Perpetual Skislope 241
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?"
And when you fall on your ass... (Score:4, Funny)
I want to see it built just for the entries into the Darwin Awards it will generate.
Re:And when you fall on your ass... (Score:3, Funny)
Ever see the opening to the Jetsons where George falls on the treadmill? Like that, except with snow.
-Russ
hmmm... (Score:2, Interesting)
Re:hmmm... (Score:2)
Picture an "up" escalator.... now start walking down it... Same principle.
And as for being physically possible (the whole tilted record player idea), there are small amusement park rides that already do the same thing.
I wonder if we'll be able to play B-sides on this thing, though
The perpetual slope already exists (Score:5, Interesting)
Olympic Sports, Northgate? (Score:1)
Re:Olympic Sports, Northgate? (Score:1)
Re:Olympic Sports, Northgate? (Score:2)
Re:Olympic Sports, Northgate? (Score:2)
Re:Olympic Sports, Northgate? (Score:2)
Re:Olympic Sports, Northgate? (Score:2)
Re:The perpetual slope already exists (Score:5, Insightful)
What this guy has in mind is like an upended record, on a much larger scale, more terrain to move about in, but ultimately still what I would consider a dull experience. Probably good for teaching beginners and little else, since the inside and outside of the track would be moving at different rates you'd get pretty good at turning one way, but would find difficulty adjusting to a real slope. Nothing like screwing up your motor skills and equilibrium.
IMHO it looks terrible. I'm sure it'll be a hit.
Re:The perpetual slope already exists (Score:2, Informative)
Your guess is wrong - it's the drag skiiers are trying to reduce when they tuck. These guys are going over 60 mph - wind resistence is a big deal.
Re:The perpetual slope already exists (Score:1)
It just doesn't work that way. A disc and a sphere of the same weight will simply not roll downhill at the same speed, even in a vacuum. Besides, the very act of lowering one's center of gravity 1.5 feet would have a definite impact on momentum.
Re:The perpetual slope already exists (Score:3, Informative)
You are comparing different issues. The skiier is not rolling. If the skiier were trying to roll down the hill, then you would be correct, but the momentum that you're describing is rotational momentum, not translational. With translational momentum, it doesn't matter. A proper comparison would be to push an object across a table (like say your CPU and your monitor); they have very different geometries, but the only forces acting on them are your push and the friction of the table (until you get to high speeds when wind resistance matters).
Re:The perpetual slope already exists (Score:1, Informative)
You're right that disc and a sphere will not roll downhill at the same speed. That's because the moment of inertia changes. However, a skier does not roll -- he slides downhill.
Just write down the equations for potential and kinetic energy and you'll see that changing the center of gravity won't change shit as far as the speed goes.
Moving the center of gravity up or down changes the potential energy, but since its reference level can be chosen arbitrarily it will have no effect in how much potential energy can be converted to kinetic energy.
Re:The perpetual slope already exists (Score:1)
He didn't tell you this, but it's true.
A disc and a sphere of the same weight will simply not roll downhill at the same speed, even in a vacuum. Besides, the very act of lowering one's center of gravity 1.5 feet would have a definite impact on momentum.
Where do I start;)
Okay, there's a difference between angular momentum and linear momentum. A skier slides (linear), a disk or a sphere will roll (angular). To calculate linear momentum (like the momentum of a skier): p = mv, where p is momentum, m is mass, v is velocity. Lowering center of gravity has no effect on momentum (or acceleration, for that matter). Decreasing drag at 60MPH, however, has a great deal of effect.
Re:The perpetual slope already exists (Score:1)
Re:The perpetual slope already exists (Score:2)
Re:The perpetual slope already exists (Score:2, Informative)
It is not the same. Unless you spin like a figure skater when you ski down the hill.
"The physics of a tight, compact body with a low center of gravity..."
The low center of gravity helps when you are trying to turn (change direction), but the biggest advantages to tucking deal with lowering wind resistance and tensing your muscles like springs to react faster.
Re:The perpetual slope already exists (Score:2)
Re:The perpetual slope already exists (Score:1)
Re:The perpetual slope already exists (Score:2)
The only situation in which you'd care about position is for angular momentum, which you don't have at all, because you're not turning.
Re:The perpetual slope already exists (Score:1)
You know how figure skaters pull their arms into their bodies to increase their rotational momentum?
Angular momentum is always conserved, it's actually the angular velocity (spinning) that's increased when rotational inertia (resistance to spinning) is decreased (by bringing in the arms).
My guess is that tucking has as much, if not more, to do with momentum than aerodynamics.
The momentum of a system (skier) is unaffected by interactions withing the system (standing up or tucking). So it technically has nothing to do with momentum.
Re:The perpetual slope already exists (Score:2)
Re:The perpetual slope already exists (Score:2, Funny)
Anyone else have a guess?
Ha ha ha (Score:2)
Since you have obviously never skied perhaps the following story will be illustrative:
I was at Alta one day and it was blowing so hard that the only way to get downhill was to get into a tuck. If you stood upright the wind would actually blow you UP the mountain. After two runs they shut down the lifts since the chairs were swinging wildly. I guess I could have simply started at the bottom and skied up the hill with the wind blowing my up and then come back down in a tuck but the ice that had formed on my beard was telling me that I should stay in the lodge.
p.s. What does sort of "rotational momentum" does a object that is not rotating have?
Let me be the first to predict... (Score:5, Funny)
Re:Let me be the first to predict... (Score:1)
Why use a rotating disk? (Score:1, Insightful)
Re:Why use a rotating disk? (Score:2, Informative)
Re: disk advantage (Score:2, Interesting)
Re: disk advantage (Score:3)
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.
Re:Why use a rotating disk? (Score:2, Insightful)
Re:Why use a rotating disk? (Score:2)
This is actually not new (Score:2, Redundant)
Newbies also uses this to learn how to ski... I know of some places in Holland (of all places) that they have this - It's like another post here says, it's a big rug you ski on, the instuctor is at the bottom directly in front of you, telling you what to do...
Never tried it myself though. I don't plan to turn pro, but I do enjoy the occasional trip to France to ski the alps
Re:This is actually not new (Score:1)
I know of some places in Holland (of all places) that they have this
Well with a country as flat as ours, where else are we going to practise? ;-)
Recently though, this type of facility is getting more popular (Snowplanet [snowplanet.nl]).
No substitute for the real thing though
Please read the article.. (Score:2)
I'm really wondering why they had to make it a rotating structure though; I don't see why they couldn't use a conveyor belt-like design. People will get dizzy this way.
Re:Please read the article.. (Score:1)
Remember, they are constantly reconditioning the surface.
However, with a belt, appx. 1/2 of the surface would be upside-down at any given time.
This would make it difficult (impossible?) to use snow as the ski medium.
Re:Please read the article.. (Score:2)
And that means they would reach the other side of the slope and start to slip down backwards...
Re:Please read the article.. (Score:1)
what if the "record" gets a "scratch" ;) (Score:5, Insightful)
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.
Re:what if the "record" gets a "scratch" ;) (Score:2, Funny)
If you can perpetually ski, can you perpetually fall?
Re:what if the "record" gets a "scratch" ;) (Score:2)
A good use... (Score:2, Funny)
Built like a huge tilted record player, it can spin at up to 30 km/h. Any takers?
Couldn't we somehow merge all those screwed-up IBM Death^H^H^HskStar drives into a pseudo Beowulf cluster that would spin that fast?
Of course, I wouldn't want to be skiing on it when a few drives totally die
EricKrout.com officially endorses Ximian GNOME [ximian.com]
always left turn (Score:1, Funny)
Re:always left turn (Score:1)
Re:always left turn (Score:1)
Eugoogly? (Score:2, Funny)
Either way, eugoogly is pretty funny. 'Yougooglie'
kind of boring (Score:1)
Re:kind of boring (Score:1)
Re:kind of boring (Score:1)
How do I get on? (Score:2, Insightful)
It would also get pretty boring to ski around in a circle for hours on end... no new scenery. If they put up a big contiguous screen along the edges, and maybe some of the sky too, to prevent you from getting quite so dizzy and provide some additional entertainment.
Then again you could also just go VR skiing and never have to go outside or worry about all these physical limitations.
Re:How do I get on? (Score:2)
w/skiis it would be obviously harder but the same idea could apply
This is not new (Score:1)
Tom
Movies (Score:4, Informative)
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
Doesn't the snow get worn out? (Score:5, Interesting)
Re:Doesn't the snow get worn out? (Score:1, Flamebait)
Re:Doesn't the snow get worn out? (Score:2)
Re:Doesn't the snow get worn out? (Score:1)
I might worry about some of the snow melting (if it wasn't getting too compressed, it'd have to go somewhere), but an adequate run-off system at the outer edge of the disc should suffice.
Re:Doesn't the snow get worn out? (Score:2)
Geek answer: simulator (Score:1)
BTW, a google search turns up a number of links to simulators which use treadmills (as has been mentioned earlier as an idea).
Google link [google.com]
Re:Geek answer: simulator (Score:2, Funny)
1. laughing at that guy, who just crashed, as you ride the chair lift
2. the sense of irony as you face-plant into a snow drift
3. extracting snow from your thermal underwear
4. marching up the hill to retrieve your skis
5. realizing those guys in the chair lift are laughing at you.
uhh..not me (Score:2, Insightful)
I think I'll let them work the bugs out first.
Hang on... (Score:5, Funny)
Oh wait, that was steps...
So um... (Score:2)
Anyone else thinking of an embedded Linux system to recognized where a skiier is on the hill and adjust the speed accordingly? =)
Indoor Skiing (Score:2, Informative)
Indoor Skiing [goski.com]
rotational speed is important (Score:5, Funny)
Its missing a critical part of skiing. (Score:1)
Sounds like a winter wonderland for lawyers.... (Score:2, Interesting)
I'm just not convinced that taking EVERY naturally occuring (and read "free") effect of nature and turning it into a private, man-made, man-controlled, homogenized, and lawyer safe sport is a good thing. It comodotizes nature, and creates a situation which blurs the distinction between real life and "Real Life (tm)"
I see this trend with surfing too, artificial wave generators, controlled "fun-parks" where people have to "Pay-per-Wave"....Yeah, Mother Nature does not create the exact same wave every time, but that's the fun of the sport!
Both of these are, in my view, attempts by corporations to get people to pay for something that's inherently free. Surfing for instance...paddle out, ride back for free....Sking too, climb to top of hill, slide to bottom for free...Only with sking, you do pay for the lift (but you can walk for free too)
Perhaps I'm not looking at the best side of this though.....the rotation of the hill might counteract the rotation brought on by too many Irish Coffee's at the bar! Now that would be something.
Natural equivalent (Score:5, Interesting)
I even found a very cool video (8MB) [uni-magdeburg.de] demonstrating riversurfing on the Eisbach in Munich.
Re:Natural equivalent (Score:2)
The old saying... (Score:4, Funny)
Re:The old saying... (Score:1)
That will not work (Score:2, Insightful)
Re:That will not work (Score:1)
ski patrol rescues (Score:1)
Re:ski patrol rescues (Score:1)
This is not true! The skiers have NO momentum. The are not moving. They might have centripical forces, but ONLY if they angle towards the outside edge of the disk. As long as they keep aimed perpendicular to the radius (which will feel like 'turning'), they won't go flying anywhere, and will in fact remain stationary. If they speed up a little too much, then they will naturally move towards the edge, but as long as they aim perpendicular to the radius, they won't build up centripical force.
Re:ski patrol rescues (Score:2)
Grab.
Chairlifts... (Score:4, Insightful)
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.
Re:Chairlifts... (Score:2)
Make both sides go downhill.
--Blair
"Wait for it."
Variation on this idea already done in Japan (Score:1)
Appologies to Derick Zoolander (Score:1)
Left (Score:1)
ive seen it done. (Score:1)
It was basicaly a large carpet on a large coveigher belt making an endless loop of carpet.
think huge treadmill that slops down and rolls upwards. i think it tilted side to side and up and down for vaitation in slope and whatnot. it was really kinda cool then.
a large disk just doenst sound like a good idea.. the inner area of disk would prolly suffer much more wear and tear sinice it goes faster. not to mention the uneven speed across the surface of it.
Re:ive seen it done. (Score:2)
No... there is no snow involved. Alot of people have already mentioned this and have called it "carpet" for lack of a better term, but this isn't your average gray indoor-outdoor... it's really more like a foamy shag. It's enough to allow you to cut directly on the surface. I think it actually solves alot of problems that snow on any kind of conveyor or turntable would cause, but I wouldn't go on it, for the sake of my edges.
Subject to the ``Skating Force'' of LP days (Score:5, Interesting)
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.
Tealeaf problem (Score:2)
When the tea is spinning steadily, the leaves are honogeneously distributed near the bottom. The centrifugal tendencies are cancelled by the pressure gradient: the surface of tea becomes parabolical, so at the bottom there is greater pressure towards the edges.
However, when you stop spinning the tea, viscosity starts to slow down the rotation. The bottom layer will, for a while, rotate slower than the rest of the tea. But the parabolical shape of the surface is still there, along with the pressure gradient it causes. Therefore, at the bottom layer, the inward forces are greater than the necessary centripetal force, so the leaves are pushed to the center.
Do try it, it's essential to notice the difference between steady spinning and slowing down.
So have it slope up towards the middle? (Score:4, Insightful)
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.
Re:Subject to the ``Skating Force'' of LP days (Score:2)
Seriously though, I don't know whether the skating force would be an issue; the LP and tea-leave examples have very little friction downwards as compared to skiing, so that effect might not be as pronounced. (I could be completely wrong, though
I think the constant-left-turn thing would take a lot of the fun out of it. And the fact there's a place to get off in the middle doesn't help you a lot when you crash. Crawling from the outside to the inside, while going uphill then downhill, with other people whizzing by, sounds like a disaster in the making. Cute idea, but sounds impossible to execute successfully.
-me
What about centripetal force? (Score:2)
30km/h ~= 10m/s
The radius sounds like it's a little less than 100m (if 300m is the circumference of a half of the circle
a=v^2/r
So acceleration at the edges will be about 1 m/s^2
You'll have to add or substract that to the 9.8m/s^2 vector.
Actually, in retrospect of this calculation, I think it will be that 9.8m/s^2 accelleration vector spinning like a top that will have the worst effect on the snow. First you're an upslope, now you're a downslope!
Hope they groom it well.
Tux Racer? (Score:1)
Uhm... physically impossible (Score:1)
Oh yeah (Score:2)
Japan? (Score:2)
Maglev bobsled (Score:2)
Their business plan also points out that global warming increases their potential market. [ski-trac.com] May take a while for that to kick in, though.
The Anaheim, California Gotcha Glacier [google.com] project was somewhat similar, minus the big turntable, but financing fell through late last year. Somehow I expect that may happen to this project, especially since the first site is planned for Wales, instead of near some major urban area.
These guys have bad timing. Three years ago, you could have IPOed something like this. Today, forget it.
Re:Misses the key things that make skiing fun (Score:1)
It has a constant RPM - but the speed of the skier over the ground depends on how far away from the centre of the disk they are. if the skiable area is sufficiently wide, the difference in available speeds could suit a whole range of skiers abilities.
Re:Uhm... no. (Score:1)
I know it is a model, not the real thing, but watch Movie #1 [ski-trac.com].
The inventor seems to think skiers will be able to ski where they want across the entire moving area.
Re:Misses the key things that make skiing fun (Score:2, Informative)
Re:Not enough time (Score:2)
With some people pointing out the boredom of a repeating slope, option #1 has the advantage of dynamically creating moguls and other random surface formations for the enjoyment of variety seeking alpinists.