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Why roller coaster loops aren’t circular anymore
- bl0b 4y agoI think never having considered this type of thing is why I could never make a sweet roller coaster tycoon coaster that didn't make everyone throw up.
- jorgesborges 4y ago> More people paid to watch others ride these early coasters rather than ride themselves I had no idea roller coasters have been around this long. The photos are laugh-out-loud terrifying. I was shocked that anyone would pay to ride them until I read the quote above. Now it makes sense. I’d pay to watch that too!
- jollybean 4y agoIn that era, there weren't even seatbelts on cars. We used to have a much different view on systematic rare danger.
- akira2501 4y agoIf you're trading a horse for the car, a seatbelt might not be the first thing you'd think of. I don't think our views on danger have changed, it's just that any new technology requires a period of adjustment to it.
- jollybean 4y agoOur views have changed. We used to throw lawn darts, have fireworks, guns all over. Not even helmets on motorcycles. When I was a kid, we used to rid maybe 6 kids in the back of a pickup truck flat bed. That was normal. It would not only be illegal today, but probably considered very immoral. Hockey players didn't even wear helmets, not even the goalies (!). Nobody wore helmets when I grew up skiing, now almost everyone does. We are considerably safer about everything today.
- space_fountain 4y agoIdk how old you are, but I have ridden on public roads in the back of a pickup certainly as late as the 2005 as a child. I think it might be more common than you think in some parts of the country
- CSMastermind 4y agoThat's still going on today in many parts of the country, I literally saw a truck driving down the road with kids in the back last week. Likewise, I've never once worn a seatbelt in an NYC taxi.
- bawolff 4y agoWe also used to knock on wood to prevent bad things happening. I think an argument could be made that we shifted from interventions that dont work to interventions that do.
- jollybean 4y agoWe still knock wood. We have more science, more education. 10% of kids under age 1 would die at the turn of the century (1900), which means, everyone knew a family with a child that had died, and that's traumatic. Our views of safety and risk have evolved. My grandfather, he worked in a lumber camp, the stories ... my god. We also react to it differently now. Even in our language i.e. 'I feel unsafe' or people talk about 'harm' or 'violence' with just language.
- edejong 4y agoWe have a very substantial part of the population becoming chronically ill after an infection of a disease labeled “mostly mild”, yet we decided low-key interventions such as masking and air filtration are not worth it.
- 2Gkashmiri 4y agoWhen I was a kid, we used to rid maybe 6 kids in the back of a pickup truck flat bed. where i live, because of paucity of transportation means, it is not uncommon to have the back door of a car straight open and 3 kids sit there, dangling their feet. that is considered very normal in these parts of the world.
- mgdlbp 4y agoHaving first read your comment, the photo wasn't as bad as I expected. The supports don't look too unreasonable for a single wooden car with two passengers. Modern trains are an order of magnitude heavier--~20 people and a gross weight of ~20 tonnes. A video of the coaster in the photo exists (the playback framerate seems somewhat too fast): https://commons.wikimedia.org/wiki/File:Flip_Flap_Railway_early_film.webm https://commons.wikimedia.org/wiki/File:Flip_Flap_Railway_ea... Modern tubular steel rails also allow for rickety-looking yet safe single-car coasters: https://commons.wikimedia.org/wiki/File:Rat%C3%B3n_Vacil%C3%B3n.jpg https://commons.wikimedia.org/wiki/File:Rat%C3%B3n_Vacil%C3%...
- jzl 4y agoOne of the most mind-blowing images on Wikipedia is this one of the first ever Ferris Wheel from the Chicago World's Fair in 1893: https://upload.wikimedia.org/wikipedia/commons/6/68/Chicago-ferris-wheel.jpg https://upload.wikimedia.org/wikipedia/commons/6/68/Chicago-... Note how large the cars relative to the tiny people standing in them. This thing was unimaginably massive. It's easy to think of 1893 as being before the modern technological era, but we were more modern than most people like to think.
- maverick2007 4y agoCertain modern(-ish) roller coasters do have more circular loops than others. Specifically Schwarzkopf[1] coasters are famous for having more circular loops (and the more intense positive Gs that come with it). Anyone in the Bay Area might remember Zonga[2] at Six Flags Discovery Kingdom which featured the more circular loops. Also maybe of interest is Blue Flash [3], a backyard roller coaster that has a loop that reminds me of old school circular loops. [1] https://rcdb.com/6844.htm https://rcdb.com/6844.htm [2] https://en.wikipedia.org/wiki/Tsunami_(roller_coaster) https://en.wikipedia.org/wiki/Tsunami_(roller_coaster) [3] https://www.atlasobscura.com/places/blue-flash-backyard-roller-coaster https://www.atlasobscura.com/places/blue-flash-backyard-roll...
- Doxin 4y agoHonorable mention for the ill-advised looping slide at action park[0] [0] https://i.imgur.com/Bs4Hs3E.jpg https://i.imgur.com/Bs4Hs3E.jpg
- kurupt213 4y agoThat would be a hard pass from me
- treis 4y agoAm I high or is the picture of the flip flap railroad loop decidedly not circular?
- function_seven 4y agoYou’re high. But also the photo was taken at an angle to the track, so it’s not gonna trace out a circle on your screen.
- TylerE 4y agoNo, he’s not wrong. The exit is about 20 ft further forward than the entrance. A true circular loop the entrance and exit would be directly side by side.
- treis 4y agoI'm not high now and I read the article they cited for that fact. Nowhere in the article does it say the first loops were a circle. In fact, it says the opposite: >New York City's Coney Island, home to several amusement parks, followed with its own looping coaster in 1901. Using an ellipse rather than a circle for the loop,
- nostrademons 4y agoNote that the narrow-loop shape in modern roller-coasters means that the tightest curve is at the top, where the G-forces are partially countered by gravity. That's an 1-G that they can subtract, and it means the radius can be significantly larger on entry to the loop, resulting in smaller G-forces.
- mc32 4y agoAlso by the time you get to the apex it’s going slower than when it entered the loop.
- SV_BubbleTime 4y agoI’m having trouble imagining a scenario where this is not the case.
- thereisnospork 4y agoHere's a 1 reasonable and 1 contrived example: An inverted loop, where the loop is lower than the track, and with a very long train, where the center of mass continues to decrease in height due to the part of the train not presently looping.
- liftm 4y agoRoller coaster cars with electrical motors? I somehow like the idea. Could mess with Gs in one more direction.
- cormacrelf 4y agoThis free 1g of turning force is apparently known among pilots as “God’s G”. It needn’t be produced as lift while you’re inverted at the top of a loop, so you get a good turn rate despite losing speed and hence lift as you get up there.
- dehrmann 4y agoNot just gravity, but the train also loses speed at the top, so the loop needs to tighten if you want to maintain the same force (you might not want this).
- tobtoh 4y agoIf I remember my uni engineering/calculus maths class correctly, the third derivative of position is used in planning these sort of curves. The first derivative of postion (with respect to time) is velocity. The second derivative is acceleration (ie rate of change of velocity). And the third derivative is jerk (rate of change of acceleration). And 'jerk' has to be kept below a certain threshold for humans to find movement comfortable.
- dijerido 4y agoSkateboarders in 2008 don't get this. https://www.youtube.com/watch?v=TkeCZfG_KaI https://www.youtube.com/watch?v=TkeCZfG_KaI
- salty_biscuits 4y agoJounce, crackle and pop for the 4th, 5th and sixth derivatives
- cperciva 4y agoJounce, also known as snap. Which to people of a certain cultural background explains where the names for the 5th and 6th derivatives come from.
- kristiandupont 4y agoIt feels wrong to me that pop comes after crackle. Crackle seems like the ultimate high-frequency effect. In fact, "pop" seems like it should come before "snap". But I guess it is somewhat arbitrary.
- wetmore 4y agohttps://en.wikipedia.org/wiki/Snap,_Crackle_and_Pop https://en.wikipedia.org/wiki/Snap,_Crackle_and_Pop
- keithnz 4y agoI have a t-shirt which has "don't be a" and the equation for the third derivative
- teh_klev 4y agoThis seems to be the source material: https://www.datagenetics.com/blog/march42014/index.html https://www.datagenetics.com/blog/march42014/index.html Vox re-heating a gizmodo article[0] which re-publishes (with permission) the one above. [0]: https://gizmodo.com/why-roller-coaster-loops-are-never-circular-1549063718 https://gizmodo.com/why-roller-coaster-loops-are-never-circu...
- milliams 4y agoAnd in fact Data Genetics is s great blog with loads of interesting content on maths, statistics and simulation. One that I've used as inspiration for a programming class I was teaching is his analysis of Snakes and Ladders: https://datagenetics.com/blog/november12011/index.html https://datagenetics.com/blog/november12011/index.html
- thrdbndndn 4y agoI really want to like Vox's video format but just can't. Which is a shame because they have lots of topics that are quite interesting. I can't pin down which part that I hate most, the "stylish" presentation with random SFX and virtual pen circling around, or the fact they always insert some super low quality video conference footage instead of just letting the narrator paraphrasing (I get it they're the domain experts, but still..).
- therouwboat 4y agoI couldn't watch it, I guess it felt messy and there was too much stuff going on, so it was hard to focus.
- mkl 4y agoThus is similar to corners in roads not working well when they're circular arcs. Going from straight to circular arc means your steering wheel needs to jump instantly from one fixed position to another. Using something like a linear change in curvature (i.e. a clothoid curve) is much smoother. This kind of thinking applies to other areas too: https://en.wikipedia.org/wiki/Euler_spiral https://en.wikipedia.org/wiki/Euler_spiral
- joshu 4y agofor exactly the same reasons the corners of apple products aren't just an arc. They change the tangent smoothly over time. Curiously Dubins paths do have instantaneous steering changes. https://en.wikipedia.org/wiki/Dubins_path https://en.wikipedia.org/wiki/Dubins_path
- Flankk 4y ago14 G's! That would knock you out. There's no way it was that high. I looked it up and it says they tested it on chimpanzees. I'm sure the monkeys were absolutely thrilled.
- Someone 4y agoCould be 14G for a very short period, fist when entering the loop and again when leaving it.
- mixmastamyk 4y agoI remember the Corkscrew at Knotts as a kid, no longer exists. The Revolution at Magic Mountain arrived in the late 70s with the new parabolic shape and still running. (Southern California)
- TylerE 4y agoIt does actually. It was moved to Silverwood in Idaho and has operated there very since.
- kazinator 4y agoA "G force spikes" is called a "jerk" in physics; as acceleration is the rate of change of speed, jerk is the rate of change of acceleration. The jerk is huge in transitioning from a straight track to a circular one immediately, since the acceleration goes from zero to nonzero instantly.
- Doxin 4y agoIf I recall correctly the list of derivatives and derivatives of derivatives goes like this: position, velocity, acceleration, jerk, snap, crackle, pop.
- jfzoid 4y agoThe book Curves for the Mathematically Curious ( https://press.princeton.edu/books/hardcover/9780691180052/curves-for-the-mathematically-curious https://press.princeton.edu/books/hardcover/9780691180052/cu... ) has a whole chapter about the shape used instead of a circle, complete with equations and derivation. Highly recommended
- Blikkentrekker 4y ago> G-force I looked up this term to be sure and I'm convinced it's as meaningless as I thought it was and is a strange way of saying “force” or in this case a centrifugal force.
- Doxin 4y agoG-force is just measuring acceleration in units of G. It's a commonly used measurement because you've got an intuitive feeling for what one G feels like.
- aasasd 4y agoA similar principle works in UI design and industrial design. Rounded rectangles often just slap circle arcs on the corners—but that looks unnatural because you don't get such a shape if you bend a straight rod. In this approach the turning radius changes from infinity to a constant at one point, but the proper way is to change it gradually. Bezier curves accomplish that, I think. Once you see this, you begin to notice it everywhere, just like with kerning. Apple used both ways on iPhones for rounding the phone's corners, iirc. Also I've been told that the principle applies to road turns: you don't want people to have to suddenly turn into the curve. (In related news, I wish a month of bad hiccups on Herman Tilke.)
- smugma 4y agoApple went from using roundrects to squircles a decade ago: https://99percentinvisible.org/article/circling-square-designing-squircles-instead-rounded-rectangles/ https://99percentinvisible.org/article/circling-square-desig...
- aasasd 4y agoIIRC from when I read about this concept for the first time: Apple managed to revert to bad rounding on the phone shape at some point. And probably reverted back later, but I can't confirm that. Basically, the reader is advised to check the rounding before buying their next phone.
- suyjuris 4y agoI once implemented rounded rectangles by drawing circles with regards to arbitrary p-norms [1,2] – I did not think about it at the time, but the derivatives are probably quite nice. (It did have the advantage of using the same code for rounded rectangles and for circles.) [1] https://en.wikipedia.org/wiki/Norm_(mathematics)#p-norm https://en.wikipedia.org/wiki/Norm_(mathematics)#p-norm [2] https://en.wikipedia.org/wiki/Lp_space#/media/File:Vector-p-Norms_qtl1.svg https://en.wikipedia.org/wiki/Lp_space#/media/File:Vector-p-...
- aasasd 4y ago