#ICYMI - Cosmic Queries: Sports Physics Trivia, with Charles Liu

In case you missed this episode on the Playing with Science channel… Football on Mars, tricky cricket physics, curving curling rocks, and more – Hosts Gary O’Reilly and Chuck Nice sit down with astrophysicist Charles Liu to answer fan-submitted Cosmic Queries that span across the sporting world. Photo Credit: Xiaphias [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons.

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

• 0:09Gary O'Reilly?

  I'm Gary O'Reilly.

• 0:10Chuck Nice?

  And I'm Chuck Nice.

• 0:11Gary O'Reilly?

  And this is Playing with Science. Today, you listeners will be the stars of the show. Yes, we've opened up the cosmos for your particular queries. Call it office hours if you wish, but this is going to be our show. Of course, it's going to be ladled with science and have a bit of a sprinkling of sport.

• 0:34Chuck Nice?

  That's right.

• 0:34Gary O'Reilly?

  Who else is joining us, Chuck?

• 0:36Chuck Nice?

  And of course, when you say science, you can't say science without the one, the only, the astrophysicist who knows the most about sports of any scientist I've ever met, the one, the only Professor Dr. Charles Liu. Hey, Charles.

• 0:53Charles Liu?

  Hey. Hi, Chuck. Hi, Gary. You are too kind in your introduction. There are many, many people who know much more about sports than I.

• 0:59Chuck Nice?

  Yeah.

• 1:00Charles Liu?

  But I am very happy to be here.

• 1:01Chuck Nice?

  But not on the level that you know sports and not the way you're able to relate sports to science, my friend. I'm sorry. I mean, not even our fearless leader, Dr Neil deGrasse Tyson, I would say, has the breadth of knowledge of all sports that you do, you know?

• 1:21Charles Liu?

  Well, I humbly live to serve and I hope that I would be able to answer the questions from our excellent audience. As always, they bring good stumpers to the table.

• 1:31Gary O'Reilly?

  They do, and we're opening up their inquiring minds. And here we go. This one caught my eye straight away. This is from Joe Anderson 2429 on Instagram. "The waves are affected by the moon." He sounds English here because he goes, "The waves are affected by the moon, right? What if the Earth had another moon? How would adding another moon to Earth impact sports?" I'm guessing surfing, sailing. That's one, I've not thought about that before, but over to you, Professor.

• 2:00Chuck Nice?

  Yeah, I mean, yeah.

• 2:02Charles Liu?

  It is a great question. Yes, the reason that the moon affects the waves, right? Is because the moon's gravity has a subtle effect that's stronger when in on the part of the earth closer to the moon than away from the moon.

• 2:16Gary O'Reilly?

  Uh huh.

• 2:16Charles Liu?

  Now, solid rock doesn't really feel that so much, but liquids like water on the surfaces of, say, lakes, rivers, or most likely the ocean, will actually move a little bit toward the moon. And the center of the earth moves a little closer to the moon than the backside. So you basically have an elongation of the of the earth. The liquid pops out and then backs in and it's just kind of this undulating motion of the waves back and forth. And that's because we're the moon. So if the moon is here, then the tides are strongest along the axis and it just kind of follows this way. So imagine you have two moons. In that case, you have a moon here and a moon here, and if it goes around, it's gonna cause even more pulling.

• 2:59Charles Liu?

  Under the right circumstances, you could get double the wave action, right? So maybe if you were a surfer and you're looking for that monster wave, you would getting a seriously double monster wave, right? Whereas at other times, depending on the positions of the moon, they might actually help counteract each other's motions. So that you'll have a reduced amount of moon action. So one way or another, the tides can be strongly affected and it has all to do with the relative positions of the moons and the earth at any given time to where you are.

• 3:32Gary O'Reilly?

  Oh, wow. So the relate the the relationship in terms of their orbit around the earth would be critical as to which way that that takes place?

• 3:41Charles Liu?

  That's exactly right.

• 3:42Chuck Nice?

  Would it also have to depend on the size of the moon itself? I mean, you would have to take that into consideration too, right?

• 3:48Charles Liu?

  Question. The size of the moon itself is not as important as the mass of the moon.

• 3:54Chuck Nice?

  That's what I meant. I'm sorry. See, this is why you're a scientist, because you actually are specific enough to say mass, because there are lots of things with great size, but not great mass.

• 4:06Charles Liu?

  Right. You can imagine some basketball players with tremendous size, but they do not have as much mass as your perhaps smaller, more compact football player.

• 4:15Chuck Nice?

  Right. Okay. Yeah.

• 4:16Charles Liu?

  Yes, so a small moon like with a small size but made up primarily of something heavy like metals might actually have more mass than a larger moon that's made up of primarily something like ice or rock.

• 4:30Chuck Nice?

  Or even our own moon, which by the way is not made up of metals.

• 4:35Charles Liu?

  That's right, it has mostly rock.

• 4:37Chuck Nice?

  Mostly rock. Cheese. And cheese. Oh, okay. I believe it's Gruyere.

• 4:41Charles Liu?

  It's the good stuff. The distance between the moon and the earth also matters. So both mass and distance and then position relative to the earth and where you are. All of that puts a really interesting tug on the various oceans and rivers and seas and so forth.

• 5:00Chuck Nice?

  Cool, man. Hopefully Joe Anderson's got the answer he was looking for. Yeah, well, and listen, if he didn't get it out of that, then, you know, Joe's just being a dick. No, I'm just. I think we lost a listener. Maybe just one. Maybe more. No, Joe, you know, we love you, and that's a great question. And by the way, that's a really great question. Look how, look how fascinating that was. So he's a thinking man, and we like that, Joe. Did I kiss his butt enough? You did. Okay, good. All right, this is, uh, Hamid Isham from Facebook. And, um, I only say that because he spelled it out actually phonetically. He must have known that I was gonna read this. Hamid Isham says this.

• 5:43Chuck Nice?

  What if a football player kicked the ball with a strong kick on the moon? Will it stop at a certain level? Or will it continue to climb up out of the atmosphere, uh, and on forever? Signed, Hamid from Egypt. Uh, now, the one thing I will say with that question that might be a little suspect is, uh, he says atmosphere with respect to the moon. So could that even be the case?

• 6:16Charles Liu?

  Right. The moon does not have an atmosphere. Uh, very occasionally, some amount of, uh, volatile material may vaporize from the surface and temporarily create a little bit of a vapor. But it doesn't have a standing atmosphere and that's something that's very important. So Ahmed, the first thing that you should realize is that without an atmosphere on the moon, if you kick the ball, it won't curve. You can't make it spin in such a way that the ball will either go toward the sidelines, for example, or say do some sort of weird thing against the wind and so on.

• 6:52Chuck Nice?

  So wait a minute, are you, so the end over end of a football on the kickoff that we see, that, that, that flipping motion, that's caused by, we'll call it resistance? That's caused by the air resistance?

• 7:06Charles Liu?

  It's originally caused by the kick.

• 7:08Chuck Nice?

  Okay.

• 7:09Charles Liu?

  It's caused by the kick. And then after that, when you have the end over end, or when you have a flipping sort of turning position, then the air will affect it to change either its direction or its pace or things like that.

• 7:21Chuck Nice?

  Okay, go ahead.

• 7:22Charles Liu?

  Uh, yeah, one of the greatest punts in the history of all time college football was Harvard versus Yale in 1987. And it was a 40 mile an hour wind going in one direction. And Yale was on fourth down, needed to punt, and they were gonna wait till the third quarter ended to switch over to the fourth quarter, and then they could kick with the wind. And the Harvard coach called timeout with only a few seconds left in the third quarter, forcing Yale to kick into the wind. And the ball went like this, and then like that. The total net yardage, because the wind just pushed it all the way back, was nine yards.

• 8:06Chuck Nice?

  Wow.

• 8:07Charles Liu?

  A beautiful nine yard punt, which then led to Harvard scoring the winning touchdown in the fourth quarter, and it was a glorious victory. But nobody knows it because it's Harvard-Yale. Those guys aren't playing in the NFL anymore. Anyway, it's a great story to tell you how important atmosphere is in football. But on the moon, there is no atmosphere. So the ball can go end over end, it can spin however it wants, but it will still just go in a parabola up and down. And the primary question which Ahmed, you asked, would it go on forever?

• 8:44Charles Liu?

  No, it would not. The answer is that the ball would come back down because the moon still does have surface gravity. It's only one-sixth the level that of the earth. But what that means, it'll slow things down one-sixth the speed. It'll take six times longer for the ball to land than it would be on earth, which means that it should travel six times farther before it reaches the surface of the moon compared with being kicked on the surface of the earth. But it will come back down again.

• 9:14Chuck Nice?

  Wow.

• 9:15Gary O'Reilly?

  Another comprehensive answer with the sprinkling of Harvard and Yale.

• 9:18Chuck Nice?

  But of course you, sir, have the boorish manners of a Yale-ee.

• 9:23Gary O'Reilly?

  However, there was a... Didn't... Did he not Ryan Fitzpatrick, the former Jet, now Tampa Bay Buccaneer quarterback?

• 9:30Chuck Nice?

  Quarterback of the Buccaneers.

• 9:31Charles Liu?

  He's really kicking. Yeah, he's rocking and rolling down there right now.

• 9:36Chuck Nice?

  Yeah, he's rocking and rolling, and I believe he is a Harvard man. Yeah, smart guy, by the way, you know? And who else is going to Harvard? Is it, um, who is it? Is it Urschel? Who's, who, John Urschel, right?

• 9:49Charles Liu?

  Oh, John Urschel, who played on the offensive line for the Baltimore Ravens.

• 9:54Chuck Nice?

  For the Ravens, but isn't he going back? No, he's going to MIT. I'm sorry, he's going to MIT.

• 9:59Charles Liu?

  Either he is about to get his doctorate or is getting his doctorate at MIT in pure math.

• 10:05Chuck Nice?

  Correct, pure math.

• 10:06Charles Liu?

  Pretty impressive stuff. I've read, I've read a couple of his papers. He really knows what's going on.

• 10:10Chuck Nice?

  Yeah, he's, this isn't a hobby for him.

• 10:12Charles Liu?

  It's not just blocking and tackling. This guy's all out on, on the math.

• 10:17Chuck Nice?

  Isn't it cool that these guys are like, you know, dedicated to academics and academia, and yet at the same time, they're able to play professional football?

• 10:32Gary O'Reilly?

  Yeah. It scares me. Guys who are built like tanks, who hit like tanks are very super intelligent.

• 10:41Chuck Nice?

  Yeah.

• 10:42Gary O'Reilly?

  Scary people.

• 10:43Chuck Nice?

  That is a scary thought.

• 10:44Charles Liu?

  You gotta hire them for think tanks, Gary. That's what you gotta do.

• 10:47Chuck Nice?

  A think tank.

• 10:48Gary O'Reilly?

  Oh, Charles, that's fabulous.

• 10:50Chuck Nice?

  I see what you did there, Charles. I see what you did there. Think tank.

• 10:53Gary O'Reilly?

  I'm in awe of that one.

• 10:54Chuck Nice?

  I gotta tell you something. They, this is why you're an astrophysicist, sir.

• 10:59Charles Liu?

  It's why I'm not a comedian.

• 11:00Gary O'Reilly?

  Another, another Wright boy, Wright spelt with a W, just in case anyone was worrying.

• 11:07Gary O'Reilly?

  On Instagram, "How hard would you have to kick a football for said ball to reach orbital velocity and orbit Pluto?"

• 11:15Chuck Nice?

  Oh my god.

• 11:16Gary O'Reilly?

  Kane from Kamloops, British Columbia. And there's a hashtag Pluto is a planet, so just as well Neil's not here.

• 11:22Chuck Nice?

  Interesting.

• 11:23Charles Liu?

  Wow.

• 11:24Chuck Nice?

  So what is, what is the escape velocity for a football?

• 11:28Charles Liu?

  Well, the escape velocity for any object is the same, regardless of whether it's a football, or a golf ball, or an elephant. Okay, but I haven't calculated the escape velocity of Pluto yet. That's not something that normally sits in my head. But there's a fairly well-known calculated formula for the escape velocity, which is the square root of 2 times the gravitational constant of the universe, G, times the mass of Pluto, divided by the radius of Pluto. So the square root of 2 G M over R, where you plug in the mass and the radius of Pluto respectively, will give you the escape velocity on Pluto. All right.

• 12:13Charles Liu?

  Now, here on Earth, the escape velocity at the surface of the Earth is something like 20, 20-something thousand miles per hour. Pluto is significantly smaller and significantly lower mass than the Earth. In fact, significantly lower mass than the moon itself, which is part of the reason why our distinguished friend Neil argues for its demotion to below planetary status. But that's a discussion for another time.

• 12:43Chuck Nice?

  Right, yes. We don't want to be controversial.

• 12:47Charles Liu?

  It's probably less than 20,000 miles per hour, and I just don't know exactly how much it is. But it's not, say, 10 miles an hour, but it's definitely not 10,000 either. It's somewhere in between.

• 13:00Chuck Nice?

  Okay, cool. So now, escape velocity puts you into orbit. Once you achieve that, though...

• 13:08Charles Liu?

  Escape velocity puts you beyond orbit.

• 13:10Chuck Nice?

  Beyond orbit, I'm sorry.

• 13:12Charles Liu?

  Orbital velocity.

• 13:13Chuck Nice?

  That's what I'm saying. All right. So escape, escape velocity puts you... Out of orbit.

• 13:19Charles Liu?

  Right.

• 13:19Chuck Nice?

  And allows you to just now you're in now you're headed out into space.

• 13:26Charles Liu?

  That's right. You're gone forever.

• 13:27Chuck Nice?

  Okay, so now, because space is a vacuum and you're not in, let's say you're not in, and most space is mostly empty, you're not in, let's say you don't encounter anything, would you just keep going at that speed forever?

• 13:43Charles Liu?

  Yes, until you interact with something else.

• 13:45Chuck Nice?

  Right.

• 13:46Charles Liu?

  And and you bring up an excellent point because the question was indeed, uh, not just, uh, for Pluto to, uh, for the football to escape Pluto's gravity, but to orbit around Pluto.

• 13:56Chuck Nice?

  Right?

• 13:56Charles Liu?

  And so I'm glad you made that distinction between orbital velocity and escape velocity. Turns out orbital velocity is about seventy one percent that of escape velocity.

• 14:07Chuck Nice?

  Gotcha.

• 14:07Charles Liu?

  So it's a little bit slower, okay, uh, but it's still a very high speed.

• 14:12Chuck Nice?

  Right, and basically the answer is no, no matter if it's orbital velocity or escape velocity, you have a job with any NFL team on Earth.

• 14:25Charles Liu?

  If you can.

• 14:25Chuck Nice?

  Or pretty much any, any football or soccer team too, right?

• 14:28Gary O'Reilly?

  Thing is, once you've got a leg like that, it's controlling it.

• 14:32Chuck Nice?

  Right, I guess so, yeah.

• 14:33Gary O'Reilly?

  Cause you'd be just kicking it through the stadium.

• 14:36Chuck Nice?

  But would you really need to control it? I mean, it's just like.

• 14:38Charles Liu?

  That's true. You just kick the ball, right? Who needs to control? Because no one's gonna stand in the way.

• 14:43Chuck Nice?

  Exactly, nobody's gonna, right.

• 14:44Charles Liu?

  Take your leg off.

• 14:45Chuck Nice?

  A goalie is going to stop a, a fifteen thousand mile an hour.

• 14:50Gary O'Reilly?

  No one's gonna sit near the goal. Could you imagine if it was a soccer team?

• 14:53Chuck Nice?

  Right.

• 14:54Gary O'Reilly?

  No one's, no fans are gonna sit behind, around the goal because all of a sudden this thing's coming at ten plus thousand miles an hour. You know what? I'm not stopping that. It's gonna vaporize me.

• 15:03Chuck Nice?

  All of a sudden soccer is the coolest sport in the world to me right now. This is amazing. Uh, let me ask you this. I'm no, I know we're running out of time for our first segment, but this is so fascinating, man, when we do these little thought experiments. Let's say, because it's, it's an actual football or a soccer ball, either one, and you do reach that kind of velocity, would the ball just burn up because of the friction of the air before it does anything? Would that be really what would happen?

• 15:31Charles Liu?

  It would burn up. There would be no question about it. I just don't know how fast it would burn up. Okay. Right, because I'd have to make that calculation as well. It is true that the viscosity of the atmosphere will cause this thing to slow down, and as it slows, it also heats up. But I don't know if it will burst into flame in a few feet, or if it might take a few miles or some other distance. I'd have to do that calculation.

• 15:53Chuck Nice?

  Wow, that is so cool!

• 15:55Gary O'Reilly?

  See, the only, the only thing that would make that, uh, an unnecessary calculation is the fact you've put so much energy through a soccer ball or a football, it would explode. Surely.

• 16:05Charles Liu?

  Yeah.

• 16:06Gary O'Reilly?

  It just wouldn't be able to contain itself, and before it gets to combust, it would just go.

• 16:09Charles Liu?

  That's right. Right, so. The, the typical football probably can't take more than, uh, a hundred pounds per square inch from the interior before it blows up, right? Maybe fifty.

• 16:19Gary O'Reilly?

  Yeah.

• 16:20Charles Liu?

  Uh, in a regulation ball is much lower than that. So, if you're going to kick it, that means you have to put from the outside, and you're going to compress that ball, that the interior pressure will substantially exceed a hundred PSI or even more, which would probably cause it to explode first. That's, that's to score one point for Gary.

• 16:38Chuck Nice?

  But what you could do, what you could do is shoot it from a railgun, right?

• 16:42Gary O'Reilly?

  Here we go.

• 16:43Charles Liu?

  Oh, sure.

• 16:44Chuck Nice?

  Yeah, you could shoot it from a railgun and watch it burn up. I just want this bad boy to burn up, is all I'm saying.

• 16:49Charles Liu?

  The problem with the railgun is that it's not mag, it, it usually requires a magnetic push.

• 16:54Gary O'Reilly?

  Right.

• 16:54Charles Liu?

  Right? And, and soccer balls, footballs, don't have a lot of metal in them, so you can't exactly continue to accelerate them using electromagnetic force.

• 17:02Gary O'Reilly?

  And plus, the, the agent for the, the railgun needs a new, when you negotiate a contract.

• 17:07Chuck Nice?

  Yes. And then. Don't worry, I have a super lightweight, um, magnetic, uh, thread that I've actually put through the entire football so that I can get it up to that speed and watch it burn up, baby.

• 17:21Charles Liu?

  Totally, I totally would want to see that.

• 17:23Chuck Nice?

  Burn, baby, burn!

• 17:24Gary O'Reilly?

  Such a science villain, aren't you? You are a science villain!

• 17:28Chuck Nice?

  This is why I'm not a scientist, because the universe knew that if it gave me this type of knowledge, I would definitely use it for bad and not for good.

• 17:39Charles Liu?

  I am sure there are many excellent scientists who would love to fire a soccer ball fast enough to watch it burn up in the air. That would be a true science thing to do, so.

• 17:48Gary O'Reilly?

  And you're not allowed to meet them.

• 17:51Gary O'Reilly?

  Right, we are going to take a break. I'm gonna have to talk to Chuck during the break and kind of talk him off the ledge of badness and bring him back to the good and the light. When we come back, more Sports Physics 101 with the magnificent Professor Charles Liu. Stick around.

• 18:12Gary O'Reilly?

  Welcome back to Playing with Science. We've taken sport into the universe and off-world, as it were, and Professor Charles Liu has given us some most brilliant answers. We're gonna kind of bring it back down to Earth if we can. We've had so many fabulous questions. And Jennifer Meijam on Facebook, if I've pronounced that incorrectly, I apologize. How long, and this is theoretically speaking, would it take Usain Bolt to run around the Earth?

• 18:42Charles Liu?

  Oh, what a great question. Usain Bolt, of course, the fastest sprinter in the world. If you sort of pick up his top speed as he's running 100 metres, is somewhere between 27 and 28 miles per hour.

• 18:58Gary O'Reilly?

  Which is ridiculously quick.

• 19:00Charles Liu?

  Yeah, it's just like 40-something kilometres per hour. And so that's really good. Now, the radius of the Earth is just under 8,000 miles, which means that its circumference at the equator is about 24,000 miles. Okay, so if he's running at that top speed, let's say 28 miles per hour, going 24,000 miles would take him a little under 1,000 hours, which I guess at 24 hours per day brings you out around several weeks.

• 19:32Chuck Nice?

  Wow, that's pretty impressive for a human being to be able to do that.

• 19:37Charles Liu?

  Right, but remember, he can only keep up this pace for 10 seconds at a time, right? So he's gonna run that fast, then he's gonna walk it off, take it easy, take a break, breathe, whatever, whatever, and then run that fast again, then breathe, then take it easy. So you gotta build in all that extra rest time.

• 19:52Gary O'Reilly?

  And then take out the terrain.

• 19:53Chuck Nice?

  So the real answer is 200 years.

• 19:56Charles Liu?

  It could be a little while. Remember that near the equator, Mount Kilimanjaro is like more than 19,000 feet, so he's gonna have to do a little bit of altitude trek as well if he runs around there. So he's gotta stay in the lowlands.

• 20:09Chuck Nice?

  So now, what about the Flash? The real Usain Bolt? Okay? Do we know what the top speed of the Flash is?

• 20:17Charles Liu?

  Well, it keeps changing depending on what the comic book writers decide. There was a period of time where the Flash could literally go faster than the speed of light.

• 20:26Chuck Nice?

  Right.

• 20:27Charles Liu?

  I think that might be the case in certain universes right now. There was another period of time when the Flash could only run about the speed of sound, maybe a little bit faster. That was like in the 1980s or something like that. So it really depends on who you're talking about.

• 20:42Chuck Nice?

  He was lazy back in the 80s.

• 20:43Gary O'Reilly?

  Yeah.

• 20:43Chuck Nice?

  He wasn't very, he was a lazy dude back in the 80s. He also gained a few pounds, so that's what did it, you know?

• 20:48Charles Liu?

  Well, it had to do with something called Crisis on Infinite Earths, where Barry Allen, the original Flash, had to sacrifice his life to save the universe. And Wally West took over. But Wally West, in his efforts to save the universe a second time or multiple times from the Anti-Monitor, he had to sacrifice some of his speed power. And then nowadays, of course, there's this thing called the Speed Force. We're getting a little bit into the fiction and out of the cosmos, but you know, this is fun stuff to talk about.

• 21:17Chuck Nice?

  Yeah. And let me ask you this, when you said the speed of sound, Flash breaking the speed of sound. If you were running at the speed of sound, okay? As a human being, all right? And let's just say that you have like, I don't know, a special suit or a little force field around you, okay? And you're running at the speed of sound. Will you make, as a human being, a sonic boom?

• 21:38Charles Liu?

  Yes, you will.

• 21:39Chuck Nice?

  On the ground as you run?

• 21:40Charles Liu?

  That's right. You have this thing, yes. What you're doing, sonic boom is happening, you're creating basically a shock wave, right? You have the air in front of you and you're running, you're basically compressing the air, so the air starts bending around you. When you pop through that barrier, what we call the shock front, then you literally create that sonic boom in kind of a wake behind you. So you zip by and there's

• 22:03Gary O'Reilly?

  This is again, another example of why you're not allowed to be good at science. You wanna, you wanna run past people you don't like and create sonic booms outside their house and break their windows?

• 22:13Chuck Nice?

  That's why, that's why I own a Harley right now. Same reason.

• 22:20Gary O'Reilly?

  Kettlebells and queso on Instagram. Now you know who you are. So how heavy of a kettleball can Chuck swing? And does he know what a kettleball is?

• 22:35Chuck Nice?

  Wow, I don't know. I don't know why he's gotta diss me like that, man. But you know, I actually do have an answer to both of them. One is, I do know what a kettlebell is. And two, how heavy of a one can I swing? Whatever it is that will break your foot when I drop it on it?

• 23:04Gary O'Reilly?

  That may not be the answer you wanted, but possibly the answer you deserved.

• 23:09Chuck Nice?

  Oh, that was great, man.

• 23:12Gary O'Reilly?

  Thank you for cheering Chuck up.

• 23:14Chuck Nice?

  Yeah, man, that actually made my day. I'm happy. All right, here we go. This is Tony, Ellie738 from Instagram. He says, how does the rock in curling turn by the broom action?

• 23:29Charles Liu?

  Oh, great question. Great, great question. See, the path that the little rock goes in curling is not a perfectly smooth sheet of ice.

• 23:41Gary O'Reilly?

  That's right.

• 23:41Charles Liu?

  There's rough bits on the ice. Shavings, almost like a smooth slushies.

• 23:49Gary O'Reilly?

  They make it unlike a hockey rink.

• 23:52Chuck Nice?

  Right.

• 23:52Gary O'Reilly?

  They make it with so stippled on the top.

• 23:55Charles Liu?

  That's right.

• 23:55Gary O'Reilly?

  And that's where the brushes come in.

• 23:56Chuck Nice?

  Like pills on a sweater.

• 23:58Gary O'Reilly?

  Yeah.

• 23:59Charles Liu?

  Kind of, yeah. But they're stiff and they're hard. And so over time, when the rock slides down, when it touches those things, it'll cause whatever spin you've put on the rock to either magnify or decrease. And this causes the changing of the direction. When the broom, or the sweepers, I guess, are using the broom, they're getting rid of, wearing down those stippled, or the other non-smooth environments, which allows the smoothness to take over as opposed to the curliness and the stippledness. Uh, that's a great word, by the way, Gary, stippled. That is something we should use more often in the English language.

• 24:42Gary O'Reilly?

  Yes, there are some great words in the English language.

• 24:45Charles Liu?

  Right. And so the brooms will allow the rock to go farther.

• 24:50Gary O'Reilly?

  What are you giggling about? Sorry, sorry, Professor. What are you giggling about?

• 24:53Chuck Nice?

  Because it's like, there's some great words in the English language, and by that, I mean the British language.

• 25:00Gary O'Reilly?

  Yes, it is British, and I'll see you stipple and raise you rummage.

• 25:04Chuck Nice?

  Rummage? What a wonderful word.

• 25:06Gary O'Reilly?

  It's a fabulous word.

• 25:07Chuck Nice?

  Yes, rummaging through my past.

• 25:09Gary O'Reilly?

  Yes.

• 25:10Chuck Nice?

  Hmm, stop rummaging through my past, damn it.

• 25:12Gary O'Reilly?

  Completely science and sport unrelated, but.

• 25:15Chuck Nice?

  Yeah, go ahead. Sorry, Professor.

• 25:17Charles Liu?

  That's okay. No, no, no. I like my, I like me a good rummage sale once in a while.

• 25:22Gary O'Reilly?

  Yes.

• 25:23Charles Liu?

  Yeah. So, so the brooms basically make it so that the rocks can go farther without curling as much, because it's reduced the amount of friction between the rock and the ice.

• 25:33Chuck Nice?

  Sweet. That actually makes, that makes sense.

• 25:37Gary O'Reilly?

  I mean, when we did the show back in the winter on curling.

• 25:40Chuck Nice?

  Yeah.

• 25:41Gary O'Reilly?

  The science, on the initial viewing of curling, you're thinking, meh. And then you drill down deeper and you're thinking.

• 25:48Chuck Nice?

  What an awesome, awesome sport.

• 25:50Gary O'Reilly?

  I can see why so many people have latched on to curling and they get addicted every four years.

• 25:55Chuck Nice?

  Absolutely. I'm missing it right now. I can't tell you how many nights during the Winter Olympics I was up at 3:00 AM drunk watching curling. It was amazing.

• 26:04Charles Liu?

  Look, there are two things about curling that are really great for me. One is the pose that the person strikes as is pushing the rock.

• 26:12Gary O'Reilly?

  All right, yep.

• 26:13Charles Liu?

  Beautiful balletic structure. I think you should get style points for that in future Olympics. And then the second thing which I love about curling is the yelling. It's like, hard, hard, hard, hard. I mean, what other sport has that kind of verbal interjection? Right? You should get style points for how well you shout at your friends as well.

• 26:40Chuck Nice?

  I like it. I like it. And I'm resisting. Every single inclination in my body and soul.

• 26:50Charles Liu?

  To comment?

• 26:51Chuck Nice?

  Not comment on screaming hard, hard, hard.

• 26:56Gary O'Reilly?

  Please continue to resist all temptation. Please.

• 27:00Charles Liu?

  Chuck, come on, man.

• 27:03Gary O'Reilly?

  All right. Professor, there are things we know we can ask for and things that we know we shouldn't ask for. And I think that it was the latter because his mind is just going to wander straight to that point. All right, here we go. This is from Chris Tuckadick. I know. This has been set up, hasn't it, for me? Really?

• 27:23Charles Liu?

  Your, your timing is perfect, sir.

• 27:25Gary O'Reilly?

  Yes. Um, it might take about five minutes before Chuck stops giggling. It might not. It might even take longer. Um. Damn, Chuck. In rugby union or rugby league, you have to pass the ball to your teammate. Stop giggling, who is on, who is in an onside position, which is behind where the ball carrier passes from. Is it possible for a player running at full speed to pass the ball to a teammate a meter or two behind and in line with him and the ball not go forward relative to where it was passed from? This happens all the time and sometimes it is penalized, sometimes it is not. So, so professor, moving forward while passing the ball backwards seems really quite strange.

• 28:09Gary O'Reilly?

  And it's not a surprise the British invented rugby.

• 28:14Charles Liu?

  Well, this is a good question. I don't know the exact rule, Gary. When is it that the person who receives the backwards pass has to be behind where the person who passed it is at the moment of reception? Or at the moment of departure from the tosser?

• 28:31Gary O'Reilly?

  Um, I think the ball itself has to travel backwards. So you would imagine he has to be in a position behind the thrower, the passer in,

• 28:41Charles Liu?

  Right.

• 28:41Gary O'Reilly?

  On catching it.

• 28:43Charles Liu?

  Yeah, this is where, this is where something called Galilean relativity comes into effect. Okay, if you're moving at 10 miles per hour.

• 28:51Chuck Nice?

  Mm hmm.

• 28:51Charles Liu?

  Um, should I switch to metric because we're talking rugby?

• 28:55Chuck Nice?

  No, no, no, the British invented yards. We're quite happy.

• 28:58Charles Liu?

  Okay, if you're running this way at 10 miles per hour and your, your friend is running behind you also at 10 miles an hour. If you're traveling together, even though you are both going 10 relative to one another, you're traveling at zero. Which means if you were to pass it backwards, then he'd be right there as if you were there. When you tossed the ball, the ball would have your 10 miles an hour added to its backward motion. So it'd actually be still moving forward, even though relative to the two of you, it's moving backwards. Okay, so let's say if you were moving at 10 miles per hour, but the person has to catch the ball behind the place where you passed it originally. That's back here.

• 29:38Charles Liu?

  Then in that case, you'd have to pass it harder than 10 miles an hour, maybe 11 or 12 miles an hour backwards in order for your mate to receive the ball before uh he reaches the place where you have just tossed it.

• 29:52Chuck Nice?

  Right.

• 29:52Charles Liu?

  So the answer to the question is yes, it's complicated and you definitely have to toss it backwards. But if you don't toss it backwards far enough, let's say you're running at 10 miles per hour and you toss it backwards at 8 miles per hour. The ball's still moving forward as far as the referee is concerned at 2 miles per hour.

• 30:07Chuck Nice?

  Right, and, and what will happen is that person will end up in the place beyond whatever point and be penalized. Even though the ball was actually passed backwards.

• 30:17Charles Liu?

  That can happen.

• 30:18Chuck Nice?

  Yeah.

• 30:19Charles Liu?

  It's a real judgment call depending on what the referee decides. Uh, I, I, I've seen enough rugby. I will have not played it myself. I value my, my health a little bit too much.

• 30:28Chuck Nice?

  Yeah, the big, the big guys hit hard. Let me just say that.

• 30:31Charles Liu?

  So I'm told, yes, but uh, watching it is, is a fascinating game, you know.

• 30:36Chuck Nice?

  Great game to watch.

• 30:37Charles Liu?

  A lot of really interesting stuff.

• 30:39Chuck Nice?

  This next question is definitely for you. Um, the.

• 30:48Chuck Nice?

  The reluctant artist wants to know this from Instagram. Please, could you explain the physics behind the reverse swing of the cricket ball? What? First of all, what is the reverse swing of a cricket ball? Okay, I have to tell you, we're gonna have to do a cricket show at some point, just so that I can know what the hell it is. Because all I know is that there are big time ads for cricket on the subway in New York City. And this may be the only city in America, outside of perhaps Michigan, where cricket is advertised. And what it, first of all, what is a reverse swing?

• 31:31Charles Liu?

  Okay.

• 31:31Chuck Nice?

  Secondly, what is cricket?

• 31:35Gary O'Reilly?

  Professor, all yours, and I'll do my best to pick up some things.

• 31:39Charles Liu?

  More than a sport, it is a lifestyle. It is a true way of thinking of the universe. So I respect all those who live by cricket. The reverse swing is a little bit less metaphysical than that. I'll use a baseball analogy, right? A baseball has two seams. And so when the pitcher throws the baseball, depending on how the seams are moving when it leaves the pitcher's hand, the ball can curve, right? As it interacts with the atmosphere. Now, the cricket ball has one seam down the middle.

• 32:14Gary O'Reilly?

  Yep.

• 32:14Charles Liu?

  And when the cricket person does the equivalent of pitching the ball to what the equivalent person of the batter is, the ball bounces off the ground. And then the ball gets smacked by this wooden paddle, as you know, and heads out into the field. Now, this ball is used over and over again.

• 32:36Gary O'Reilly?

  Yep.

• 32:37Charles Liu?

  Unlike in baseball, where if the ball gets hit and goes far away and the umpire decides the ball has been deformed or been damaged by the bat, then it gets tossed out and a fresh ball is put in. That cricket ball is reused. And so, some people figured out...

• 32:55Charles Liu?

  That if they could make sure that every time they pitched the cricket ball, they only got the side, one side damaged. And then the other side, they tried to keep smooth and polish it as much as possible. Then after thirty or forty such pitches called overs, right?

• 33:15Gary O'Reilly?

  Yep.

• 33:16Charles Liu?

  The ball will start looking very asymmetric. One side will be roughed up and beat up, the other side will be smoothed and polished. And you've got the leather seam in the middle.

• 33:25Gary O'Reilly?

  That's, that, you just described my marriage.

• 33:31Charles Liu?

  Okay, marriage or otherwise. Imagine that ball, now the person who's doing the equivalent of pitching of this ball.

• 33:38Gary O'Reilly?

  Yep.

• 33:38Charles Liu?

  He can throw the ball down and make it look like it's gonna bounce left. But because he uses exactly the side of the ball that is damaged as opposed to polished to hit the ground first, instead of the ball bouncing and going left as you might expect, it'll bounce and go to the right. That's the reverse swing and that causes batters to get fouled up.

• 34:04Gary O'Reilly?

  Wow. So the thing here Chuck, the seam that Professor Lou was talking about, you would normally place your fingers either side. So the seam is in the middle. But now you would come over maybe like a twenty degree angle over the seam. And if you watched cricket for long enough, when they wear white, all white, the players will have a red scuff down one thigh. Cause that's the, that's the bowler, the pitcher in this cricket. He's shining it up. One side and they've, they have learned and the Pakistanis, national, and their love for cricket is every bit as strong as the Indians. And they really brought this art, and it's an art form.

• 34:46Gary O'Reilly?

  They brought this forward and they've been awesome at it and they just befuddled, another lovely word, right? For, for, for, ah, for so many years and now everybody is thinking how they do it. Because there's other things, if you've got some moisture in the atmosphere, they use everything, plus the fact, unlike baseball, you use the ground. To make things happen.

• 35:09Chuck Nice?

  Right.

• 35:10Gary O'Reilly?

  And if the ground is hard enough, if it's not, if it's crap, all sorts of different things. And I, I agree with, with the professor. Cricket is such a cerebral sport.

• 35:19Chuck Nice?

  Sounds awesome. I might have to check it out. However, all this talk of cricket and the way that they damage their balls has given me a new um phrase for baseball. Baseball, watch us. Our balls are always fresh.

• 35:35Gary O'Reilly?

  And on that note, we'll take a break. Um, yes. This has been Playing with Science and I'm not sure if we're still on the air. However, if we're still on the air when we come back after this break, it'll be great because there'll be more from Professor Charles Lu and Chuck will be on the naughty step for about the next six weeks. See you shortly.

• 35:57Gary O'Reilly?

  Welcome back to Playing with Science and your cosmic queries, your inquiring minds have opened up a whole Pandora's box, all full of questions and we have the perfect person to answer them for you. Yes, Professor Charles Lu. And we'll be looking now Chuck at the perfect throw.

• 36:14Chuck Nice?

  Ooh.

• 36:15Gary O'Reilly?

  Question number one for you.

• 36:17Chuck Nice?

  The perfect throw. Um, Will J, uh, which is Will in the third, Will in third, is uh, actually, uh, he's a Patreon patron and therefore, uh, we will, you know, when you support us on Patreon, we like to give you priority because you give us money. All right?

• 36:32Gary O'Reilly?

  Thank you.

• 36:33Chuck Nice?

  Also like my marriage. Um, from a physics standpoint, he says.

• 36:39Gary O'Reilly?

  Focus, focus.

• 36:40Chuck Nice?

  My wife is gonna kill me for that one.

• 36:42Gary O'Reilly?

  Oh, yeah.

• 36:43Chuck Nice?

  Can we edit that, please?

• 36:47Chuck Nice?

  Oh, God, here we go. Uh, he says, from a physics standpoint, when I go bowling, which is about once a year at the most, hey, thanks for that little insight into your life there, Will J, um, should I go for a lighter ball that I can throw faster or a ball with more mass that I can send down slowly? Will in Houston. Interesting concept. Um, a lighter ball probably gives you the ability to throw it harder, right? But then what are the advantages of a heavy ball?

• 37:22Charles Liu?

  Well, uh, the thing that you're going for is momentum, right? The momentum of the ball is the mass of the ball multiplied by its velocity. So whether it's a heavy ball moving slower or a light ball moving faster, if you have the same momentum, the ball will transfer the same amount of impulse to the pins. So what you're looking for instead, I think, is a matter of your technique. Are you gonna spin it more? Are you gonna try to contact as many pins as possible? Are you gonna try to whack a pin particularly hard? So that you can cause it to do something funny, like knock into other pins?

• 38:01Chuck Nice?

  By the way, that's called mob bowling. When you whack a pin, hey, let me tell you, I'm sorry, but we gotta do this.

• 38:10Charles Liu?

  If, if, if it's gotta be done, it's gotta be done. Nothing personal.

• 38:13Chuck Nice?

  This is the business we've chosen.

• 38:17Charles Liu?

  So it really, I, I have found, of course, I'm not a very good bowler. Uh, but the, I have found that I prefer a heavier ball, move it more slowly. Uh, because then it is more likely that I'll be able to control its motion. Cause I don't have that arm strength, right, to push it forward. But it goes more slowly and your goal to try to get the bowling ball to contact as many pins as possible as it heads in. Right? Or to have the, each pin that gets hit, transfer as much information sideways, uh, the energy. So it'll knock out more pins off to the side. I find heavier balls going more slowly works better for me.

• 38:59Charles Liu?

  But there are friends of mine who are actually really good bowlers and they are, uh, of two minds. Some of them even use a light ball in one instance and a heavy ball in another. Let's say they have a, uh, they've taken down nine, ten, nine out of 10 pins.

• 39:14Gary O'Reilly?

  Yeah.

• 39:15Charles Liu?

  Uh, and the first hit, uh, first ball, I don't, Frank, the, what do they call them? Then your second ball, maybe because they wanna aim it more accurately. They use a lighter one and they throw it hard. So that the ball has less of a chance to start changing direction because of its contact with the lane. So maybe a combination is the right answer.

• 39:34Chuck Nice?

  Cool, man.

• 39:35Gary O'Reilly?

  Looking at it from my point of view.

• 39:36Chuck Nice?

  Uh huh.

• 39:38Gary O'Reilly?

  The heavier ball will allow me more accuracy because I'm a novice bowler.

• 39:42Chuck Nice?

  Mm hmm.

• 39:42Gary O'Reilly?

  And for the sound of it, Will is a novice bowler. If I've got a lighter ball, I'm possibly going to be trying to throw that really hard. Therefore, as you touched on, Professor, you lose the control.

• 39:53Charles Liu?

  Right. You might twist your wrist just a little bit, causing a curl and the gutter ball.

• 39:58Gary O'Reilly?

  Absolutely. So if you're a novice, possibly the heavier ball for me, thinking about it, would be a better solution. But I can't explain the physics like you do.

• 40:05Chuck Nice?

  Now, see, my take on it is when I'm bowling, what I like to do is just leave the bowling alley altogether and go get drunk because I don't need bowling as an excuse to drink.

• 40:18Gary O'Reilly?

  Okay. All right, moving on to our next question.

• 40:22Charles Liu?

  Sorry.

• 40:22Gary O'Reilly?

  Yes, Professor.

• 40:23Charles Liu?

  Do you exercise both your arms when you bowl, Chuck, or just one?

• 40:27Chuck Nice?

  Yes, I do bowl like a little child, both hands, and the ball is between my legs. And then I just push it from the line and watch it go.

• 40:36Charles Liu?

  No, I was referring to the bowling ball in one hand and the 12 ounce weight in the other.

• 40:41Chuck Nice?

  Oh, now, all you have to do is lose the bowling ball and you see what I'm doing.

• 40:48Chuck Nice?

  Awesome.

• 40:49Gary O'Reilly?

  It's a complex workout routine, Professor. Okay, next question. Maddy from Maddy Benj on Twitter. Why does spinning a baseball make it curl?

• 40:59Chuck Nice?

  Hmm, interesting.

• 41:00Charles Liu?

  Great question. Uh, just as we were talking earlier about cricket, right? The roughness of the ball or one side of the ball will cause a change in direction when it hits the ground. Uh, the same is true with the laces on a baseball. Depending on how it spins, it actually affects the airflow around it. And, uh, at first it doesn't do anything. But after some certain distance that it travels, enough turbulence builds up from the interaction with the laces to cause that ball to change direction. So we're talking about late breaks on the breaking ball or an early break on a breaking ball or a slide or slider or sinking fastball.

• 41:45Charles Liu?

  That movement depends very much on which direction the laces are spinning, whether it's going this way or that way, or whether it's kind of slowly ambling or going very fast.

• 41:55Chuck Nice?

  Let's, uh, see what Grace 22 Burrows.

• 41:58Gary O'Reilly?

  We just answered that question.

• 42:00Chuck Nice?

  Yes, we did. Yes, Grace 22 Burrows.

• 42:02Gary O'Reilly?

  Grace 22 Burrows, you've got your answer in the previous question.

• 42:07Chuck Nice?

  So, and just in case you want to hear your question read on the air, here's what your question was, Grace. How do the stitches on a baseball affect the speed at which it travels? And, and, and, yeah, it's, it's the same question, but phrase rather differently. It's, it doesn't, it affects the speed because it slows it down.

• 42:24Charles Liu?

  Right.

• 42:24Chuck Nice?

  Right.

• 42:25Charles Liu?

  And then it slows it down ever so slightly. And it's the rotation of the ball that causes it to break.

• 42:32Chuck Nice?

  There you go.

• 42:33Gary O'Reilly?

  Alrighty.

• 42:34Chuck Nice?

  Alright. So Panda 6124.

• 42:37Gary O'Reilly?

  Clever.

• 42:37Chuck Nice?

  Panda.

• 42:38Gary O'Reilly?

  Yeah.

• 42:39Chuck Nice?

  It's like, this is real dumb Panda, like Panda. It's.

• 42:44Charles Liu?

  Or it could be a Russian Panda.

• 42:47Chuck Nice?

  Ah, Panda. Ah, as in an affirmative. Yes. Uh.

• 42:55Chuck Nice?

  Uh, Panda says, is there a way to consistently ensure a perfect throw with a frisbee? Ultimate! Ultimate frisbee?

• 43:07Charles Liu?

  Ultimate is great for people like me who don't have a whole lot of arm strength and just love to watch something go a long distance in the air, leaving my hand, right? Um, the best way to ensure a perfect throw in frisbee is to do it indoors. Because you don't have any wind, right? So you have to be in some sort of indoor stadium and toss it. But I think, uh, what we're asking here are the mechanics of it. You want to release the frisbee when the frisbee is going to go straight. If you let the curve too much and you have the angle to the frisbee that's not parallel to the ground, you will wind up with a much, uh, more curling kind of throw.

• 43:48Charles Liu?

  So the perfect throw every time is pretty much make sure that you're leading forward and you let the frisbee go in the direction you're looking and that when you release, it is in the direction that you're looking as opposed to going that way or that way.

• 44:03Gary O'Reilly?

  But would it make any difference if it were backhand or forehand?

• 44:06Charles Liu?

  Ah, no, it doesn't make any difference. If you're doing forehand, you want to also make sure that you're releasing it in the direction you're looking, right? But forehand is a harder throw than the backhand, because naturally speaking, the back throw is you're more able, most of the time, not to involve the twisting motion of the wrist, and just the snapping motion of the wrist. When you're throwing this way with your forward hand, then you've got lots more motion this way, because your hand naturally has more degrees of freedom going forward. But the true experts, of course, they can control that very easily.

• 44:40Chuck Nice?

  And I was gonna say, when you throw forehand, what you're really doing is showing off.

• 44:47Charles Liu?

  Have you ever seen overhand throw?

• 44:50Chuck Nice?

  No, I cannot throw it forehand, no.

• 44:51Charles Liu?

  How about overhand throw? You guys know about overhand throws?

• 44:54Chuck Nice?

  An overhand throw on frisbee?

• 44:55Charles Liu?

  The frisbee, yes. I've seen that, when you're watching Ultimate, these are amazing.

• 45:00Chuck Nice?

  You hold it vertically?

• 45:01Charles Liu?

  Vertically. The ball, the frisbee travels vertically in the air. And it's just amazing how they can do this. I've not been able to perfect that move.

• 45:13Chuck Nice?

  That's taking showing off to a new level. That's really, that's really obnoxious.

• 45:19Chuck Nice?

  If you're throwing a frisbee vertically, and it just stays in a vertical position, that's obnoxious. You're just, you're really just showing off, man. Yeah, that's you just saying to the whole world, like, "I am not mortal." You know, that's, that's, alright, that's cool.

• 45:38Chuck Nice?

  Alright, let us move on, and, um, can we take it back to space for a second, Professor? We can. Let's take it back to space for a second, and this is, uh, Fazala Fahad, uh, on Facebook wants to know this.

• 45:57Chuck Nice?

  "How can we play football on Mars?" And I'm gonna say that's, the answer is, "Eight billion dollars." No, I'm joking.

• 46:08Charles Liu?

  Yeah.

• 46:08Chuck Nice?

  How do you play football on Mars, or how could you? And what would the difference be?

• 46:12Charles Liu?

  Well, assuming that the football players would like to breathe, you probably need to make a domed stadium, right?

• 46:18Gary O'Reilly?

  Right.

• 46:19Charles Liu?

  So you'd have some atmosphere in there.

• 46:21Chuck Nice?

  Okay.

• 46:22Charles Liu?

  And that would allow you to do all the things you would ordinarily do on Earth with a football, because you have the air at the pressure that's required for things to move. The difference is, the surface gravity on Mars is lighter. So, someone who kicks the ball upward, as we were talking about, is very similar to kicking a football on the moon. You kick the football on Mars, it will stay up a little bit longer, and then it'll fall down low. So the, all the passes will be longer, all the things will move a little bit faster.

• 46:53Chuck Nice?

  Could the players jump higher?

• 46:55Charles Liu?

  Players will be able to jump higher as well, yes.

• 46:57Gary O'Reilly?

  Alright, so it'll be an interesting game.

• 46:59Chuck Nice?

  Yeah, it would be. It sounds like a fun game.

• 47:01Charles Liu?

  Very interesting game. I would enjoy watching a football match on Mars. But, it's gonna be a while.

• 47:08Gary O'Reilly?

  Right, do we have one more question? Oh, here we are.

• 47:10Chuck Nice?

  Mm-hmm.

• 47:11Gary O'Reilly?

  Pauline Travis, Instagram, all yours, sir.

• 47:14Chuck Nice?

  Yeah, Pauline Travis says, "Not gonna read my ish anyway, unless I'm Patreon, dad gum sellouts, JK, you're awesome." Um, there you go, man. You said it wouldn't happen, but it did, okay? You said it wouldn't happen, and by the way, let's not create the moral hazard by thinking that you can get your question read by insulting us, or saying that we won't read it. Then again, who am I kidding? It'll work every time.

• 47:42Gary O'Reilly?

  I'm glad you understood that, because that went straight over my head.

• 47:45Chuck Nice?

  Oh, let me-

• 47:45Gary O'Reilly?

  Thirty-eight thousand feet.

• 47:46Chuck Nice?

  So, here's the thing, clearly, Pauline Travis is a StarTalk fan, and on StarTalk, we do Patreon questions. And if you support us on Patreon, we give your question priority. And so therefore, I always read Patreon questions first. And so he's basically saying, "You're not gonna read it because I'm not a Patreon." To which I say, "Just support us on Patreon, man, it's not that deep." Give us some money, what's the problem?

• 48:17Gary O'Reilly?

  It's okay, you can be nice.

• 48:18Chuck Nice?

  There you go, yeah.

• 48:19Gary O'Reilly?

  Right, that's our show, Chuck.

• 48:20Chuck Nice?

  That is a Chuck Lou, man. You are the best!

• 48:24Gary O'Reilly?

  Isn't he?

• 48:25Chuck Nice?

  You are the best!

• 48:26Gary O'Reilly?

  Yeah.

• 48:26Charles Liu?

  It is my pleasure. Thank you so much for having me.

• 48:29Gary O'Reilly?

  Seriously, it's our pleasure and our listeners' pleasure, Professor. It has been so good to have you on board and just for you to unlock so many of the secrets involving our listeners' questions. Brilliant. Thank you so much.

• 48:41Charles Liu?

  You're very welcome.

• 48:42Chuck Nice?

  Yeah, this was a lot of fun, man.

• 48:43Gary O'Reilly?

  Been to school again.

• 48:44Chuck Nice?

  Yep, been to school again.

• 48:45Gary O'Reilly?

  Sat in the front row of the class.

• 48:47Chuck Nice?

  There you go. Ring the kettle bell. School's out.

• 48:50Gary O'Reilly?

  That's it. That's Playing with Science and your cosmic queries. Please keep your minds inquiring and keep those questions coming in. It's been a pleasure. I've been Gary O'Reilly.

• 49:02Chuck Nice?

  And I've been Chuck Nice.

• 49:03Gary O'Reilly?

  This has been Playing with Science. We look forward to your company soon. A goodbye from Professor Charles Lewis.