> Yep, that is a very interesting mixture! If anyone wants to do more 
> research
> about it, this is often called "oblick"; though there are many 
> similar
> spellings. Looking up "non-newtonian fluid" will result in further
> info. I've recently read that this kink of substance is being looked 
> at to
> create bullet-proof vests that are light and flexable.


        http://en.wikipedia.org/wiki/Non-Newtonian_fluid


I wondered at the time how cornflour would work in bullet proof vests 
:-)
"Bullet proof" vests.


        http://en.wikipedia.org/wiki/Body_armor


Then there's Glurch ... :-)

Oobleck, Glurch, Slime, Silly putty. Enjoy

        http://www.squarewheels.com/content/gackstuff.html

O & G

        http://www.extension.iastate.edu/e-set/science_is_here/glurch.html

        http://www.dctech.com/physics/features/0901.php




__________________

>From 1st ref above:

A non-Newtonian fluid is a fluid in which the viscosity changes with 
the applied strain rate. As a result, non-Newtonian fluids may not 
have a well-defined viscosity.

Although the concept of viscosity is commonly used to characterize a 
material, it can be inadequate to describe the mechanical behavior of 
a substance, particularly non-Newtonian fluids. They are best studied 
through several other rheological properties which relate the 
relations between the stress and strain tensors under many different 
flow conditions, such as oscillatory shear, or extensional flow which 
are measured using different devices or rheometers. The rheological 
properties are better studied using tensor-valued constitutive 
equations, which are common in the field of continuum mechanics.



And:

An inexpensive, non-toxic sample of a non-Newtonian fluid sometimes 
known as oobleck can be made very easily by adding corn starch 
(cornflour) to a cup of water. Add the starch in small portions and 
stir it in slowly. When the suspension nears the critical 
concentration - becoming like single cream (light cream) in 
consistency - the so called "shear thickening" property of this 
non-Newtonian fluid becomes apparent. The application of force - for 
example by stabbing the surface with a finger, or rapidly inverting 
the container holding it - leads to the fluid behaving like a solid 
rather than a liquid. More gentle treatment, such as slowly inserting 
a spoon, will leave it in its liquid state. Trying to jerk the spoon 
back out again, however, will trigger the return of the temporary 
solid state. A person moving quickly and/or applying sufficient force 
with his feet can literally walk across such a liquid.

Shear thickening fluids of this sort are being researched for bullet 
resistant body armor, useful for their ability to absorb the energy of 
a high velocity projectile impact but remain soft and flexible while 
worn.

A familiar example of the opposite, a shear-thinning fluid, is paint: 
one wants the paint to flow readily off the brush when it is being 
applied to the surface being painted, but not to drip excessively.

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