science project for holiday

Science Project for the holiday

What you will need:

a plate

full cream milk

food colours

detergent

An improved procedure [source]

1. Pour some full cream milk into a dinner plate

2. Squeeze some drops of food dye into the milk (one colour on one

side, other colour on other side)

3. Add a drop of detergent onto the edge of the plate so it runs

down into the milk

4. The colours begin swirling like a psychadelic pattern

5. You can add more detergent if the motion stops

Explanation [The explanation in the above video is incorrect]

Like milk itself, this classic experiment is actually quite

complicated. Milk is a suspension of tiny fat globules (about 4% by

volume) in water, plus a whole range of proteins, sugar (lactose)

and nutrients like calcium. Detergent is a form of surfactant

(short for surface active agent) - individual detergent molecules

can bind with both water and oil.

The swirling effect in milk is probably driven by the detergent

molecules racing around and coating the fat globules. As the

detergent molecules are "consumed" by the fat, they create

currents. You'll notice colours from the opposite edge of the plate

appearing near the detergent and then shooting across the surface.