Name: Coriolis Fountain


Coriolis Fountain

Description: A sphere moves around a circular track. It spits out particles radially outward and inward. These particles travel in straight lines, and yet when several particles are viewed at the same time they seem to follow curved tracks. The outward moving particles seem to curve to the right as they move, the inward moving particles also curve to the right.  The outward moving particles fall behind the source, this looks familiar because we see the same behavior in rotating lawn sprinklers. The inward moving ones move ahead of the source, this certainly looks strange. The curved path is the result of the coriolis force. On the exhibit there are several straight radial lines, observe when a particle is launched along one of these lines, it will follow the lines showing that it too is moving along a straight line path.

Creator: Patio Plasma



The coriolis Fountain sign offers a notecard to any person who touches the sign. (See the script below)

Coriolis fountain notecard

Coriolis Fountain

The revolving ball emits particles toward the center and away from the center.

Notice that the particles appear to travel in curved paths.

What's Going On?

Each particle travels in a straight line at a constant speed.

Your perception of the motion of the particles compares the position of each particle with its neighbor and so you see a curved path.
You also see a curved path if you move into the rotating frame of reference of the particle emitter.

In the rotating frame of reference the curvature of the particle path is a result of the coriolis effect.

The particles launched outwards fall behind the rotating wall, the particles launched inwards pull ahead.

Prototype exhibit by Patio Plasma.


The exhibit uses the powerful particle system in second life to generate particles which move radally inward and outward at a constant speed.


Place the notecard into the inventory of the information sign, then put the exact name of the notecard between the quotation marks in the script below.

This script will offer the notecard to the avatar who touches the sign. The avatar is identified by a key number.


touch_start(integer touched)

Comments: There is an exhibit in the Exploratorium Museum that shows this same effect. WE built this exhibit after seeing the original exhibit created by Klas Fresk at Tom Tits Experiment a great science museum in Sodertalje, Sweden.

coriolis fountain exploratorium



Patio Plasma

Copyright 2007

Updated 28 May 2007