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Perpetual Skislope
the hollow room writes: "How about skiing on a never ending slope? A story at New Scientist suggests that some fool is going to try to build one of these. Built like a huge tilted record player, it can spin at up to 30 km/h.
Any takers?"
You travel up the hill, go into the equipment area, get sprayed with man made snow, and turn into a mogul.
I want to see it built just for the entries into the Darwin Awards it will generate.
"As God is my witness, I thought turkeys could fly." A. Carlson
I learned how to ski as a kid riding a huge conveyor belt made out of a big rug in the bottom of a sporting goods store. It doesn't sound like much, but it was fun as a kid. The coolest part was that you could turn it on and off with a garage door opener type gadget. I always wanted to turn it up really fast and see how much speed I could get up tucking, but my ski instructor wouldn't let me. Now that I look back, tucking really wouldn't matter. There's no wind resistence to worry about when you aren't actually moving.
...that it's all downhill from here.
When this thing is running at full tilt, how the hell do you get off it? Or worse yet, where do you go if you fall, as is sure to happen.
:p Be nice if the article was more than a brief overview.
Seems to me there's a lot of issues with physics involved as well, ignoring the problems of getting the thing to actually operate.
People learn to ski on solid, non moving surfaces. What happens when you try to stop.. do you overbalance and fall down? Or how about the race track problem.. you're always turning left, cuz if you turn right you run into the wall.
Basically I see this thing creating more questions than solutions.
Movies of a working ski-trak!
Okay, it's just a model but they answer the everyone's question about getting on and getting off - there's a stationary area in the middle
The problem I'm seeing here is pretty major. If you take a 3000m ski run and compress it into a 300m run, there's still going to be 3000m worth of "snow damage" per skier/run, but it will be compressed into 300m of distance. So the snow is going to be 10 times as chopped up in any one place. And real ski resorts have multiple runs that reduces the traffic on any one run... to even begin to pay for this thing it's going to have to be packed.
Oh wait, that was steps...
"Scientists debated for weeks over whether 33, 45, or 78 rpm was the best speed for skiing"
If you think about it, there are natural perpetual slopes: Standing waves (wakes?) on rivers.
I even found a very cool video (8MB) demonstrating riversurfing on the Eisbach in Munich.
So couldn't this somehow be used so that someone could end up walking to school, in the snow, uphill BOTH ways?
"We shall show mercy, but we shall not ask for it" -- Winston Churchill
No chairlifts sounds nice. If you out-ski the turntable you just pull off to the side and ride to the top, then hit the trail again.
But chairlifts also meter traffic. I'm talking out my butt here, but I'm sure that ski slopes do some kind of calculations involving skiers/hour and trail capacity. Without a traffic limiter, the turntable could get 'too busy' on heavy days.
If you've never operated an LP phonograph -- the skating force is due to the differential friction on opposite sides of the needle on a phonograph, and tends to draw the needle inward toward the center of the record. It's large enough to cause a needle to skip, bump bump bump, right over the grooves unless a counteracting force is applied. Low-end turntables used springs to pull the needle outward and combat the skating force; high-end turntables used little weights with little mechanical linkages that were designed to match the changes in the skating force with radius.
You can see skating force in action at the bottom of a teacup if there are a few tea leaves floating around down there at the bottom. The tea leaves (after they're waterlogged) sink, so spinning the tea in the teacup "ought" to make them fly outward in the local gravity field. But in fact, tea leaves at the bottom of the cup tend to pile up in the center (when you spin the tea). Counter-intuitive and mysterious, until you realize that the leaves are also dragging on the bottom of the cup and therefore are subject to the skating force.
I'm pretty sure anyone who is capable of carving (ie., has at least a couple years experience) wouldn't waste their time on this. It sounds like a tool that would be more successful at teaching beginners who are too afraid to actually start moving on real snow, since this thing could be stopped whenever they want.
That brings up an interesting point though: how are you supposed to learn to turn properly if you move at different speeds when you turn left or right? One of the biggest problems I had when learning was that I was better at turning left than right for a long time, and it really hurt me when skiing tougher terrain like moguls and deep snow. Eventually I figured it out, but that's a problem that will have to be resolved before I would send my kids to learn on this.
I'm not sure I get the physics involved in this assertion, but it seems like it you could discourage people hitting the spindle by building up the middle of the disk such that you have to ski "uphill" to get to it.
I play Nerd-Folk!