OOBLECK PLATFORM

What is an Oobleck Platform?  A few weeks ago, I wrote about a Pegboard Platform.    Whereas the Pegboard Platform handles a dry medium like sand, the Oobleck Platform is built to handle a wet medium like water, or in this case, oobleck.  Oobleck is a mixture of cornstarch and water and is considered a colloidal solution with dual properties of a solid and a liquid.

The top is a sheet of 1/8" black plastic that I bought in the window section of a large hardware store.  (The technical term for it is HDPE or high-density polyethylene.  In lay terms, it is #2 plastic.)  It is easy to cut with a utility knife and a straight edge.  The frame is 3/4" pvc pipe with 3/4" fittings.  There are eight elbow fittings and ten T fittings in all.  I also got those at the same hardware store.  To secure the platform to the table, I use a 1" x 2" strip of wood that spans the width of the table.  The strip of wood is duct taped to the each side of the table and the frame of the platform is taped to the strip of wood.

Holes are drilled in the four corners to attach the sheet of plastic to the frame using 3/4" multiple-materials screws.  Attaching the sheet on the four corners was more than adequate.  Rows of holes are drilled in an array similar to that of the pegboard platform.  A pipe is fitted in the middle of the top of the frame to give the sheet load-bearing strength down the middle.  

Children do not need an apparatus to explore oobleck.  Oobleck fascinates in its own right.

Introducing the platform, though, adds another level on which to work.  (See dimension #2 and axiom #3 in the right-hand column of this blog.)

It provides an additional level onto which the children drop the oobleck or onto which they set their bowls and such for hands-free pouring or mixing.

It also offers another type of surface to work on, a surface that is flat and will not let the oobleck pool.  In the bottom of the sensory table, the oobleck pools and, because of its solid-leaning nature, is hard to scoop or scrape.  The flat surface allows children to more easily scrape the oobleck with tools.  Watch as the three boys use their shovels to scrape the oobleck from the platform.

Scraping the Oobleck from Thomas Bedard on Vimeo

At the end of the video, the boy on the right says: "I think this is the grossest thing in the whole world." Notice that he is staying clean.  He can stay clean in part because of the flat, elevated surface.

For those who want to explore the oobleck with their hands, the flat surface allows them to easily feel and scrape with their fingers.  Again that is not as easy when it pools in the bottom of the table.  It becomes too thick and takes a lot of effort to handle.  Watch these set of hands fondle the oobleck while  engaging in some free association about how it is like milk.

Caressing the Oobleck from Thomas Bedard on Vimeo.

 
At the end of the video, the hands in the foreground have stopped scraping the oobleck and begin to caress the hard, smooth surface of the oobleck.  The child goes from scraping to caressing in part because of the flat, elevated surface.

Aren't you wondering what is going on under the platform?  I personally thought the sand filtering through the holes of the Pegboard Platform was cool.  I think what happens as the oobleck pushes through the holes of the Oobleck Platform is wondrous.  Watch and you decide.

Oobleck Platform-Underneath from Thomas Bedard on Vimeo.

Let's take a closer look underneath to what is happening. The oobleck is being squeezed through the holes by gravity pulling on its mass.  But do you see the droplets that form at the ends of the streams of oobleck. Why is that?

I do not know why those droplets form.  I do not know why the oobleck flows at the rate it does.  I do not know why some streams reach the bottom of the table and others do not.  There is one thing I do know: it is a wonder to play with, to feel and to behold.