 03

  Masse.

• 13:18Chuck Nice?

  Amasse. So I'mma call it the amasse shot. And that's when somebody does it and they say, "I'mma say you owe me some money." "I'mma say you owe me another $50." And by the way, that shot, in a trick shot, is where you see guys, there normally, there's an opponent's ball between your ball and the target ball. Between the cue ball and the target ball. And so what you want to do is go around their ball. And that's what that shot does. It allows you to literally go around the opponent's ball.

• 13:56Neil deGrasse Tyson?

  Okay Chuck, that's why we have Dave on the show.

• 13:59Chuck Nice?

  Oh, I'm sorry. Okay. By the way, Dave, tell us about that shot. Describe that shot for us.

• 14:07Speaker 03

  Well, that's when you want to bend the ball around another ball.

• 14:11Gary O'Reilly?

  All right, so now we know where we are, literally, on the table. If that shot, that masse shot, is blocked because of the cushions, I have to go airborne. Now, how on earth am I getting a stationary ball airborne by hitting down on it?

• 14:27Speaker 03

  All right, I'll talk about this, but we've got to go back to Coriolis.

• 14:30Gary O'Reilly?

  Okay, sure. It's not as if I can bounce it.

• 14:33Speaker 03

  Yes, yes, so that's called a jump shot. And I mean, some novice beginner players have probably executed jump shots before, but they haven't been the legal type. The illegal type is where you hit under the ball too low and it scoops up in the air. It's called a scoop shot. But that is not legal. Alright, for several reasons. One, it can damage the cloth. It's actually too easy to do it. It's very easy to do it if you try. So at some point, they wrote rules to prevent that kind of shot, but still allow a jump shot, but now you have to hit down on the ball. And that causes the cue ball to actually compress the cloth and bounce off the slate. You know, the bed of a pool table is made out of slate, geological slate. And slate's one of those materials of nature that engineers have not been able to beat.

• 15:17Speaker 03

  There's several materials like that in pool. We should talk about that, too. Like tips are still better.

• 15:21Neil deGrasse Tyson?

  So finish Coriolis.

• 15:23Speaker 03

  Alright, so that's one thing Coriolis discovered, that all paths on the table are parabolic, just like the shape of a reflector in a headlight. Alright, so let's get back to the second discovery that Coriolis found that I was just blown away by. And that's this Coriolis aiming system. Alright, I call it the bar system first. Let me tell you why. So imagine a ball. You're hitting a masse shot. So you're hitting down on the ball. So you're aiming at a point on the ball. That's the B, bar method. If you project your cue, the direction the cue is pointing onto the table, it's aiming at a point on the cloth. Alright, that's A, BA. Alright, now you have to, so that's one line. We have a line that's through the cue, hitting the ball, and aiming at a point on the cloth.

• 16:06Speaker 03

  Well, Coriolis, when he solved all the equations for these masse shots, I don't know how he did it, but he found a way to simplify the math at the end with some crazy geometry. And he found out that a straight line describes the final answer, even though the equations do not look like a straight line. Alright, now the straight line he found is from the resting point. If you imagine the resting point of the ball, that's the third point, R. So we have bar, ball point, aim point, resting point. Alright, so Coriolis found where the cue is pointing at the cloth. If you draw a line from the resting point of the ball to this aiming point on the cloth, imagine that line. That line shows you the angle, the final angle that the cue ball will head after it's done curving.

• 16:49Neil deGrasse Tyson?

  Right. Whoa.

• 16:50Speaker 03

  So I call this the Coriolis aiming system. Because if you want to aim a masse shot, you know, most people aim them by feel. But when I aim them, I actually look at the final line I want. I kind of project that line back to the cue ball with my cue stick. I add a little because it's not perfect. There's some imperfections on a pool table. I'd shift the line a little bit. And now I know where to aim my tip at the cloth, through the ball. And I can make that ball curve and follow that final path. Wow. This is the Coriolis aiming system.

• 17:18Chuck Nice?

  Wow, where was this book when I was losing all this money?

• 17:23Gary O'Reilly?

  So, so Dave, we've got terms like English, squirt, throw, and one I could probably understand, swerve. Um, what do they mean? What's it every, I mean, because English to me doesn't make sense, but it's very popular here in the US.

• 17:40Speaker 03

  Aren't you British? Aren't you British, Gary? Shouldn't you know what English is?

• 17:43Gary O'Reilly?

  Yeah, but not, not, not in the terms of billiards or pool. There's no such term in the UK.

• 17:48Chuck Nice?

  Well, Gary, in, in billiards, English is where you address the ball and you go, "I say, old man."

• 17:55Neil deGrasse Tyson?

  I say.

• 17:56Speaker 03

  Actually, yeah, actually, it is related. It is related to where, how you address the ball. Because where you address the ball with the tip.

• 18:02Gary O'Reilly?

  That's right. Chuck, normally what, Chuck, normally what happens is you have one's butler address the ball on your behalf.

• 18:09Neil deGrasse Tyson?

  No, I get it.

• 18:12Gary O'Reilly?

  Sorry, Dave, you were telling us how it works.

• 18:14Speaker 03

  Can I, can I talk now?

• 18:15Chuck Nice?

  Yeah.

• 18:18Speaker 03

  Didn't you guys, aren't I supposed to be the guest?

• 18:21Neil deGrasse Tyson?

  Yeah, yeah, yeah, he's the guest.

• 18:22Speaker 03

  You guys like my Italian family. If you want to be heard, you gotta talk louder and louder and louder.

• 18:28Gary O'Reilly?

  You're getting with the program.

• 18:29Speaker 03

  All right, so when you hit the ball off center, you impart side spin, clockwise or counterclockwise spin. All right, now, in the early days.

• 18:36Neil deGrasse Tyson?

  Just to be clear, that's clockwise or counterclockwise, seen from above.

• 18:38Speaker 03

  Seen from above, yes. So when you hit the left side of the ball, you're imparting clockwise spin. Yeah, looking from above.

• 18:45Gary O'Reilly?

  Right.

• 18:46Speaker 03

  So, you know, in the early days, Gary mentioned that pool originated from the aristocrats, that, you know, because the weather was so bad in England, they had to put, bring croquet inside. They put it on a table. The balls kept rolling off, so they put these rails on the table. Uh, now, when the balls got close to the rails, you know, the croquet mallet, if you can, it's like a hammer, right? Usually you hit it with the, with the hammer part, the mallet part. But when the balls were close to these rails they put on the tables, they had to turn it around and hit it with the end of the mallet. That's where the pool cue, that's where the pool cue came from. And for many hundreds of years, that pool cue was just a bare piece of wood, just like the end of a croquet mallet. All right, now, with a bare piece of wood, you cannot hit the ball off center very much. If you do, it slips right off.

• 19:28Gary O'Reilly?

  Right.

• 19:29Speaker 03

  All right, so in the early 1800s, around the same time of Coriolis. Some guy anecdotally decided, because their pull cue kinda cracked on the end, they anecdotally took a piece of leather from their shoe and kinda nailed it on to the end of the cue. I'm not sure how they nailed it, but they got a piece of leather on the end of their tip and allowed them to hit the ball off-center now. You know, it's anecdotal, but this is kinda true. You know, that's how the pull cue evolved. Somebody put a piece of leather on the end of the tip one day, and now they discovered they could hit the ball off-center and apply spin. Now, I'm answering Gary's question, where did the word "English" come from? Alright, because after these leather tips were kinda invented, around Coriolis's time, this English guy came to America and was giving these exhibitions.

• 20:13Speaker 03

  And he had this leather tip on there. Nobody in America had that yet. And this English guy was hitting all these wicked shots, like masse shots, and spinning the heck out of the ball, making the ball dance around the table. Well, the Americans hadn't seen that. They said, "Look at this English guy hitting these English shots." "English."

• 20:28Chuck Nice?

  No, "English."

• 20:29Neil deGrasse Tyson?

  Mmm, okay.

• 20:31Chuck Nice?

  And by the way, the "English" is so necessary when we talked earlier about where you leave the ball.

• 20:38Neil deGrasse Tyson?

  Right, after the shot.

• 20:40Chuck Nice?

  After the shot.

• 20:41Neil deGrasse Tyson?

  Now, something we have that's become almost... We've gotta take a quick break in a second, but something we have that's almost trope is the person who just sits there and puts the chalk on the tip of the... While they stare... They're not saying anything. They're just putting the chalk on. You know you're gonna get ass-whupping, right?

• 20:59Chuck Nice?

  That's right.

• 21:01Neil deGrasse Tyson?

  So, when did chalk come into this? I guess chalk and slate go together. As an educator, that's what's in the front of a classroom. Chalk and slate.

• 21:10Speaker 03

  Yes. Now, the chalk, it's not... The slate is geological slate, but the chalk is not geological chalk. It kinda looks and feels like it, but it's made differently.

• 21:20Neil deGrasse Tyson?

  It's made from tums they get from the...

• 21:24Speaker 03

  From the hearth burn you get by watching a guy chalk.

• 21:26Neil deGrasse Tyson?

  From the hearth burn.

• 21:27Chuck Nice?

  You can eat it while you're losing.

• 21:31Neil deGrasse Tyson?

  As you get the indigestion for losing.

• 21:33Chuck Nice?

  It's lose your oxygen while you're losing.

• 21:36Speaker 03

  Well, I mentioned the leather tip. We still use leather. You know, it's been 200 years. Engineers have not improved on leather. It's just really, it's really good stuff. Dead animal skin is the best thing to put on the end of a cue, pull cue.

• 21:47Neil deGrasse Tyson?

  So there's no vegetarian pool sharks. That's what that comes down to.

• 21:51Speaker 03

  I've had several people ask me if there's a vegan alternative and there are some, but it's not acceptable to a good.

• 21:56Chuck Nice?

  Yeah, there's a vegan alternative. It's called losing.

• 22:01Neil deGrasse Tyson?

  That is so blunt.

• 22:03Speaker 03

  The chalk is to give the tip more friction. The leather grabs fairly well, but when you add this chalk, which has a bunch of abrasive particles in it. So it's a chalk-like substance that's mixed in with some little abrasive particles. It's kind of like a fine sandpaper. But when you apply that.

• 22:18Neil deGrasse Tyson?

  Yeah, but is it a different? Wait, wait, wait. But don't gymnasts use chalk to reduce friction?

• 22:23Speaker 03

  That's different. That's just to absorb moisture like talc.

• 22:26Neil deGrasse Tyson?

  Oh, moisture from their, oh, from their palm of their hand.

• 22:29Speaker 03

  Bowlers use the rosin, they use a rosin bag, same thing to take moisture off the hands. Yes.

• 22:34Neil deGrasse Tyson?

  I got it. Got it. Okay. So let's take a quick break. When we come back, I want to hear a little bit more about trick shots and also some of the culture of what it is to be a billiards shark. StarTalk Sports Edition.

• 22:59Neil deGrasse Tyson?

  We're back. StarTalk Sports Edition, the physics of billiards. And we have one of the world's experts on who thinks about the physics of billiards. It's Dr. David Alciatore. Al, Al, Alciatore.

• 23:13Speaker 03

  Yes.

• 23:14Chuck Nice?

  Just call him Alciatore.

• 23:16Speaker 03

  Alciatore. You gotta use your hands.

• 23:19Neil deGrasse Tyson?

  I want to say it that way and I'm trying to, my body won't let.

• 23:23Speaker 03

  Dr. Dave, use your hands.

• 23:24Neil deGrasse Tyson?

  Just call him Dr. Dave. Dr. Dave. That's how what I'm gonna do. So Dr. Dave, we all love trick shots. Do they have any real role in competitive billiards?

• 23:36Speaker 03

  Yes, there are what are called artistic billiards competitions where the feature is trick shots.

• 23:41Neil deGrasse Tyson?

  Oh, okay. And so are they, I'm curious because in the All-Star break in basketball, they have the slam dunk competition. In the All-Star break in baseball, they have the home run derby. So these are the fun things that can show up in a regular game. Now they're all focused down into one slot, into one offering. So I guess what I'm asking is, are there occasions where a completely crazy trick shot would be necessary in competitive play?

• 24:12Speaker 03

  Yes. In fact, we talked about a masse shot where you try to curve around an obstacle. That is usual play.

• 24:18Neil deGrasse Tyson?

  And that counts as a trick shot?

• 24:20Speaker 03

  Yes. Now, in trick shots, they do very dramatic versions of that. But you know, in an actual game, if you have like, you seem to curve it a little bit, a few inches, you can do that pretty reliably.

• 24:30Neil deGrasse Tyson?

  And a lot of trick shots, they involve a pre-set up of what the balls look like on the table.

• 24:35Speaker 03

  Bingo.

• 24:36Neil deGrasse Tyson?

  Yeah. So that's makes it, is the art of the setup so that your ball can do what it needs to.

• 24:42Speaker 03

  And the other trick shot is the jump shot, you know, which we started talking about before, where we hit the ball at a downward angle, causing it to compress the cloth, bounce off this natural slate. And that's a legal jump shot. I didn't finish that thought earlier. It's a legal jump shot. You can make the cue ball bounce over, over an entire obstacle ball. And this is a very important weapon in modern pool.

• 25:01Neil deGrasse Tyson?

  So what are the balls made of to enable them to do this?

• 25:05Speaker 03

  They're made out of a phenolic resin. It's a thermoset material, it's called. But it's a phenolic. It's called a phenolic, it's a resin.

• 25:12Neil deGrasse Tyson?

  A phenolic resin?

• 25:13Gary O'Reilly?

  I know, but Dave, historically, weren't they made of ivory?

• 25:17Speaker 03

  Yes. And I have to collectively apologize for my entire sports history because we killed lots of elephants in the past.

• 25:25Neil deGrasse Tyson?

  Oh!

• 25:26Speaker 03

  And the real sad part of the story is that you only got about three balls out of one tusk.

• 25:33Neil deGrasse Tyson?

  Oh, no.

• 25:34Speaker 03

  So can you imagine how many elephants had to die to help this sport?

• 25:40Speaker 03

  Now, we talked about the slate and the leather tip that engineers haven't been able to improve upon nature's incredible evolutionary feats. But the ball, we did find a better alternative to ivory.

• 25:52Gary O'Reilly?

  What about the cue? I mean, are we stuck in historical tradition and it's wood only? Or have we made any advances there?

• 26:01Speaker 03

  Well, since the 1400s, it's been a wood cue, just like that original, a croquet mallet. And just in recent years, in the last 10, 10 or so years, has carbon fiber

• 26:12Neil deGrasse Tyson?

  Carbon fiber.

• 26:13Speaker 03

  Come out and it's, and you know, there's been other attempts in the past with fiberglass and aluminum, but they just did not, they did not sell, you know, nobody, nobody, and you couldn't play well with them. Carbon fiber is the first true revolution in pool equipment. Otherwise, nothing has changed, nothing has changed in hundreds of years.

• 26:28Neil deGrasse Tyson?

  Yeah, but wait, Dave, if you're trying to hit the ball, some of what matters is the momentum that the cue stick has that you're imparting on the ball. And if you go to carbon fiber, which is obviously lighter than wood, in order to get the same momentum, I have to push the stick harder into the ball. And maybe I don't want to do that. Maybe I just want a heavier, a heavier bat, as we'd say in baseball. So what is the carbon fiber doing for you?

• 26:54Speaker 03

  Well, the only thing that's made of carbon fiber is the shaft, the front, the front end of the cue.

• 26:58Neil deGrasse Tyson?

  Right.

• 26:59Speaker 03

  You know, most good cues are in two pieces, the shaft and the front piece.

• 27:02Neil deGrasse Tyson?

  Yeah, I see when they walk in, when a dude walks in the pool hall with a suitcase and, and opens a suitcase and, and attaches one piece to the other, that's when it's time to say, okay, you win.

• 27:15Neil deGrasse Tyson?

  These are people not using the, not using the company cue sticks on the thing, right? They got their own.

• 27:22Gary O'Reilly?

  From our conversation so far, as Chuck said it quite succinctly, it's all about the league. But how many shots ahead is a high-end pool billions player actually mentally calculating?

• 27:34Neil deGrasse Tyson?

  Oh, yes.

• 27:35Speaker 03

  That's a great question.

• 27:36Neil deGrasse Tyson?

  No, no, no, you should know, we gotta say that differently. How many are they capable of knowing, given the chaos and the randomness of what happens? Oh, man, this is great. Go ahead, Dave.

• 27:48Speaker 03

  Great question, great question. And by the way, Neil, a good player does not experience much, much, much chaos or random.

• 27:53Neil deGrasse Tyson?

  Oh, excuse me.

• 27:57Speaker 03

  The answer depends on the game, on the game you're playing partly. So I did want to mention, you know, eight ball is the most common game in America. Most people know what that is. You have to hit the solids or the stripes first, then pocket the eight.

• 28:07Chuck Nice?

  Nine ball is where the action is, baby.

• 28:09Neil deGrasse Tyson?

  Wait, wait, wait. It's the only game ever where the black thing is last rather than first off the table.

• 28:16Chuck Nice?

  Yeah, yeah, but the white ball still controls everything.

• 28:21Speaker 03

  Very racist game, very racist game.

• 28:24Neil deGrasse Tyson?

  Very, very, okay. Chuck, forgive me for forgetting that fundamental fact, okay?

• 28:28Speaker 03

  So the other game, nine ball, that's the game of choice in pro tournaments now. And it's also historically the gambling game. That's why Chuck knows it from his misspent youth.

• 28:36Neil deGrasse Tyson?

  Yeah. Uh huh, yeah, yeah.

• 28:38Gary O'Reilly?

  So the thing is, you've probably seen them, guys just turn up, grab a cue, and they intuitively know what they're doing. Kind of see it with some other athletes, but what are they calculating? You know, what sort of geometry are they able to see and feel just without having a scientific education?

• 28:59Speaker 03

  Well, you say it looks intuitive, but they are thinking about a lot. They just do it very quickly. And they're not thinking about, and even I don't think about physics and geometry when I'm at the table. Except in certain shots, I do have systems, geometric systems for aiming certain types of shots, like bank shots and kick shots where you're getting balls off rails. Then the geometry can help, but you still have to adjust for the real world physics on a pool table. You know, the pure geometry does not work by itself. But anyway, good players don't think about any of that. They just, they instinctively know how to aim, first of all. And, but when they're, when they're planning, they are doing a lot of planning. And they always think at least three balls ahead, especially in not in...

• 29:38Neil deGrasse Tyson?

  Three shots ahead, yeah, okay.

• 29:40Speaker 03

  Now, in a game like eight ball, you often have to think through everything if you're playing at a high level. You have to think about the whole game and work backwards from the eight ball. You got to first see where can the eight ball go? What should I choose solids or stripes? Well, if the stripes are blocking the eight ball, then you probably have to shoot stripes because otherwise eight ball can't go in anywhere. So you always think backwards and then you have to say, well, the eight ball is here. These other balls are in the way. Once I clear all my other balls, where do I have to get the cue ball to make that eight ball? So you gotta think about what is the key ball to help me get on the eight? That's the last ball you pocket, the last stripe or solid you pocket to get shape on the eight. That's the leave you talked about before Chuck, the shape.

• 30:17Chuck Nice?

  That's right. And sometimes, and sometimes what happens is you don't have a shot to move forward. So what you want to do then is play some defense to make sure that your leave puts your opponent at a disadvantage so that you're not leaving them with three shots that they could then go ahead and maybe go ahead and sink the eight ball on you.

• 30:39Neil deGrasse Tyson?

  Chuck, given your legendary billiard debt, why are we listening to any advice from you at all?

• 30:45Neil deGrasse Tyson?

  I just want to make it clear. I just want to be clear about this.

• 30:48Chuck Nice?

  Do what I do, not what I say. I mean, do what I say, not what I do. So let me ask you about, uh, because I-

• 30:54Neil deGrasse Tyson?

  We just have a couple more minutes Chuck, so let's hear it.

• 30:56Chuck Nice?

  It's not a trick shot, but multiple bank shots, which are, to me, one of the coolest things that you can see when you're playing pool. You know, a bank shot is a bank shot, but like when you have a ball hidden and you go two banks and then a third bank off the rail and just kiss it and knock the ball in, that kind of stuff is like, so when you're picking your spots, how do you maintain the site for all three spots? Because the first one-

• 31:26Neil deGrasse Tyson?

  And let me jump in here and say, I'm gonna jump in here and say, when you see the projected paths of hurricanes and the farther along the path of the hurricane, the wider is the uncertainty. You know that's going on on Dave's pool table. So let me ask you, Dave, how big does your uncertainty get? Even if you're highly talented at this, as it goes from one cushion to another cushion and that third cushion has got to have maximal uncertainty in where you expected it to go.

• 31:51Speaker 03

  Well, there's actually systems for aiming these types of shots. And what you're describing Chuck is called a kick shot. You know, when you hit an object ball, like a target ball, and you make it bounce off a rail, that's called a bank shot. But when you hit one or more rails first with the cue ball, that's called a kick shot. So there are several systems that are called diamond systems. You know why they're called diamond systems?

• 32:11Neil deGrasse Tyson?

  No.

• 32:12Speaker 03

  Cause there's diamonds on the table, on the rails.

• 32:14Chuck Nice?

  Yeah.

• 32:14Speaker 03

  And that answers your question.

• 32:16Neil deGrasse Tyson?

  Oh, okay. They're at the between points of the pockets.

• 32:20Speaker 03

  Yeah, between.

• 32:20Neil deGrasse Tyson?

  Is that what they're there for? I always wondered.

• 32:23Speaker 03

  That's what they're there for, to help, to help aim certain types of shots. And that's how, that's what you focus on. You focus that where you're shooting relative to the, relative to the diamonds on the first rail. Okay? Now, these diamond systems, they were developed many years ago, hundreds of years ago. And, you know, when we had this other game called billiards, we talked about, you know, pool is pocket billiards. Our tables have pockets in them. But the original billiards was, had no pockets. Uh, in fact, I don't know if you know the, the music, the musical, The Music Man? You know that?

• 32:50Neil deGrasse Tyson?

  Yeah.

• 32:51Chuck Nice?

  Yeah, right here in River City.

• 32:52Speaker 03

  You got it, right? We got trouble. We got trouble. You know what?

• 32:55Chuck Nice?

  And that starts with T and that rhymes with P. And that stands for pool.

• 32:59Speaker 03

  That stands for pool. The whole theme, the whole theme of that musical was that, uh...

• 33:04Neil deGrasse Tyson?

  Chuck, very good.

• 33:05Speaker 03

  Good job, Chuck. I'm impressed. I'm impressed.

• 33:07Neil deGrasse Tyson?

  Yeah.

• 33:07Speaker 03

  So the whole theme of that musical was that, uh, this billiard parlor, which was a very gentlemanly game, because it was, there were only, there were only three balls on the table, no pockets. The goal is to hit the first ball. And before you hit, and you had to hit the first ball into the second ball. You're, you're hitting a cue ball, and there's two other balls. So you hit the cue ball into the first ball. Before the cue ball hits the second ball, you have to contact at least three rails. That's the whole, that's the game. That's billiards. That's billiards.

• 33:35Neil deGrasse Tyson?

  So those folks know the geometry real well.

• 33:37Speaker 03

  Yes, and they came up with these systems to aim those types of shots. Now, the theme of this musical was that the billiard parlor in town was about to install an American pool table. And, and that was gonna corrupt the use of the town. So they, they needed something to, they needed something wholesome. They needed something wholesome to, to replace that, that corruption. And it was a marching band and this traveling...

• 33:55Neil deGrasse Tyson?

  They needed 76 trombones.

• 33:57Speaker 03

  Yes, exactly.

• 33:59Speaker 03

  Anyway, I got, what were, what were we talking about? I forget.

• 34:01Neil deGrasse Tyson?

  I, I don't know.

• 34:04Speaker 03

  I was talking about the diamond system. The diamond systems for aiming kick shots.

• 34:07Chuck Nice?

  Yeah.

• 34:07Neil deGrasse Tyson?

  Wait, so wait, so wait. So it mean, it tells me then that diamonds are a start. In some version of a pool table, you could completely calibrate all sides of the table, down to a millimeter.

• 34:19Speaker 03

  Yes.

• 34:19Neil deGrasse Tyson?

  Why not?

• 34:20Speaker 03

  Yes.

• 34:22Neil deGrasse Tyson?

  You could?

• 34:22Speaker 03

  Yes.

• 34:24Neil deGrasse Tyson?

  I don't need just one thing that divides it in two. Give me something that divides it into a thousand parts.

• 34:28Speaker 03

  I see what you're saying, yeah.

• 34:29Neil deGrasse Tyson?

  That would up, that would up my game, the precision of my game. And if you're teaching kids math and they say, in, in middle school, say, "I'll never need to know that for the rest of my life," I say, "Yes, you will." Okay, if you don't want to end up like Chuck, losing all your money. The customary tale of Chuck Knight.

• 34:46Speaker 03

  Well, we only have, you know, we have, we have eight diamonds on, on the length of the pool table and there's four on the, on the side. But pool players, we, we, we can, we can specify numbers in between those diamonds. So I'll say, "This is at 1.15." Or, you know, this is at, you know, it's, it's between the first and second diamond. I'll say 1.7, you know, you know, so we can, we can find two.

• 35:05Neil deGrasse Tyson?

  Yeah, okay.

• 35:05Speaker 03

  And, and people can learn about fractions and decimals that way, too.

• 35:08Neil deGrasse Tyson?

  Uh, we, we gotta actually land this plane, as we try to do. Let me offer some final reflective comments. Any astrophysicist older than 50, never challenge them to pool. Because if you're over that age, you would have visited telescopes in your day. After that, the, the, it's remote observing, because everything is done electronically now. But at telescope domes, on cloudy nights, every mountain telescope has a pool table. And on cloudy nights, you have to, you have to be on call in case the clouds part, everyone is playing pool, we are all badass. Well, we're not world-class, but we're better than, you think we're better than average.

• 35:51Neil deGrasse Tyson?

  And so this is an alert for all pool sharks out there. Watch out for astrophysicists.

• 35:56Speaker 03

  I like it.

• 35:57Neil deGrasse Tyson?

  I think a lot of people would have spent much more time paying attention in their geometry class and in their physics class, had they known about your pool tables. I'm pretty sure. So tell us, where do we find you online? We know you have, what do we, where do we find you on Facebook?

• 36:12Speaker 03

  Yeah, people want to see some videos, uh, that, that demonstrate a lot of this stuff.

• 36:16Neil deGrasse Tyson?

  I do.

• 36:16Speaker 03

  I have a Facebook, Facebook page, it's Dr. Dave Billiards. I have a YouTube channel, Dr. Dave Billiards. I have a website, uh, DrDaveBilliards.com, where I sell my book, my videos, t-shirts, all kinds of stuff. I have another website, which is probably of the most interest, it's billiards.kolo state.edu. That's, um, all free stuff. I have thousands of videos, thousands of articles, or hundreds of articles I've written for Billion Magazine.

• 36:39Neil deGrasse Tyson?

  Okay, so that's your academic pivot point for your, for your life's output. Very good, very good. All right, we're actually done here. David, it's great to have you on and I'm always pleased to learn that they're complete experts in things that we don't otherwise think would have experts or would even deserve experts. And there you are bringing the science down to earth. Thank you Neil. And that's what we try to, how we try to roll here on StarTalk. Gary, Chuck, always good to have you. And Chuck, now I understand Chuck, why you keep asking for a raise. It's to get out of debt. We'll visit you in prison Chuck, all right? All right guys, I'm Neil deGrasse Tyson, signing off for StarTalk as always, keep looking up.