FEROCITY: FLOW IN THE
want some ketchup with your fries, and there you are pounding the end
of the bottle and nothing is happening. You want some honey in your
tea, and its a lot harder to squeeze the bottle now than it was
during the summer.
What we do for
finally achieved the small victory of sweetening your tea, dont
just sip away. Theres science herespecifically, theres
viscosity, which basically means how something flows.
Try putting that
bottle of honey in warm water for a few minutes to change the viscosity.
It will be a lot easier to pour, but once it cools again, it will return
to its hard-to-squeeze state.
same for gold and rock: Heat them enough and they will flow to sometimes
beautiful (and sometimes disastrous) consequences.
exception to this is something you can demonstrate in your kitchen without
too much mess (or a mess that is very easily taken care of).
serving a marvelous mixture of cornstarch and water that I affectionately
refer to as "morph." Ive also heard "glop"
and "ooze," which doesnt quite get it for me. You could
try "non-Newtonian liquid," but thats a bit long and
may make classmates either look at you funny or designate you as the
homework helper. I stick with morph.
For this experiment
1 cup of cornstarch
1/2 cup (approximately) of water
Thick straw (a casing from a ball-point pen works perfectly)
Plastic water bottle
Time (I played with this mixture for longer than I care to admit)
Put the cornstarch
in the bowl and play with it a little while. If you squeeze the powder,
it will sound like crunching snow. So now that your fingers are coated
in powder, start adding water a little at a time (a tablespoon will
do if you are being exact) and mixing with your hands. (Of course, you
could mix with a spoon, but how much fun is that?)
You will notice
immediately that this is not mixing like pancake batter and milkit
doesnt taste like it eitherbut that is the consistency you
want to achieve for perfect morph. You will also experience something
that is not at all common in liquids: If you stir slowly, theres
no particular problem. If you stir quickly, it suddenly feels as if
you are stirring sand.
Try to pick up
some morph. After you finally manage to get some of it in your hands,
try to shape it into a ball. Trust me, it can be done. Then hold it
in the palm of your hand and watch it liquidate. . . all of your hard
work morphing back to its original form! But it felt solid.
perfected the ball, try a cube. It starts caving in before you know
it, but just for a moment it felt as if you could roll for your next
When you finally
tire of doing this, take the thick straw and poke it into the surface
of the morph. What do you think will happen?
If you go slowly,
the straw will go right to the bottom of the bowl. Go quickly, and youll
never hit it. Let your hand sink to the bottom of the bowl and then
pull it out. Again, going slowly is no problem. Go quickly, and youll
pick up the bowl with one finger!
So when youre
finally told its time to do "real" homework instead
of playing with the stuff, dont throw it away! Discover yet another
interesting property of morph by pouring it into a plastic bottle. The
morph will form ribbons on its journey from bowl to bottle.
done with the experiment, just throw away the bottle, and dont
put the mixture down the drain. (Clumps would not be good for the pipes.)
its viscosity when you apply pressure. But not honey, which is changed
by temperature. Of course you could try applying pressure to honeyit
will taste better in your tea, but it wont become morph!