Up the hill and down the drop, hop aboard this episode of Brains On!

How do roller coaster designers go from dream to reality? Brothers Ezra and Ottar interview world-renowned roller coaster designer Alan Schilke to find out how he does it.

Also — why do some people feel sick or dizzy after riding them? How do coasters make you feel like you’re floating? And don’t forget the mystery sound – it’s a real stumper.

Even if you’re not tall enough for every ride, you’re definitely tall enough for this episode.

Ottar and Ezra’s designs

Ottar and Ezra dream up their own roller coaster designs. Do you have any roller coaster ideas? Send them to us here.

Grand Canyon design by Ottar.
Grand Canyon design by Ottar.
Molly Bloom
13: The Doomsday Ride by Ezra.
13: The Doomsday Ride by Ezra.
Molly Bloom

Sound effects in this episode provided by freeSFX.

This episode originally aired Dec. 17, 2014. Listen here:

Roller coasters: From dream to extreme
by MPR

Audio Transcript

Download transcript (PDF)

EZRA: You're listening to Brains On.

OTTER: Where we're serious about being curious.

SUBJECT 1: Brains On a supported in part by a grant from the National Science Foundation.


MOLLY BLOOM: Roller coasters take you to amazing heights.

EZRA: And mind boggling plunges.

OTTER: They take you upside down.

EZRA: And around steep curves.

MOLLY BLOOM: Roller coaster designers have been thinking of new ways to thrill riders for over 100 years. And they're still coming up with more.

OTTER: But how do they do it?

EZRA: How do they get from dream to reality?

OTTER: We're going to find out right now.

MOLLY BLOOM: Even if you're not tall enough for every ride, you're definitely tall enough for this episode of Brains On.

EZRA: Keep listening.


MOLLY BLOOM: You're listening to Brains On from American Public Media. I'm your host Molly Bloom. And I have two co-hosts here with me today, brothers Ezra and Otter from the Twin Cities. Hello.

OTTER: Hello.


MOLLY BLOOM: Ezra and Otter inspired this episode with their fierce roller coaster passion. Ezra, you're 11, and Otter is 8. So when did you first start getting interested in roller coasters.

OTTER: Well, the day of my sixth birthday party my dad took me to the state fair and I went on rides and I started thinking maybe someday I should build an amusement park that has even better rides.

MOLLY BLOOM: So you guys dream up your own designs. Can you tell us about a couple of your designs that you've done recently?

OTTER: One of them was a coaster that would go up a lift, then go down drop that actually kind of spirals before the drop and then dive down quickly.

MOLLY BLOOM: So it's sort of so right at the top of the hill, there's a spiral and then a steep drop.


MOLLY BLOOM: What would it be called? Do you have a name?

OTTER: Yeah.

MOLLY BLOOM: What is it?

OTTER: Velociraptor.

MOLLY BLOOM: Now Ezra and Otter have taught themselves a lot about coasters. But they still had questions. And they wanted to talk to one roller coaster designer in particular.

OTTER: Alan Schilke.

EZRA: Alan Schilke is a legendary roller coaster designer responsible for many recent innovations, including the fourth dimension coaster.

MOLLY BLOOM: What is a fourth dimension roller coaster?

EZRA: A fourth dimension roller coaster is a roller coaster where the seats roll upside down. And so you can start in the back of the train facing forwards and end in the front of the train facing backwards.

MOLLY BLOOM: OK. Explain how that works.

EZRA: The seats use a hydraulic mechanism to roll upside down.

MOLLY BLOOM: OK. So they're kind of like somersaulting.

EZRA: Yes.

MOLLY BLOOM: So that's kind of the motion.

EZRA: Independent of the track. So how it starts out is you're in what seems like the back, facing normally so you can see everyone in front of you. But you go up the hill forwards. And then if the train rolls over and then the seats roll over, you are facing forward and everyone else is behind you.

MOLLY BLOOM: Whoa. That sounds terrifying to me. So you guys got a chance to interview Alan who invented the fourth dimension coaster.

OTTER: We asked him where he gets his inspiration for the roller coaster he designs.

ALAN SCHILKE: I get my inspiration from many places, everything from doing sports activities myself to watching X Games on TV. Basically everything I try to do is take something that I see exciting in real life that I wish that I could do and kind of try to put that into a coaster, so that other people can do it as well.

I like to invent new things. For example, we just recently worked on a new system to pull the coaster to the top of the hill. So instead of it being very slow like a normal chain, it uses a cable and pulls the coaster to the hill very fast to the top. I spent a couple of weeks just thinking about nothing else because it was new. It's almost like you can't stop me from designing it and to do it. So those are always the funnest. The first time is really, really what being a designer is all about.


MOLLY BLOOM: We're going to hear more from Alan Schilke in just a little bit. Right now we have some important business to take care of. It's time for the mystery sound.

SUBJECT 2: Mystery sound.

MOLLY BLOOM: Here it is.

Any guesses?

OTTER: It sounds like a space shot going up a tower, which is a kind of towel that launches you up to the top.

MOLLY BLOOM: Good guess. Do you have a guess, Ezra?

EZRA: It sounds like a roller coaster train being released from the station.

MOLLY BLOOM: Also a good guess. Now I just want you to know I worked really hard to find a sound that you might not know because you guys know so much about roller coasters. So I'll let you think about it a little bit more because it's a hard one. We'll reveal the answer later in the show.


How would you describe how a roller coaster makes you feel?

OTTER: Well, they make me feel excited before I'm on and after. Like good that I just went down a new coaster or if I've already been on it, just it's always good.

EZRA: Well, if I've never been on that particular roller coaster before, if I see people screaming on it, or they come out of line, and they don't seem to like it, I'll get really, really nervous. But then I'll usually like it.

And then as soon-- and while I'm on it, I'm going to be screaming my head off with my hands up most of the time. And then when I get off, I just feel like I want to get on that again right now.

MOLLY BLOOM: It's a thin line between a roller coaster making you feel exhilarated and making you feel sick.

EZRA: So we asked Alan how he makes sure his designs don't make people sick.

ALAN SCHILKE: If you go too slow it's very safe for the riders, and you're not worried about injuring anybody. But it also wouldn't be fun enough. It wouldn't take people's breath away. If you do it too extreme, you can actually even hurt somebody. So finding that point that you get everybody excited, but nobody comes away hurt or nobody comes away saying, hey, that ride kind of beat me up, that is really the key. And that's kind of what all of the roller coaster design that I do is based on, hitting that point as close as you can because you may know where you want to go, but how you get there is very important.

And so like if you're in a positive G in a pullout at the bottom of a hill, and you get all those G-forces on you. And then you're going to come up into the first floating element. How fast do you go from, say positive 3 and 1/2 Gs to zero Gs? That is the balance. And that's really a roller coaster designer's job.

MOLLY BLOOM: So let's stop for a second and explain what a G-Force is.

SUBJECT 3: G-force.

MOLLY BLOOM: Here G stands for gravity. Gravity is a force that pulls you down toward Earth. If you throw a ball up, it comes back down. That's gravity. Now gravity is the key to how roller coasters work. The reason a roller coaster is pulled up to the top of a high hill at the beginning is all about gravity. The roller coaster is slowly building up potential energy as that chain pulls you up higher and higher. Then it's the top of the hill, You hand all that energy over to gravity and say, hey, go nuts. And away you go.

So when you're on a roller coaster, you're feeling too forces on you, gravity, which you always feel, and the acceleration of the car. Have you heard the term inertia before?

EZRA: I'm learning about it in science class right now.

OTTER: I don't know what is.

MOLLY BLOOM: OK. So we'll tell you. That's one of the basic laws of motion. It says that objects want to keep doing what they're doing. If it's sitting still, it wants to keep sitting. If it's moving forward, it wants to keep moving forward until some external force stops it.

So inertia makes you feel acceleration in a funny way. It's the roller coaster seat that's pushing your body forward, but you feel the force form in front of you. Since that feels the same as gravity's force on you all the time, it's called a G-force.

SUBJECT 3: G-force.

MOLLY BLOOM: A G-force makes you feel heavier or lighter. 1G is equal to the force of acceleration caused by gravity, which determines how fast objects fall when dropped and how heavy you feel on Earth. 1G is hard to notice because we're used to it. It's how we feel all the time. 2Gs makes you feel twice as heavy. Half a G makes you feel half as heavy. Fighter pilots experience 6Gs. And on the moon, it's one sixth of a G.

So even though you're strapped and your body is not a part of the roller coaster car and because of inertia, your body wants to keep going the direction it's already going in. The train changes directions before you do. When you're at the top of a drop, the track pulls the car down away from you much faster than you would fall if the track just suddenly disappeared.

Here you feel negative Gs that make you feel like you're going to fly out of your seat. The car is actually falling faster than gravity. So you'd fly out if you didn't have a seat belt on.

SUBJECT 4: Brains on.


MOLLY BLOOM: Roller coasters are fun most of the time. But sometimes they make us feel sick. We get dizzy, queasy. We feel like we might throw up. So why does this happen? Hold on to your barf bags. We've got an explanation.

SUBJECT 4: It's called motion sickness and it happens when your sense of where you are in the world gets out of whack. Now normally you have three different systems that tell you where you are in space. You've got your body.

BODY: Yeah, feet on the ground, feeling fine.

SUBJECT 4: Then there are your eyes.

EYES: OK. I see the ground below, the sky above. Everything's normal. Just the way I like it.

SUBJECT 4: And then there's the inner ear.

INNER EAR: Why, hello.

SUBJECT 4: Your inner ear has a special organ that helps it sense tilt, spin, and changes in speed.

INNER EAR: It's called the vestibular complex. And just what is a vestibular complex you ask. Well, a vestibular complex is a series of tiny tubes lined with microscopic hairs and filled with ear gel.

BODY: Wait, bro, did you say ear gel?

EYES: That sounds kind of gross.

INNER EAR: Actually, it's really interesting. When you move the ear gel sloshes around in these tubes. Those tiny hairs the tubes sense that sloshing and send signals to your brain telling it about the movement.

BODY: Whatever you say, ears.

EYES: As long as I don't have to see the ear gel, I guess I'm fine with that.

SUBJECT 4: Now normally these three systems, body, eyes, and ears get along just fine and your stomach feels fine.

STOMACH: Yep, I'm cool.

SUBJECT 4: But sometimes they disagree, like if you're below deck on a boat.

EYES: To me, everything looks stable. I mean, sure the walls down here could use a paint. Those decorations are hideous. But I don't really see things moving much. We must be standing still.

BODY: You're crazy the ground's like super shaky. Things keep rocking. Whoa. I almost fell down there.

INNER EAR: Yeah, my ear gel sloshing around a lot. Taking that into account, we must be moving.

BODY: Dude, could you stop talking about ear gel? You're going to make me sick.

EYES: Can't you see you're both wrong? Clearly, the ground is below us and the ceiling is above. The walls are staying still. We are not moving.

INNER EAR: We are definitely moving. Can't you not feel that gel sloshing around?

BODY: Don't make me come over there and--


EYES: But you're totally wrong.

SUBJECT 4: When your senses don't agree, you feel disoriented and start to feel sick to your stomach.

STOMACH: I don't feel so good.

SUBJECT 4: That's why some people get seasick or carsick. Now imagine you're climbing up a steep hill on a roller coaster.

EYES: Wow. I can see everything from up here. This is amazing.

BODY: Yo, Eyes, could you check see that I'm strapped in here all right?

EYES: Yeah, you're good, Body.

INNER EAR: We are so high that I think I might need to pop myself. Ah, that's better. Wait, are we slowing down?

EYES: Don't look now, but there's a huge drop ahead. Ah, where's the ground? Where's the sky?

BODY: I feel like I weigh a million pounds.

INNER EAR: Oh, the sloshing.

EYES: No, wait, seriously, which way is up? I can't tell. Is that it?

BODY: No, I think it's that way.

INNER EAR: I don't care where it is. Just make it stop.


SUBJECT 4: Roller coasters can really do a number on your senses. The more confused they get, the sicker you end up feeling. Some people senses are better than others at handling this kind of movement. That's why they don't get sick easily. But if you do end up queasy on a roller coaster, just remember, when you get off to take it easy on your poor. Senses maybe go find a quiet still place for them to catch their breath.

BODY: OK. That was crazy. I'm sitting us down.

EYES: Good idea. I feel like I'm still seeing loops.

INNER EAR: Do me a favor though, sit down slowly. And let's never fight again.


MOLLY BLOOM: So that's the answer to why some of us get sick on roller coasters.

EZRA: Do you have any questions you want Brains On to answer?

OTTER: Send them to us.

MOLLY BLOOM: You can do that by heading to brainson.org/contact. That's how this fascinating question was sent to us.

MOSES: My name is Moses from Indianapolis, Indiana. My question is why did boomerangs come back.

We'll answer that during our Moment Of Um at the end of the show. And we'll list the most recent group of listeners to be added to the Brain's Honor Roll. Stay tuned. And before we get back on this ride, it's time to check in with our pal, Joy Dolo. Hi, Joy.

JOY DOLO: Hi, Molly.

MOLLY BLOOM: Joy is the host of our new show called Forever Ago.

JOY DOLO: Yeah. Every episode we dive deep into the history of one cool thing. This week coming out on Thursday is an episode all about sandwiches.

MOLLY BLOOM: Sounds delicious.

JOY DOLO: Well, here's a taste. Once people had coined a word for this super convenient super delicious food the sandwich, it kept spreading. Pun intended, I guess. And you can see that in old cookbooks. So this recipe is from 1837. So this is still more than 40 years before people had electricity in their houses. And it comes from a woman named Eliza Leslie.

ELIZA LESILE: Cut some thin slices of bread very neatly, having slightly buttered them. And if you choose, spread on a very little mustard. Have ready some thin slices of cold boiled ham and lay one between two slices of bread.

JOY DOLO: Did you catch that? That is a recipe for a ham sandwich.

Well, I guess when you started them back then you need to write it down because you need to know the order. Otherwise, you'd have ham on the outside and bread on the inside.



SUBJECT 5: That would be so weird.

MOLLY BLOOM: If you want to hear the rest of that episode, find Forever Ago and subscribe wherever you get your podcasts. Now Joy, before you go, I want to ask you a question. We're working on a brains on episode right now all about how amazing Earth is. And here's the question we want our listeners to help answer. If you could write a very short and sweet letter to Earth, what would you say? So Joy, what would you say to Earth?

JOY DOLO: Well, I would start with, dear, Earth.

MOLLY BLOOM: That's good start.

JOY DOLO: That's how I start most of my letters, so don't take it personally, Earth. Dear, Earth, you have so many peaks and so many valleys, just like me. I mean, it would go on more sweeter and more poetic as we went on. But it would be something about how there's a lot of highs and a lot of lows. And like there's all these different kinds of but also like this violence that it can cause. And it would be very poetic and natural sounding and beautiful.

MOLLY BLOOM: I love it. I think the Earth would really appreciate that.

JOY DOLO: I think so, and I think I'm going to give Shakespeare a run for his money. Watch out.

MOLLY BLOOM: I think so. Well, listeners, you can send us your answer. What would you say in your dear planet Earth letter? Send it to us at brainson.org/contact.

JOY DOLO: Can't wait to hear those answers.

MOLLY BLOOM: Joy, thanks so much for stopping by.

JOY DOLO: Of course, thanks, Molly. Bye.



You're listening to Brains On from American Public Media. I'm Molly.

OTTER: And I'm Otter.

EZRA: And I'm Ezra.

MOLLY BLOOM: And today's episode is taking us on a wild ride.

EZRA: We're finding out how roller coasters go from dream to reality.

MOLLY BLOOM: Part of that reality can get a little noisy, which means it's time to return to the mystery sound. Let's hear it one more time.

Ready for the answer?

EZRA: Yeah.

MOLLY BLOOM: OK. Here it is.

PETE WIDSTRAND: That was the sound of the break test on the Fairly Odd Coaster at Nickelodeon Universe.

MOLLY BLOOM: Nickelodeon Universe is an amusement park at the Mall of America in Minnesota. And it's actually an indoor amusement park. Pete Widstrand is a mechanic who's on the maintenance crew there. They're in charge of making sure the rides run smoothly.

PETE WIDSTRAND: The first really loud noises is the air being released and then the brakes closed because there's no air pressure holding them open. And then the second loud noise is the car actually hitting the brake. Generally, you go to a visual inspection, make sure everything is where it should be. We have PMs. It's preventive maintenance is what a PM work order is. So it's greasing moving parts. It's changing the oil, changing filters. That kind of thing.

After you've determined that everything is safe and in working order, then we do the physical test of running the equipment. You can listen. A lot of it is your ears listening and visually looking for visual clues. After they're satisfied that everything's OK, then they'll do a brake test and then make sure that the cars stop where they should. They don't go through too far.

If a car did make it through, then you would be not opening the ride on time. And you'll be doing more work and fixing whatever went wrong.

MOLLY BLOOM: As we've heard, a lot goes into making sure roller coasters are safe for riders. Remember Alan Schilke from earlier in the episode? It's up to designers like him to think about even the smallest details.

ALAN SCHILKE: A wooden coaster for example, let's say if I was going to design the path that the riders are going to take, every support that goes along the way, every bent of wood contains many, many structural members. A lot of wood pieces, a lot of bolts to connect them together. Somebody has to calculate that and say that it's strong enough, make sure it's safe. That it'll stand up, not just to the coaster forces but also to wind and earthquake forces. That might take three times as long as it does to design the fun.

EZRA: You recently built a roller coaster that set the record for steepest and fastest wooden coaster. How did you make sure it didn't go too steep and too fast?

ALAN SCHILKE: Well, I have programs that I've written. I've been using them for the last 25 years from previous rides. I know that ride-- like if I'm shooting for, let's say, a negative 1G to make sure that there's not too much force on the rider in the back seat, I'm basically predicting in a way what the ride is. But I've been doing it so long that my predictions are extremely close.

So I look at every seat on a coaster to know what the G-forces are on the person in every seat, so I know that when I'm coming over the top of the hill I know exactly if I'm trying to hit negative 1G, that the back seat rider will hit negative 1G all the way down the hill. And I can map out the curve of the drop to match that perfectly. So it is a prediction. But it's a very scientific prediction. There's really not much left up to chance.

OTTER: What's something that you wish coasters can do that they can't do yet?

ALAN SCHILKE: I'd really love to be able to make a coaster that actually leaves the track. So that's kind of what we're doing when we design these air time hills. Is we're simulating what it might be like to hit a ramp and have the cost of release. But of course, the coaster car stays connected. And this isn't something that I think ever should be done in the future. But that sure would be something if the car could connect, fly across a big gap like they do on a car jump or a motorcycle jump and then reconnect. That sure would be fabulous.

MOLLY BLOOM: What do you guys think is the future of roller coasters?

EZRA: I think wood coasters are going to become a lot more like steel coasters are. Now they might make a fourth dimension wood coaster or a launched wood coaster where it uses a system that isn't gravity to propel it.

OTTER: Someone should probably make a coaster that kind of simulates something. Like let's say it goes down a big drop, but you're in a tunnel but then see something else, and it seems like you going back up, but you really feel going down.

MOLLY BLOOM: Ezra and Otter have designed some roller coasters. We're going to post a couple of their drawings on our website. And we'd love to see yours too. If you have any ideas or designs for roller coasters, send them to us at brainson.org/contact.


EZRA: A lot goes into designing roller coasters.

OTTER: You need to understand gravity.


EZRA: Engineering.

OTTER: And the way they affect your bodies.

MOLLY BLOOM: While still trying to come up with new ideas to thrill riders.

OTTER: That's it for this episode of Brains On.

EZRA: This episode was produced by--


MOLLY BLOOM: Many thanks to


Also special thanks to our voice actors.


OTTER: To hear more episodes, head to a website brainson.org. Or subscribe in your favorite podcast app.

MOLLY BLOOM: Now before we go, it's time for Our Moment of Um.

SUBJECT 6: Um, um.

SUBJECT 7: Um, um.


MOSES: Why do boomerangs come back?

LOGAN BROADBENT: What actually makes the boomerang return is something called aerodynamics. And it works all the scientific principles like gyroscopic precession, differential lift, centrifugal force, moment of inertia, and angled momentum with torque. Sorry, I tried to say that in one breath. My name is Logan Broadbent.

And I'm actually a world boomerang champion. I'm a member of the US National boomerang team. We're the current defending world champions. And I finished second in the world as an individual.

All boomerangs are thrown straight up and down, nice and vertical. And the reason for that is because each wing of a boomerang, when you look at a boomerang, some boomerangs have two wings, some boomerangs have three wings. And each of those wings is almost like an airplane wing. So each wing generates lift.

But when you're throwing a boomerang, the direction of lift is to the side rather than up in the air. So instead of the boomerang going straight up and coming down and crashing, a boomerang is thrown vertically, so it's the direction to lift it to decide which causes it to curve and come all the way back. And using Bernoulli's principles of lift, which talks about how fast moving molecules over the top of the wings creates low pressure and slow moving molecules create high pressure from underneath, that's what allows the multi-ton aircraft to fly in the air. It's what allows airplanes to work. And it's the same thing that allows boomerang to come back.

The original returning boomerang actually came from Australia. The Aboriginal people, the native people of Australia were the ones who invented the returning boomerang. They were actually developed from something called a throw stick, a hunting stick. In Australia, they called it a Kylie. And those were actually used as multipurpose tools.

So those were used for hunting. They were also used as musical instruments for clacking together. They were used to dig up water roots in the arid desert. It was the Aborigines version of a Swiss army knife.

MOLLY BLOOM: I'm feeling very aerodynamic and ready to fly through this list of names. It's the Brain's Honor Roll. These are the brilliant listeners who dedicate their brainpower to coming up with questions, drawings, and mystery sounds for us.




We'll be back soon with more answers to your questions.

EZRA: Thanks for listening.

MOLLY BLOOM: Can you give us a demonstration of what it sounds like when you ride a roller coaster?


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