Kitchen Science: Magic Milk

What is the magic ingredient? Soap?

"a few drops of regular dish soap," according to the narrator.

Thanks. Many of these videos are poorly miked. I think soap would negatively affect the flavor and potability of the milk. If I had a houseful of kiddies to feed, I don't think I'd want to be pouring milk down the drain.

Help! We need a physicist to explain this. The soap obviously spreads out at the start, and clears the fat, but why does that cause all the convection?

Hmm, perhaps this explains plate techtonics. One of those early asteroids that hit the earth was a Fairy Liquid bottle.

Bob

The magic ingredient is the soaring musical accompaniment.

Hey. Nice post.

I love finding stuff like this for my kids to do, particularly at this time of year. I followed the link on YouTube and then found this site: http://www.science.tv . By the looks of it, the site only launched a few weeks ago but it seems to be specifically for this kind of content. Here's another one that my five year old twins loved doing http://science.tv/watch/3d06de0ca9a15b615367/How-To-Make-An-Ocean-In-A-…

Happy Christmas

Eric

That's really neat. Can onyone expain how it works? Is the detergent causing the fat to sink, and thus pushing up the rest of the liquid? It looks like the swirls open up within swirls. I'm thinking it's similar to the movement of water in ocean currents.

"Help! We need a physicist to explain this."
Here is how a "natural scientist" explained it intuitively: Colors are made so they mix easily with the food into which they are introduced, and for this, their must be some composite ingredients present in the colors, which facilitate the mixing, but which are normally "cleared" by the action of the soap. So, both propensities of these composites ingredients combined (intrinsic tendensies to mix with the food and extrinsic subjection to be clear by the soap)create the convection???
It's xmas and this is good enough for me.
AG
PS I am not pedant, I am French, and this translation didn't come easy.
The URL is not my URL, but a site nice enough to publish the writing of a "natural scientist."

I believe this occurs because the soap breaks the surface tension of the milk.

A similar trick can be performed with a paper boat and a small chip of soap. the soap is attached to the back of the boat so it is on the surface of the water. the water prefers to bond to the soap then itself thus breaking the surface tension, the soap bonded water drops by virtue of being more dense then the surrounding water and un-bonded water moves into take it's place. In the milk this produces a convection, with the paper boat it pushes the boat forward.

At least this is my understanding of the principles involved here. It's possible in the milk the reaction is altered slightly due to the fat content, but I believe milk is chosen as a medium to provide a white background colour.

cool experiment :)