concentric circles of water

The circles are merely waves propagating outward from the centre. Similar to the propagation of sound waves.

They do not rotate.

They may not be exactly concentric. It may be influenced by the direction the stone were traveling or the shape.

I am not now sure of this. (it has been a long time since I played hopping stones)

what is the direction of rotation of circles clockwise or anticlockwise

Neither, it's up and down and away from the original point source of the disturbance (the stone).

http://en.wikipedia.org/wiki/Wave_propagation

This has got 'try this at your nearest pond' experiment written all over it.

Do the experiment. Try, don't ponder.

A corollary of this (I think that's the right term ) when water fowl; duck, goose or swan, move at a constant speed from some point on a still pond a V like chevron of ripples are formed. This is actually the same phenomena but from a moving source. What makes the original question a collection of concentric rings is that the source of the perturbation does not move.

manoips,

Prior to the piercing fall of the stone into water, there existed a stable status of the open water body. The fluid volume being flexible, there exists a constant tumbling action, the up and down ward shaking of water/ fluid. This is supported by complex air flow and atmospheric pressure variations leading to ripples.

When a stone is thrown into a water, it peels a circular hole along with air and the stone keeps going down. The sudden pressure difference caused by piercing stone and air , creates turbulence and the fluid instantly collapse to fill the gap. This initiates the concentric ripples propagation and the reverse air bubble also adds to the tumbling action, and gets gradually vanished after some time.

If the stone is thrown by a spiralling action, in that case possible directional clock or anti clock are possible.

"Big whirls have bigger whirls

That feed upon velocity

Smaller whirls have smaller whirls

And so-on, till viscosity"

- Anon.

Look at wave propagation (simple). This should tell you all you want to know.

The question isn't mysterious but the reason for the question may be.

Hello manjps,

I have not looked at any reference to this answer, or I should say 'correct' reply . But, think about it; first you have a stone hitting the surface of the water, that causes a wave/s to propagate.

The stone sinks and the water rushes in to take the place of the hole the stone made, and it will make a drop or several drops of water go directly up from the impact site of the stone. This drop makes yet more much smaller waves or ripple as it lands.

If the water is flat calm the surface tension of the water prevents too many more splashes or waves, but if the stone was large enough, you would indeed get several of these sequences, and will a larger stone a consequently larger 'hole is made in the water and a whole lot more waves caused by the splashes.

I am not sure what you mean when you ask which way do the waves or ripple go round. It kind of happens too fast to notice, but you may be referring to the spin of the earth having some effect on the ripples? I do not think they do have an effect. However, it would be nice to here from someone who has worked on this type of thing and get them to explain how you could go about 'measuring' whether the wave goes out and round, or just out from the impact and then reflects back off the bank or other object like a boat and covers the splash area.

Interesting question, and one you can test to some extent by your own actions.

You could video it and count how many waves are propagated from a simple direct drop of a stone, and if there would be more waves if the stone was thrown from the bank?

Take care.