Non- Newtonian Fluid

Make your  gooey glop that is neither a solid nor a liquid.
 Using only cornstarch and water, this amazing mixture behaves like a solid and a liquid at the same time. 

Method

1. Pour approximately 1/4 of the box of cornstarch into the mixing bowl and slowly add about 1/2 cup of water. Stir. Sometimes it is easier to mix the cornstarch and water with your bare hands– of course, this only adds to the fun.
2. Continue adding cornstarch and water in small amounts until you get a mixture that has the consistency of honey. It may take a little work to get the consistency just right, but you will eventually end up mixing one box of cornstarch with roughly 1 to 2 cups of water. Notice that the mixture gets thicker as you add more cornstarch.
3. Notice its unusual consistency when you pour it into the pan. Stir it around with your finger, first slowly and then as fast as you can.
4. Skim your finger across the top of the glop. What do you notice?
5. Sink your entire hand into the glop and try to grab the fluid and pull it up.
6. Try to roll the fluid between your palms to make a ball.
7. You can even hold your hand flat over the top of the solution and slap the liquid glop as hard as you can. If your mixture  splatters everywhere, you will need to add more cornstarch.
8. As you play with the glop,  why does the liquid behave in this manner. What causes it to feel like something solid when you squeeze it, yet flow like syrup as it drips off your finger? When you are finished, pour the glop into a large zipper-lock plastic bag for later use.

How Does It Work?

How does glop act like a solid sometimes and a liquid at other times?

Actually, glop is an example of what is called a Non-Newtonian fluid – a fluid that defies Isaac Newton’s law of viscosity. All fluids have a property known as viscosity. It is the measurable thickness or resistance to flow in a fluid. 

Newton stated that the viscosity of a fluid can be changed only by altering the fluid’s temperature. For example, motor oil or honey flows more easily when you warm it up and becomes very thick when it gets cold. So, a Non-Newtonian fluid has the same dependence on temperature, but its viscosity can be changed by applying pressure. 

Ironically, the cornstarch will not stay mixed with the water indefinitely. Over time, the grains of cornstarch will separate from the water and form a solid clump at the bottom of the plastic storage bag. It is for this reason that you must not pour this mixture down the drain. It will clog the pipes and stop up the drain. Pour the mixture into a zipper-lock bag and dispose of it in the garbage.