 Poster: A snowHead
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Report from Science Daily.
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"When you throw something slowly to a child, you think you're doing them a favor by trying to be helpful," says Terri Lewis, professor of psychology at McMaster University. "Slow balls actually appear stationary to a child."
This explains why a young child holding a bat or a catcher's mitt will often not react to a slowly tossed ball, prompting flummoxed parents to continue throwing the ball even slower.
By adding a little speed to the pitch, Lewis and her team found that children were able to judge speed more accurately.
"Our brain has very few neurons that deal specifically with slow motion and many neurons that deal with faster motion," says Lewis. "Even adults are worse at slow speeds than they are at faster speeds." |
The full study apparently hasn't been published yet. However, in the interview for CBC radio, we find that the experiment wasn't based on ball throwing at all.
(The interview is on Segment 2 of the broadcast- fast forward your RealPlayer to minute 17)
The study was apparently based on tracking of stripes across a computer screen. The statement made is that at speeds equivalent to an object moving across the visual field at 1/4km/h at one meter distance children are three times worse than adults, the difference significantly diminishing at speeds equivalent to 1km/h (viewed from 1 meter away).
Is this significant to parents of protoskiers and future pros?
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Let us assume that a natural avoidance distance is 2 ski turn radii, probably 18 meters for junior skis. The equivalent speeds across the visual field are then 4,5km/h and 18km/h.
The scary part comes if we compute the case of a 1m wide rock 18m away. To achieve the tested angular velocities of the top or lateral edge of the rock as it increases in apparent size, the velocity of the child towards the rock is 12,9km/h and 51,6km/h respectively.
Feel free to check the maths.
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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comprex, thanks for the info, this means I HAVE to throw the rugby ball to my youngest VERY quickly indeed 
What are the ages of the test groups BTW
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You need to Login to know who's really who.
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Maths aside, I've seen four year old skiers that can turn on a sixpence. Reaction times that would put many adult snowsports enthusiasts to shame. Eye brain coordination that means they can thrash their parents at virtually any computer game  . So where does that fit in?
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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Well, I'm not sure that's just children. In my cricketing days, I was far more more comfortable against faster bowlers. (OK, I never got to face anyone like Steve Harmison). Against slow bowlers, a loopy trajectory is hard to pick (especially if the ball spends a significant amount of time above the batsman's eyeline) and you have time to change your mind several times before playing the shot - often resulting in neither playing forward nor back and making a terrible hash of things, in my case anyway. Against a faster bowler, you can just play instinctively and the flatter trajectory makes thing easier. Not relevant to the argument, but you can also use the pace of the ball, either in a genuine shot or with little snicks, to pierce the field without too much muscular effort!
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You'll need to Register first of course.
You'll need to Register first of course.
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laundryman, I think that's the difference between which area of your brain is doing the computing. If you leave it to your brain/body to sort it out (instinct) then it may (dependant on experience) do a better job than you if you're thinking through the whole job yourself.
How much mental input do you put into walking?
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marc gledhill, it depends how much I've had to drink! 
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This theory helps me explains why the kids say " but Dad its easier to ski when we go faster"
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You'll get to see more forums and be part of the best ski club on the net.
You'll get to see more forums and be part of the best ski club on the net.
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Frosty the Snowman, the kids are right, it is.
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So the "Drive more slowly - don't kill a child!" campaign is wrong?
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snowHeads are a friendly bunch.
snowHeads are a friendly bunch.
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Frosty the Snowman,
actually it helps explain why they don't learn if you go slower.
laundryman, good point; there was a brief mention of this in the real audio segment.
marc gledhill, no idea, study gets published in July. Notice that this only relates to visual field perception, not kinesthetic learning, say, and that it is based on statistical groups. If you believe temporal centers get developed through use, maybe you should send the kids out with a football?
PG, the study was (virtually  ) done with computer games! Remember, the issue is of perception, not reflexes. You're right, however, the assumption of 2 ski radii was based upon the carved turn.
Set your own conditions. If we take all units in meters and hours, the rock example above (width 1 meter) comes to a time differentiation of
Θ(t)=atan(1/r(t))
Θ'(t)=(1/(1+(1/r^2))*(-1/r^2)*r'(t)
therefore
r'(t)= -Θ'(t)(r^2+1)
So, from the above conditions, Vkid in meters/hr, dist in meters:
Vkid1= (125/Π)*(dist^2+1), Vkid2=(500/Π)*(dist^2+1)
Pick your own distances and reaction times. Remember also that reflexes in a non-intuitive sport need to be trained for a proper outcome. It is that training that is called into question.
Last edited by snowHeads are a friendly bunch. on Tue 10-05-05 17:55; edited 3 times in total
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And love to help out and answer questions and of course, read each other's snow reports.
And love to help out and answer questions and of course, read each other's snow reports.
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maggi, I don't give an analytical expression for Voldgoat.
It's a mutivariate problem, barely numerically computable at border conditions for (time, money, drink, women, ego).
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comprex, Sorry, but pass me the thickie baton. What is Voldgoat 
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You know it makes sense.
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And mutivariate
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Otherwise you'll just go on seeing the one name:
Otherwise you'll just go on seeing the one name:
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| maggi wrote: |
| comprex, Sorry, but pass me the thickie baton. What is Voldgoat |
Adult Vkid. A function of more than one variable.
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Poster: A snowHead
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maggi, comprex is assuming everyone is familiar with the naming schemes of scientists, Voldgoat = "velocity of old goat". 
Mutivariate is a mistyping of Multivariate meaning having multiple variables. Be careful I might tell a computer joke next and everyone (especially Mrs H) will look at me pitying.
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Obviously A snowHead isn't a real person
Obviously A snowHead isn't a real person
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Just try hitting those really easy slow balls in squash 
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Well, the person's real but it's just a made up name, see?
Well, the person's real but it's just a made up name, see?
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Ian Hopkinson, my turn 
Hey, they got this far in the thread.
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You need to Login to know who's really who.
You need to Login to know who's really who.
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Scarpa, yep same as cricket. Complete mis-cues are hard to deal with - it's the slow loopy trajectory again, coupled with the spin making the ball seem distorted (I've never quite worked out why that should be so). Again, having your opponent thrash the ball and using the pace they generate whilst conserving your own effort is a useful tactic for an old g1t like me.
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Anyway, snowHeads is much more fun if you do.
Anyway, snowHeads is much more fun if you do.
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You'll need to Register first of course.
You'll need to Register first of course.
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maggi, I'm not as good at typing at 1:35 am as I thought.
This could have been subtitled the 'Crowded Beginner Piste' thread, and I'll admit to trolling for the views of some of the instructors who post here.
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FAQ
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