I Failed at The Rotor
August 31, 2016 12:34 PM   Subscribe

Remember the carnival/shitty amusement park ride called The Rotor? For anyone who doesn't, people would stand against the wall of this cylinder that would start spinning. After a little while, the floor would drop and everyone everyone would stick in place to the wall...

...but not me. As the floor dropped, I'd go with it. It's not like I was lubed up (my parents didn't believe in sunscreen in the '70's), but I never stayed in place like everyone else. I've been curious about why for almost 40 years. What gives?
posted by Maisie to Grab Bag (20 answers total) 4 users marked this as a favorite
 
Were you very slim?
posted by kate blank at 12:38 PM on August 31, 2016 [3 favorites]


Were you very not slim?
posted by the webmistress at 12:48 PM on August 31, 2016 [3 favorites]


Response by poster: Were you very slim?
posted by kate blank at 3:38 PM on August 31

Were you very not slim?
posted by the webmistress at 3:48 PM on August 31


No, like Goldilocks at the table with the porridge, I was neither very slim nor very not slim. I was around 5 feet tall and about a hundred pounds. (Boy, those were the days.)
posted by Maisie at 12:48 PM on August 31, 2016 [3 favorites]


I dunno, I just did that ride a few days ago wth a skinny seven year old (it was called "Starship Exodus," and when I was a kid it was "The Gravitron" but it's clearly the same machine with different signage) and it worked fine. Heck, the plush puppy he brought in with him stuck to the wall just fine too. That thing really pins you to the wall, it feels like a lot more than 1G. So basically I'm not sure why you experienced what you did, but I bet you weren't too light.
posted by Anticipation Of A New Lover's Arrival, The at 12:51 PM on August 31, 2016 [2 favorites]


Did this happen repeatedly, on different rides? If it was a one-time occurrence, maybe the machine wasn't running at its proper speed.
posted by Faint of Butt at 12:51 PM on August 31, 2016 [5 favorites]


Some online physics discussions (I googled Gravitron instead of Rotor) I found mention how weight isn't important, but the friction between your clothing and the wall is. Did you often wear slippery polyester clothing or something?
posted by janerica at 12:54 PM on August 31, 2016 [5 favorites]


Whenever this would happen it was because I wasn't positioned properly against the wall.
posted by Room 641-A at 12:54 PM on August 31, 2016 [1 favorite]


Though actually your version sounds a bit different than the one I was on, now that I think of it. Instead of the floor dropping away, the wall is covered with steeply-angled sliding boards and when it gets up to full speed (by which time you've been pinned firmly to wall for a little while already) they all slide up to the ceiling, with their occupants still attached.
posted by Anticipation Of A New Lover's Arrival, The at 12:55 PM on August 31, 2016 [1 favorite]


Response by poster: Did this happen repeatedly, on different rides? If it was a one-time occurrence, maybe the machine wasn't running at its proper speed.
posted by Faint of Butt at 3:51 PM on August 31


It happened every time and in different amusement parks.

Some online physics discussions (I googled Gravitron instead of Rotor) I found mention how weight isn't important, but the friction between your clothing and the wall is. Did you often wear slippery polyester clothing or something?
posted by janerica at 3:54 PM on August 31


No, my mom was (and still is) a lover of natural fibers. I wore cotton tee shirts and cotton shorts.
posted by Maisie at 12:55 PM on August 31, 2016


well i was just about to say what janerica said, so consider that endorsed by an (ex) physicist. and the "not positioned properly" that Room 641 mentions would reduce friction.
posted by andrewcooke at 12:56 PM on August 31, 2016 [3 favorites]


Consider yourself lucky. The one time I did that, I stuck, but I was also severely motion sick for about 18 hours.
posted by Mr.Know-it-some at 12:58 PM on August 31, 2016 [5 favorites]


Though actually your version sounds a bit different than the one I was on, now that I think of it. Instead of the floor dropping away, the wall is covered with steeply-angled sliding boards and when it gets up to full speed (by which time you've been pinned firmly to wall for a little while already) they all slide up to the ceiling, with their occupants still attached.

That was the one called the Gravitron. The Rotor was the one where the floor went down. These were two rides that worked on the same principle but were designed a little differently. Some places had both.
posted by If only I had a penguin... at 12:59 PM on August 31, 2016 [1 favorite]


Best answer: your version sounds a bit different than the one I was on, now that I think of it. Instead of the floor dropping away, the wall is covered with steeply-angled sliding boards

Luna Park in Melbourne has had both of these at various times. The floor-dropping version is The Rotor, and the angled boards version is The Gravitron.

As the floor dropped, I'd go with it.

Did you have very long hair?
posted by flabdablet at 1:00 PM on August 31, 2016 [14 favorites]


Another possible reason might be because you are short. In the versions of this ride that I have ridden, the wall that you lean against is angled backwards, so that your head is further from the center than your feet. Centrifugal force (for a constant angular velocity) is directly proportional to the radius of the rotation, so a shorter person with a lower center of gravity might well be less firmly stuck to the wall.
posted by firechicago at 1:00 PM on August 31, 2016 [4 favorites]


Response by poster: Consider yourself lucky. The one time I did that, I stuck, but I was also severely motion sick for about 18 hours.
posted by Mr.Know-it-some at 3:58 PM on August 31


Yuck; I'm sorry that happened to you. Like many misadventures in my youth, I came out of it humiliated, but otherwise unscathed.

[snip] Did you have very long hair?
posted by flabdablet at 4:00 PM on August 31


Yes! Could that have been the culprit?

Another possible reason might be because you are short. In the versions of this ride that I have ridden, the wall that you lean against is angled backwards, so that your head is further from the center than your feet. Centrifugal force (for a constant angular velocity) is directly proportional to the radius of the rotation, so a shorter person with a lower center of gravity might well be less firmly stuck to the wall.
posted by firechicago at 4:00 PM on August 31


Hey, no need for name calling! (Just kidding...I grew up to be a little under 5'2", so I know the pain of not being able to reach high cabinets. Fortunately I married a tall man.) This version of the ride didn't have sloping sides. It was straight up and down. That angled version sounds dangerous.
posted by Maisie at 1:11 PM on August 31, 2016


Best answer: [snip] Did you have very long hair?
posted by flabdablet at 4:00 PM on August 31

Yes! Could that have been the culprit?


Good call, flabdablet! If young!Maisie had a lot of long hair pinned between her back and the wall, that could have reduced the friction enough to make her slide.
posted by Faint of Butt at 1:24 PM on August 31, 2016 [8 favorites]


Good thinking, flabdablet!
posted by jamjam at 3:01 PM on August 31, 2016 [2 favorites]


Whenever I would wiggle and try to test my strength against the centrifugal force, that would separate parts of my body from the wall, reducing the friction and allowing me to inch down toward the floor.
posted by JimN2TAW at 3:05 PM on August 31, 2016 [1 favorite]


Best answer: Were you very slim? Were you very not slim?

Weight of the person does not matter. The friction force is caused by centripetal force normal to the wall. Centripetal force is proportional to weight. The gravitational force pulling you down is also proportional to weight. So the mass in the frictional force and mass in the gravitational force cancel. Heavy or light makes no difference in the physics.

"not positioned properly" that Room 641 mentions would reduce friction.

To a first approximation, the area of contact is independent of the amount of static frictional force. If you halve the area, the normal force doubles so they cancel each other out in the calculation of friction. So the area of contact makes no difference in the physics.

Did you often wear slippery polyester clothing or something?
Did you have very long hair?


Now we are getting somewhere. From above, your weight doesn't matter. Your size or area of contact doesn't matter. The diameter and velocity of the Rotor are identical for everyone. The one thing that you can vary is the coefficient of friction in the formula F = uN. Where u is the coefficient of friction and N is the normal force due to centripetal acceleration.

Different materials have different coefficients of friction -- sandpaper vs. silk for example. So they designed the machine's diameter and velocity to have sufficient friction with typical clothing materials. But if you have a shirt that rides up or long hair that is loosely attached to your body, they can act like ball bearings to reduce friction and you don't "stick" to the wall.
posted by JackFlash at 4:24 PM on August 31, 2016 [11 favorites]


The Rotor appears in a Charlie's Angels episode.
posted by rhizome at 10:00 PM on October 20, 2016


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