Wow. This has been all over the place. Not sure if it's about BOS/COM in the lateral plane only or also fore/aft ?
Too many times we are guilty of trying to fit some movement into a scalar system. It won't work. We must always consider vectors.
Run straight at a wall: the sudden reaction force from the wall will stop you.
Run at a wall at an angle: the reaction force from the wall will redirect you.
Tie yourself to a stake and run straight out. The sudden reaction force from the rope will stop you.
Tie yourself to a stake and run, redirecting yourself at the last moment, so that the reaction force won't be straight back: the reaction force will redirect you.
Continue to run while the rope is tensioned. If you run straight out, you'll just wear your shoes and not move. If you run at a bit of an angle to the rope, you'll end up deflected in a circle.
Gravity is like you running in the same direction. You can't change the direction of gravity but you can mess with the wall's (or rope's) reaction direction.
Ski down the slope. Throw the skis sideways and the reaction force from the snow will stop you (hockey stop).
Ski down the slope. Put the skis on edge at an angle, so not quite sideways: the reaction force from the snow will deflect you gently into a turn. As gravity keeps pulling you down, you will keep turning until you loose momentum. If you had instead kept running or had rockets strapped to your boots, you'd keep turning up the hill and in a circle.
The more you put the skis on edge (not as the angle to the straight down, but on edge), the reaction force will be stronger, redirecting you faster into a tighter turn.
As you start carving, depending on the snow hardness, you can now put as much as 2-3g into it. The stronger reaction force will interact with the sidecut design and bend the skis into a tighter turn.
Pivoting and steering are like running into a wall of gell-o or tied with a soft rubber band: it will slow you down some, but not quite deflect you. To be deflected across the hill, you need a strong platform, i.e. carving. By pivoting, you'll slow down slowly and change direction of COM slowly. By putting the skis at a sufficient angle to carve, the rate of slowing down (in the "down" direction) is faster and the change in direction (deflecting) is much faster.
The degree of inclination vs angulation is a matter of two things: putting the skis on edge at a sufficient angle for the deflection you want to get and balancing against it while you turn. It also has the benefit of increasing edge hold.
Since the name of the game is "how fast we deflect", the speed at which we establish the serious edge angles matters. I.e. the faster you get on a solid edge, the faster you turn... just ask Ted.
The fore/aft relationship of bos/com is not a static issue, as in looking at a photo. Aim the bos where the com will be, not where the com is.
That's ski physics 101 per razie. I'm sure I missed like a thing or two. Or more.
Edited by razie - 9/15/16 at 5:20pm