i'm wondering if anyones noticed the tendency for rocks to curve when you throw them. particularly Flat rocks when you throw a balearic type throw. i Kind of want to learn how to do this bu :questiont i'm not having much luck.

I could be wrong. But I think :

1) All peebles revolve around their center of gravity.
2) For all peebles, the path of the center of gravity is right.

And more,

3) A flat peeble behaves like a fin in the air.
4) Aerodynamic peeble behaves like a football (non-amecican) ball with a drived path (Magnus effect).

just my idea.

   Yes, as long as the rocks are spinning they will always curve.  Backspin makes them curve up; frontspin that you get from an underarm throw makes them curve down.  Anything other than a perfect front or backspin and they'll curve to the left or right. 

This video from IronGoober is definitely worth checking out: https://youtu.be/ESrvvBFcrWM.

I don't know if it's entirely applicable because he's slinging a ball, not a flat stone.  But it might introduce some ideas to you.

Any spinning object in flight can experience the Magnus effect. For a flat rock, this effect may be very small. Instead, the curving you are seeing is a result of drag. The stone is taking the path of least resistance. While it is tumbling in flight, that direction changes.

The rounder, the heavier your projectile is, the less the magnus effect will pull it off target. Most important thing is putting rifle-spin onto the projectile if you want to hit things past 30m.
Flat stones curve a lot to the right when you throw them at medium range, but they also release a bit later than rounded ones, so to hit the target, you have to be aware they can cancel each other out to some extent.

joe_meadmaker wrote on Jun 10^th, 2022 at 1:22pm:

This video from IronGoober is definitely worth checking out: https://youtu.be/ESrvvBFcrWM.

Very good video, Irongoober. Clear and educational.  :)
Thanks

If you want to curve rocks choose a less dense rock. Limestone with lots of internal cavities will curve heavily

TOMBELAINE wrote on Jun 13^th, 2022 at 4:43am:

joe_meadmaker wrote on Jun 10th, 2022 at 1:22pm: This video from IronGoober is definitely worth checking out: https://youtu.be/ESrvvBFcrWM. Very good video, Irongoober. Clear and educational.  :) Thanks

Thanks!

Flat, pointy trapezoid rocks will not only bend but actually corkscrew through the air.

I love a good cork screw throw. Not very accurate, but very fun to watch

IronGoober wrote on Jul 13^th, 2022 at 1:59pm:

I love a good cork screw throw. Not very accurate, but very fun to watch

Yeah absolutely. I imagine it would be really hard to dodge too if was coming straight at you. I've seen handgun bullets very visibly do the same thing, which I found rather surprising. I'd like to exactly why it happens sometimes, and why it doesn't other times.

I think it has to do with a precession of the spin axis. Gyroscopes precess, and I would assume a sling bullet/rock  would as well, especially given the forces/torques applied to it as it flies through the air (which will speed up the precession).

It is like a spinning top starting to wobble. I think that is the effect that causes the corkscrew. The precession of the spin axis causes different Magnus force directions/magnitudes so the stone curves, but continuously changing direction.

It’s definitely to do with the Magnus effect and aerodynamics. The precession might magnify the effect even more.