Saturday, May 3, 2008

Surface tension.

This is a cool experiment that my dad showed us while he was here.

Get a plate with a lip and fill it with milk. (Water would probably work, but you couldn't see the colors moving as well.) Put three drops of each color of food coloring in the milk.

Put one drop of dishwashing liquid in the center of the plate.

The food coloring zips to the outer edge of the plate, which is pretty fun to watch in and of itself. But the real fun comes a few seconds later. The dishwashing liquid destroys the surface tension of the milk and starts sucking the food coloring underneath and up through the soap drop. Very cool patterns emerge.

If you left it going long enough, the colors would all blend evenly and the milk would turn brown.

1 comment:

free said...

That's too cool! I'm going to introduce this little trick to my son :)
Just found your blog - I'm an unschooler from down-under and never before thought to hunt down blogs about it. Well duh. Glad I have now - will check in every now & then :)