I'm struggling to see how it would be very interesting compared with, say, a rollercoaster or a drop tower, where there are external frames of reference, and full 1G (or more) acceleration / weightlessness.
I imagine the experience would be about as interesting as taking an elevator down a tall building. Maybe I am missing something, though?
You could make the first part of the experience free-fall (throw people with a magnet strapped on down a tube that is conductive only near the bottom).
I think the big problems are that you need a hefty magnet (which is inherently dangerous) and you can't really split up the magnets over the body (because that is INSANELY dangerous), so you experience that same thing that could be achieved via bungee cord/harness.
You would also need to limit (lateral) movement quite a bit, to get reliable braking...
A x-shaped magnet assembly strapped to the back could work, but you probably could not allow the tube being all that much bigger in diameter than that backpack...
edit: If you allow any fall configuration different from feet-first, the terminal velocity has to be pretty low to reliably not kill people, too. But you could make this work with a net, I think...
I'm inclined to agree that his likely is one of those situations where despite the novelty maybe provided by the new tech, old tech does this job better or at least sufficiently that you still end up using old tech.
> I think the experience of falling slowly down a tube would be very interesting.
So, like an elevator?
I agree that Lenz's law is pretty neat. In high school my electronics class got to visit a research MRI and bring in coils of wire and other objects to experience it first-hand.
Pretty sure it can be done with aluminum pretty well, so it probably wouldn't be that expensive compared to some rides.
You couldn't use multiple magnets on the person or they might smash together, and you'd have to be very careful guests stayed apart, and that they didn't have anything magnetic in their pockets to go flying towards the magnet and hurt them.
You could do it with air pressure, like indoor skydiving in a confined area, but it would probably be loud and somewhat unpleasant.
Since people aren't magnetic it would probably feel exactly the same as jumping with a harness on a cable instead of with magnets.
Unless you used the frog levitation thing but that's a different effect and would probably be really expensive
There is no way you could put the magnets on the rider. Variance in body sizes are too enormous. You'd need them to step on to a platform that could be released.
And that platform would need some engineering to prevent it from flipping.
To be honest the natural end point of what you get after you engineer it for safety probably is literally just an elevator platform.
A skinny person's magnets will be less close to the walls than a fat person's magnets. Tall versus short, even just body shape will affect the rate of descent. And electromagnetism is inverse-square, which is not something you can just gloss over.
And I sort of cheated by mentally running through the designs myself, like, yes, you could build a constant thing you just put people in, but, why would people want to go in the thing rather than on the thing? It is intrinsically going to be more claustrophobic in any container than being on it. So you put people on it. Then you do this, and do that, and a whole lot of safety work... and like I said, you honestly just get back to, why would anybody want this at all? Who cares if it's "really" magnets anyhow? And you just end up back at "It's a platform that descends slowly using standard elevator technology." at the end of the design process.
The frog levitation experiment required 16 Tesla. To levitate a Human is going to require hundreds of Tesla. We're talking the kind of magnetism you'll find around stars. Expensive might not even be the right word, I think you have to dedicate a portion of society to the task of building and powering the machine that can levitate one person at a time. Realistically, we learn quickly that the machine kills people instantly.
The Ride "Superman, The Escape" at six flags magic mountain in california is a Linear Induction Motor driven ride that pushes the ride car using electromagnets. At both ends of the track are some serious magnets that if something fails will stop the car that has a metal fin the electromagets act on in a fail-safe way using that principle. I'm not privy to the exact details, but knew some of the designers. This was built in the mid-90s. You can see the one end in this picture. https://rcdb.com/140.htm#p=264
I've seen it in testing with a power off e-stop and the car just comes to a rather sudden halt, and they have to get it out with a winch slowly. Pretty good safe solution, though not a feature of normal ride operation.
A large plexi ball with embedded magnets, and a (also plexi or glass?) tower with copper or aluminum spaced out in stripes (would that work? It should?) so one could see through it all, and especially see that there is a lot of air between tube and falling ball.
That would be scary, and a cool experience, I think.
How would you dissipate the heat generated from the eddy currents? You aren't just falling slowly, you're resisting gravity which causes work and that energy has to come from and go to somewhere.
200m of height difference (a lot!) only translates to 0.5°C in temperature difference worth of potential energy (assuming the object has the specific heat of water).
And that ignores the fact that you would have that heat mainly in the stationary conductor (copper tube), not the magnetic falling object (person with magnets strapped on).
There are challenges brought by the very powerful magnets required, as other posters point out. Think about the safety procedures for even approaching an MRI machine.
I wonder if you could do this with passive air pressure alone. That way, no strong magnets required and you can use clear building materials so you can see out.
A simple model:
Imagine a hollow cylinder (like a pipe) with one end capped. It is standing vertically, with the capped end down. Now imagine the ride "vehicle" is a plexiglass sphere. If you drop the sphere into the cylinder from above and the plexiglass sphere isn't a perfect fit to the inside diameter of the cylinder, the sphere will fall through the pipe and eventually hit the capped bottom of the pipe. How fast the sphere slows in the pipe will be some function of how much clearance there is between the sphere and the ID of the pipe.
There are elevators that work sorta like this, but with seals and much slower, pneumatic vacuum elevators (https://www.youtube.com/watch?v=QccXIj0k5qg). At least, they do basically this in one failure mode.
Ok, great. But we want a fun ride. What about, instead of a pipe, a big funnel? Could be straight-walled or shaped like the bell of a trumpet or the barrel of a blunderbuss (i.e., fans out at an increasing rate). Now, since we don't need you exactly in a tight-fitting pipe (at least at the beginning), we can just drop you at the funnel, rather than starting you carefully placed within the pipe. So you get some amount of free-fall inside a clear plastic sphere.
Okay, that's a ride! My gut says that there should be some combination of funnel shape, sphere size, and possibly vents in the side of the funnel that allows us to control the rate of deceleration as you approach the ground such that the human(s) inside the sphere are unharmed and had a lot of fun.
I'm struggling to see how it would be very interesting compared with, say, a rollercoaster or a drop tower, where there are external frames of reference, and full 1G (or more) acceleration / weightlessness.
I imagine the experience would be about as interesting as taking an elevator down a tall building. Maybe I am missing something, though?
You could make the first part of the experience free-fall (throw people with a magnet strapped on down a tube that is conductive only near the bottom).
I think the big problems are that you need a hefty magnet (which is inherently dangerous) and you can't really split up the magnets over the body (because that is INSANELY dangerous), so you experience that same thing that could be achieved via bungee cord/harness.
You would also need to limit (lateral) movement quite a bit, to get reliable braking...
A x-shaped magnet assembly strapped to the back could work, but you probably could not allow the tube being all that much bigger in diameter than that backpack...
edit: If you allow any fall configuration different from feet-first, the terminal velocity has to be pretty low to reliably not kill people, too. But you could make this work with a net, I think...
Give people an MRI on the way down. Boom. I won’t even charge you for this truly inspiring thought.
I'm inclined to agree that his likely is one of those situations where despite the novelty maybe provided by the new tech, old tech does this job better or at least sufficiently that you still end up using old tech.
> I think the experience of falling slowly down a tube would be very interesting.
So, like an elevator?
I agree that Lenz's law is pretty neat. In high school my electronics class got to visit a research MRI and bring in coils of wire and other objects to experience it first-hand.
Pretty sure it can be done with aluminum pretty well, so it probably wouldn't be that expensive compared to some rides.
You couldn't use multiple magnets on the person or they might smash together, and you'd have to be very careful guests stayed apart, and that they didn't have anything magnetic in their pockets to go flying towards the magnet and hurt them.
You could do it with air pressure, like indoor skydiving in a confined area, but it would probably be loud and somewhat unpleasant.
Since people aren't magnetic it would probably feel exactly the same as jumping with a harness on a cable instead of with magnets.
Unless you used the frog levitation thing but that's a different effect and would probably be really expensive
There is no way you could put the magnets on the rider. Variance in body sizes are too enormous. You'd need them to step on to a platform that could be released.
And that platform would need some engineering to prevent it from flipping.
To be honest the natural end point of what you get after you engineer it for safety probably is literally just an elevator platform.
Why would body size variation affect anything? You could just have enough magnets to slow the heaviest person enough to be safe.
Although you might wind up with a hundred pound full body suit or something
A skinny person's magnets will be less close to the walls than a fat person's magnets. Tall versus short, even just body shape will affect the rate of descent. And electromagnetism is inverse-square, which is not something you can just gloss over.
And I sort of cheated by mentally running through the designs myself, like, yes, you could build a constant thing you just put people in, but, why would people want to go in the thing rather than on the thing? It is intrinsically going to be more claustrophobic in any container than being on it. So you put people on it. Then you do this, and do that, and a whole lot of safety work... and like I said, you honestly just get back to, why would anybody want this at all? Who cares if it's "really" magnets anyhow? And you just end up back at "It's a platform that descends slowly using standard elevator technology." at the end of the design process.
The frog levitation experiment required 16 Tesla. To levitate a Human is going to require hundreds of Tesla. We're talking the kind of magnetism you'll find around stars. Expensive might not even be the right word, I think you have to dedicate a portion of society to the task of building and powering the machine that can levitate one person at a time. Realistically, we learn quickly that the machine kills people instantly.
So it wouldn't just require the same 16 tesla acting over a larger volume?
The Ride "Superman, The Escape" at six flags magic mountain in california is a Linear Induction Motor driven ride that pushes the ride car using electromagnets. At both ends of the track are some serious magnets that if something fails will stop the car that has a metal fin the electromagets act on in a fail-safe way using that principle. I'm not privy to the exact details, but knew some of the designers. This was built in the mid-90s. You can see the one end in this picture. https://rcdb.com/140.htm#p=264 I've seen it in testing with a power off e-stop and the car just comes to a rather sudden halt, and they have to get it out with a winch slowly. Pretty good safe solution, though not a feature of normal ride operation.
The Vancouver SkyTrain also uses LIMs.
A large plexi ball with embedded magnets, and a (also plexi or glass?) tower with copper or aluminum spaced out in stripes (would that work? It should?) so one could see through it all, and especially see that there is a lot of air between tube and falling ball.
That would be scary, and a cool experience, I think.
Plus a means or magnet arrangement to prevent tumbling. But it would be very dangerous getting in and out without special engineering.
Hm, like a door? :-)
I really like that approach-- you could also increase the conductive stripe density towards the bottom, for a more free-fally experience at first.
This sounds like a really fun ride, actually.
How would you dissipate the heat generated from the eddy currents? You aren't just falling slowly, you're resisting gravity which causes work and that energy has to come from and go to somewhere.
That would be completely negligible I think.
200m of height difference (a lot!) only translates to 0.5°C in temperature difference worth of potential energy (assuming the object has the specific heat of water).
And that ignores the fact that you would have that heat mainly in the stationary conductor (copper tube), not the magnetic falling object (person with magnets strapped on).
https://www.youtube.com/watch?v=eJGtoTc4VHY isn't the break of these work that way, maybe you can put multiple coils to slow them quickly in the midway making coils stop obvious? https://www.youtube.com/watch?v=av-WqguS8UI found this
You might have experienced it! Drop towers use eddy current brakes to slow down.
There are challenges brought by the very powerful magnets required, as other posters point out. Think about the safety procedures for even approaching an MRI machine.
I wonder if you could do this with passive air pressure alone. That way, no strong magnets required and you can use clear building materials so you can see out.
A simple model:
Imagine a hollow cylinder (like a pipe) with one end capped. It is standing vertically, with the capped end down. Now imagine the ride "vehicle" is a plexiglass sphere. If you drop the sphere into the cylinder from above and the plexiglass sphere isn't a perfect fit to the inside diameter of the cylinder, the sphere will fall through the pipe and eventually hit the capped bottom of the pipe. How fast the sphere slows in the pipe will be some function of how much clearance there is between the sphere and the ID of the pipe.
There are elevators that work sorta like this, but with seals and much slower, pneumatic vacuum elevators (https://www.youtube.com/watch?v=QccXIj0k5qg). At least, they do basically this in one failure mode.
Ok, great. But we want a fun ride. What about, instead of a pipe, a big funnel? Could be straight-walled or shaped like the bell of a trumpet or the barrel of a blunderbuss (i.e., fans out at an increasing rate). Now, since we don't need you exactly in a tight-fitting pipe (at least at the beginning), we can just drop you at the funnel, rather than starting you carefully placed within the pipe. So you get some amount of free-fall inside a clear plastic sphere.
Okay, that's a ride! My gut says that there should be some combination of funnel shape, sphere size, and possibly vents in the side of the funnel that allows us to control the rate of deceleration as you approach the ground such that the human(s) inside the sphere are unharmed and had a lot of fun.
Physics nerds: what say you?
Just use an elevator platform, or even a belt? What is the unique experience you hope to achieve?