Thank Goodness for Gravity
The Lexington Public Library presents "Thank Goodness for Gravity", a film about a young boy's fear of falling off the earth! Daniel meets a helpful librarian who uses the Library's Pendulum to explain the science behind the earth's rotation.
Tags: library pendulum books gravitation
Added: 2 years ago
Lexington Public Library
Thank Goodness for Gravity
[scene opens in a playground, as a young boy (with a concerned look on his face) watches a young girl on the swings go back and forth]
DANIEL: You're going too high! You could fall off!
[she continues swinging (apparently ignoring him)]
DANIEL: Uh, I wouldn't swing that high if I were you ... There's a chance your momentum could throw you right off!
[cut to Daniel watching another boy using the monkey bars]
DANIEL: The monkey bars are surprisingly dangerous ... Last year, I saw a kid lose his balance, and fall right off face-first! Blood everywhere!
[cut to Daniel watching another young girl sitting at the top of a slide]
DANIEL: I threw up nachoes all over this slide when I was six! Some people think slides are harmless, but our bodies aren't meant to move so quickly! At this kind of angle--
[the girl just smiles and starts to slide down, as an older boy enters the scene and pulls him out of her way]
STEVE: Daniel, what're you doing?
DANIEL: I'm just trying to make friends ...
STEVE: Uh, no, you're freaking people out! Just try to be normal, okay? Mom's gonna pick us up in a half an hour ... There's gotta be something around here you're not afraid of.
[he walks off, then cut to Daniel sitting on a hobby horse and slowly rocking back and forth (as a toddler standing off to the side watches him)]
[cut to Daniel getting on a turnwheel and (slowly) making it move with his feet, when another boy enters the scene and jumps on top behind him]
[he "steadies" himself, then looks up at the new kid]
DANIEL: Uh, I'm sorry ... this is only meant for one person.
TURNWHEEL BULLY: No it isn't!
DANIEL: Well, I'd like to be left alone on it ...
[the boy continues to stand there, as Daniel resumes slowly rotating the turnwheel using his feet]
TURNWHEEL BULLY: Y'know, this can go faster.
DANIEL: Yeah, but I like it at this speed, thank you.
[the boy suddenly jumps off, grabs one of the spokes and begins running around at a fast rate of speed]
TURNWHEEL BULLY: Faster!
DANIEL: What're you doing?! Ahhh! Stop, please! I'm getting dizzy!
TURNWHEEL BULLY: Come on, sissy boy! Can't take a little merry-go-round?
DANIEL: Come on!
[the boy gives the turnwheel one final push and then lets go, as Daniel continues to spin around]
DANIEL: Whoa! Whoa! I'm gonna fall! Ahh, I'm gonna fall off!
[he does eventually slide off the turnwheel and hits the ground hard, then cut to Daniel lying on the ground as his older brother stands over him]
STEVE: Daniel, that kid wasn't trying to hurt you ...
DANIEL: He was irresponsible! I wanna go home ... now!
STEVE: You cannot be my real brother, you're too afraid to go down a slide!
DANIEL: I have a weak stomach!
STEVE: You're weak, alright ...
DANIEL: I feel dizzy, can we go home?
STEVE: You never even tried to ride a ferris wheel ... a ferris wheel!
[cut to a "flashback" of Daniel standing in front of a giant ferris wheel]
DANIEL: [in voice over] I tried ...
STEVE: [in voice over] You stood in line once, big deal.
DANIEL: [in voice over] What if we got stuck at the top?
[he looks up at the ferris wheel, then runs off camera]
DANIEL: [in voice over] No one could've saved us!
[cut to another "flashback" of Daniel sitting in the backseat of a car, with a nauseous look on his face]
STEVE: [in voice over] You get scared when Mom drives too fast in the car!
DANIEL: [in voice over] Well, there's a speed limit for a reason!
[cut to another "flashback" of Daniel standing on a trampoline (remaining completely still)]
STEVE: [in voice over] You won't even jump on a trampoline!
DANIEL: [in voice over] Do you know how many kids get hurt on those things every year?
[cut back to the brothers in the playground, sitting on a bench]
STEVE: What are you afraid of, Daniel?
DANIEL: I-I dunno, I guess I just don't like all that moving ... Why do things have to move so quickly? What's wrong with being still? I like staying in one place! Like, this is fun! We could have tons of fun just sitting here, don't you think?
STEVE: Look Daniel, we are moving, okay?
DANIEL: No we're not.
STEVE: Yes we are. You and I, right now, are moving. Very fast, too.
DANIEL: You're crazy! I know the Earth moves, but it's very very very slow! Like a snail!
STEVE: No, we're moving at, like, a thousand miles an hour right now ...
DANIEL: I'm not falling for this!
STEVE: The Earth rotates, right?
DANIEL: Yeah, but it's not flat! Last year, you told me it was flat!
STEVE: That was a joke, okay Daniel?
DANIEL: You told me that, if I left the backyard, I'd fall off the Earth and be sucked into a bottomless void of terror!
[the older brother tries to suppress a laugh, then continues]
STEVE: Look, I'm serious this time, okay? Earth is whipping us around like crazy ... I-I saw it on TV.
DANIEL: You can't trust television ... Here, look.
[he gets up, then jumps up in the air]
DANIEL: See, I just proved you wrong!
STEVE: What're you talking about?
DANIEL: If the Earth's really moving so fast, how come when I jump, I land in the same place?
[Steve looks at him and says nothing]
DANIEL: Wouldn't the days be much shorter? I mean, the sun would just go up, and then come right back down! The days would be ten seconds long, and we'd be old men already!
STEVE: Look, I'm gonna go skate with the normal kids ... You stay still, don't move, I don't care! Okay?
[he takes his skateboard and leaves, then cut to Daniel walking up to a young woman sitting under a tree and reading a book]
DANIEL: Ma'am? Is this tree moving?
TREE READER: [pause] I hope not!
[cut to Daniel slowly walking down the street (keeping his hands out to maintain his "balance") when a male police officer on a segway rolls by]
DANIEL: Excuse me, officer!
POLICE OFFICER: Yes, sir?
DANIEL: Do you see that truck over there?
[he points at a truck parked on the sidewalk]
POLICE OFFICER: Yeah?
DANIEL: How fast would you say it's moving? My brother says it's moving at over a thousand miles an hour!
[the police officer simply turns and drives away, then cut to Daniel walking up to a woman drinking coffee at an outdoor cafe]
DANIEL: Excuse me, Miss ... How fast would you say the Earth is turning?
CAFE LADY: [pause] Am I on TV?
DANIEL: No, I'm just curious.
CAFE LADY: Ummm, slowly. Very slow ... Uh, wait, not at all!
DANIEL: [pause] Thank you.
[he gives her a confused look, then walks away]
CAFE LADY: Did I get it right?
[cut to Daniel walking up to a man fixing the wheel on his bicycle]
DANIEL: Sir? How fast would you say the Earth is moving?
MAN WITH BICYCLE: About twelve hundred miles an hour.
DANIEL: That can't be right!
MAN WITH BICYCLE: Oh, it's a proven fact ... Isn't it wonderful? We're all zipping around the universe together!
DANIEL: Uh, I can prove you wrong right now!
[he again jumps up in the air]
DANIEL: See? If the Earth was really moving that fast, wouldn't I have landed in that fountain over there or something?
[he points off camera, but the man just shakes his head]
MAN WITH BICYCLE: Oh no, that's easy ... Uh, you're moving at the exact same speed as the Earth.
DANIEL: [pause] What?!
MAN WITH BICYCLE: When you're born, you're already turning with the Earth ... so you were born moving twelve hundred miles an hour!
[he spins the wheel around and smiles]
MAN WITH BICYCLE: Isn't that cool?
[Daniel puts a hand over his stomach and staggers off]
DANIEL: Oh, I think I'm gonna be sick ...
[cut to Daniel running into the Lexington Public Library, then cut to him sitting at a table leafing through several physics/science books (he actually tosses one aside as it slides off the table and hits the floor) as a young female librarian (black hair in a ponytail, glasses, blue blouse, black pants) watches him from the front desk]
[cut to a closeup of Daniel, as he puts down another book in frustration and stares out the window]
DANIEL: Twelve hundred miles an hour? Everything moves so fast ... all the time? There's no hope.
[the librarian walks up to him with a concerned look on her face]
LIBRARIAN: Can I help you, sir?
DANIEL: We're doomed! Someday the whole Earth will ... stop spinning, or maybe even start spinning faster! And then we'll just all fly all over the place! It'll be mayhem!
[she gives him a confused look]
LIBRARIAN: Did you read this somewhere?
DANIEL: It's common knowledge ...
[he folds his arms, and she smiles at him]
LIBRARIAN: Lemmee show you something.
[she turns and starts walking away, as he gets up and (slowly) follows her]
DANIEL: Whoa, slow down! I can't walk very straight ... We're spinning right now, me and you!
LIBRARIAN: I see.
DANIEL: You were born spinning, did you know that?
LIBRARIAN: I read that somewhere ...
[she stops at a glass railing, then turns to him]
LIBRARIAN: Look down.
DANIEL: [pause] I can't stand heights.
LIBRARIAN: You should see this.
[they both look down towards the library rotunda, where a large Foucault pendulum is swinging back and forth]
DANIEL: That thing, it's swinging.
LIBRARIAN: It's a pendulum.
DANIEL: It's gonna break through the glass!
LIBRARIAN: No, it swings in constant motion. You can rely on it.
[he points at the cable attached to the ceiling]
DANIEL: That rope will snap eventually, and it'll land right on Kentucky!
LIBRARIAN: You're worried that the Earth is spinning out of control?
DANIEL: Isn't everyone?
LIBRARIAN: Watch the pendulum ...
[he looks down and watches the pendulum swing back and forth]
LIBRARIAN: Did you see that?
LIBRARIAN: We moved.
DANIEL: We did?
LIBRARIAN: Everything moved. The entire Earth shifted.
[he points at a bookshelf behind them]
DANIEL: Those books moved?
LIBRARIAN: They did.
[he points at the elevator]
DANIEL: The elevators?
[he points at an elderly man sitting in a chair and reading a book]
DANIEL: That man moved?
LIBRARIAN: Even him. Does that scare you?
DANIEL: Not really.
LIBRARIAN: You can't exist on this Earth without turning.
DANIEL: That didn't seem like twelve hundred miles an hour ...
LIBRARIAN: If you stood here for twenty four hours straight, you could watch the entire floor move in a perfect circle ... It would be a beautiful show. It happens every day, and it will continue to happen long after you and I are memories.
[she walks off, as Daniel continues to stare at the pendulum (and the camera rotates to give the illusion of movement)]
[cut to Daniel browsing through the stacks, when he stops and pulls a copy of "The Life and Science of Leon Foucault" from the shelf]
DANIEL: [in voice over] Leon Foucault?
[cut to a closeup of an illustration from inside the book, then Daniel lowers the book so that the camera catches a group of students standing around the pendulum in the rotunda]
DANIEL: [in voice over] "In Eighteen Fifty One, a French scientist named Leon Foucault demonstrated his new pendulum in Paris, France."
[cut to Daniel walking up to the pendulum and watching it at eye level]
DANIEL: [in voice over] "The crowd that day was astonished to realize Foucault's pendulum proved that the Earth was spinning beneath their feet, and they were going along for the ride."
[cut to another shot of Daniel watching the pendulum]
DANIEL: [in voice over] "A pendulum hangs from a fixed point, and when pulled back and released, it's free to swing down by force of gravity, and then out and up because of its inertia."
[cut to Daniel standing on the top floor above the pendulum again]
DANIEL: [in voice over] "A pendulum can be used to provide accurate time-keeping, like in a grandfather clock. A wire surrounded by an iron collar, with an electromagnet, keeps the pendulum moving."
[cut to a closeup of Daniel's face, as he looks up and sees where the cable is attached to the ceiling]
DANIEL: [in voice over] "The magnet attracts the wire, and is turned on and off automatically."
[cut to another closeup of Daniel, as he stands with his back to the camera]
DANIEL: [in voice over] "Foucault's pendulum proves that the Earth does rotate ... No dizziness. No wobbles. We're all moving, together!"
[he raises his arms up into the air in triumph, then cut to Daniel happily jumping on the trampoline (as his brother enters the scene and watches in shock)]
[cut back to the pendulum, as a young girl and her mother are watching up above from behind the glass railing]
DAUGHTER: What's this?
MOTHER: It's ... some sort of clock.
[Daniel enters the scene and stands next to the mother]
DANIEL: Actually, it's a pendulum.
DANIEL: It's a device that proves the Earth rotates. People used to think that the sun rotated around us and the Earth was flat, but this pendulum proved them all wrong.
[he points up]
DANIEL: It's a clock, too.
[cut to a shot of the blinking Roman numerals on the ceiling, then cut to two men looking at the pendulum from behind the glass railing]
BUSINESSMAN #1: I don't get it.
BUSINESSMAN #2: You see, it's moving ... so that proves that we're moving!
BUSINESSMAN #1: But the pendulum is attached to the building ... so the pendulum moves with the building. Therefore, it doesn't make sense!
[Daniel enters the scene]
DANIEL: The pendulum's not moving with the building ... Everything else is. It's because of inertia and gravity. Inertia means that a body in motion will stay in motion, and gravity is the force that keeps us connected to the Earth.
[the first businessman turns to him with interest (while the other checks his watch)]
BUSINESSMAN #1: So, the pendulum's moving, not the floor.
DANIEL: No no, the pendulum swings in exactly the same spot all the time ...
[the other businessman walks off]
DANIEL: But the building and the floor moves around it.
BUSINESSMAN #1: Hmm.
[cut to another shot of the camera rotating (giving the appearance that the floor is moving around the pendulum in real time)]
DANIEL: [from off camera] So, if the pendulum seems to be rotating with the floor, and we know there's nothing making the pendulum rotate ...
[cut back to Daniel, as he is now talking to three women standing behind the glass railing]
DANIEL: Then it must be the floor rotating!
[they peer over the railing, then cut to Daniel speaking to another woman who is wiping the railing with a cloth]
DANIEL: And we know the floor's attached to the Earth, so that must mean the Earth's rotating.
WOMAN WIPING RAIL: [pause] Makes sense.
DANIEL: You can count on it.
[she leaves, then cut to Daniel back at the playground, as he lies down on his back on the spinning turnwheel and looks up at the sky]
[cut back to the library, as Daniel is standing with a group of students standing around the pendulum]
PENDULUM GIRL: How fast did you say we were spinning?
DANIEL: Twelve hundred miles an hour.
PENDULUM GIRL: So we're all moving really fast right now?
DANIEL: But, we're all moving together ... Everything on Earth spins at exactly the same speed, so nothing will fly off.
PENDULUM BOY: Sweet!
PENDULUM GIRL: You're pretty smart.
DANIEL: Nah ... I just hang out at the library.
[cut to Daniel sitting in the backseat of his mother's car, while his brother sits in the front seat (reading a "World of Warcraft" players' manual)]
DANIEL: Hey mom, let's see how fast this thing can go!
[the car speeds up and Daniel puts his arms up in excitement (as Steve looks at him and just shrugs), then cut back to the library as the two brothers look over the glass railing at the pendulum]
DANIEL: You wanna see the Earth rotate?
[cut to an overhead view of the pendulum, then back to the two brothers]
STEVE: What keeps the pendulum going?
DANIEL: Inertia and gravity.
STEVE: Hmm, inertia and gravity ...
DANIEL: It's complicated, but ... let's just say you were right. The Earth does move pretty fast.
STEVE: So that means we're moving pretty fast. That doesn't scare you?
DANIEL: I like motion. Without it, there wouldn't be any sunsets or storm clouds or ocean waves or life at all. We need to spin.
[cut to another overhead view of the pendulum, then back to the brothers as Steve shakes his head]
STEVE: This is making me dizzy. Come on, Daniel.
[he walks towards the elevators, but Daniel keeps staring at the pendulum (as the camera again rotates)]
STEVE: [from off camera] Daniel!
[cut back to the brothers, as Steve is waiting for Daniel to follow him]
STEVE: Look, you're ready to ride the ferris wheel now, right?
DANIEL: [pause] One step at a time!
[he turns and heads for the elevator, then cut back to the playground, as Daniel sees another girl on the swingset and joins her]
DANIEL: Y'know, this is kinda like a pendulum ...
GRAVITY GIRL: Yeah ... Thank goodness for gravity!
[they continue swinging side by side, as the scene fades to black]
(in order of appearance)
Monkey Bar Kid
Hobby Horse Kid
Man with Bicycle
Bryn Waterbury Eichhorn
Businessman No. 1
Businessman No. 2
Glass Rail Lady No. 1
Glass Rail Lady No. 2
Glass Rail Lady No. 3
Woman Wiping Rail
Pendulum Kid No. 1
Pendulum Kid No. 2
Pendulum Kid No. 3
Alberta Labrillazo and the staff of SCAPA Bluegrass
The SCAPA parents
James and Beth Pennington
Lorie Bowen, Bob Blanchett & Patrick Goff, Fayette County Public Schools
Jeremy Kissling and the staff of the Lexington Children's Theatre
LFUCG Parks and Recreation Department
Lexington Police Department
California Academy of Science
The University of New South Wales
The staff of the Lexington Public Library
A production of the
Lexington Public Library
Cable Channel 20
The boy featured in this video has concerns about spinning through space on Earth until he is introduced to a Foucault pendulum. He learns that French scientist Jean Bernard Leon Foucault used his knowledge of pendulums to demonstrate Earth's rotation and how that movement is a steady, measurable motion rather than a dangerous one.
The Foucault pendulum was the first demonstration of the Earth's rotation that did not rely on astronomical observation.
This was first demonstrated in 1851 by French physicist Jean Bernard Leon Foucault. Foucault noticed that if a pendulum is turned, it tries to keep swinging in its original direction. From this, he theorized that a pendulum could be used to observe the rotation of the Earth. Foucault went on to demonstrate the Earth's rotation publicly at the Paris Observatory and then at the Pantheon in Paris.
But how does a pendulum demonstrate the Earth's rotation?
As you watch the pendulum for just a short time, it will appear to be moving clockwise across the mosaic map on the floor.
But, since there is no outside force making the pendulum rotate as it swings, and no other outside force interrupting the swing, it must be the floor itself that is rotating, while the path of the pendulum's swing remains constant.
The apparent rotation of a Foucault pendulum is affected by two kinds of motion: twisting and travelling. Twisting is circular motion directly on an axis. Travelling is circular motion around an axis.
To help understand this, consider two Foucault pendulums, one placed directly on the north pole and the other placed directly on the equator. At the north pole, the pendulum's swing rotates in a complete circle every 24 hours – it twists but does not travel any distance. At the equator, the pendulum travels a wide path around the Earth's axis but does not even begin to make a circle – it travels but it does not twist at all.
A Foucault pendulum placed in between the pole and the equator is affected by both twisting and travelling. The closer it is to the pole, the faster it circles. The library's pendulum, located at 38 degrees, six minutes, does a complete circle about every 38 hours. Because air resistance would stop the pendulum's motion, magnets at the top gently pull the pendulum to keep it moving, and the pendulum is suspended in a way that allows it to swing freely, regardless of the building's movement.
For a more in-depth explanation of how a pendulum demonstrates the rotation of the earth, read About Foucault Pendulums at the California Academy of Sciences.
The apparent rotation of the library pendulum is tracked by sensors in the mosaic on the floor, which light up as the plumb bob passes over them. The slow progress of the lights and the pendulum create a truly mesmerizing show.