1Two things to know first
It's just grains sitting in water
The goo is two things mixed up. Watch each one:
Tons of tiny grains
Cornstarch is a powder made of zillions of tiny grains, packed almost shoulder to shoulder.
Thin water in the gaps
Between the grains is a little water. It works like slippery juice that lets grains slide past each other.
2It depends how fast you push
Same goo — two ways to push it
Push slow 🐢
The grains have time to shuffle out of the way. Water sneaks into the gaps and they slide past each other. It feels runny.
Push fast 💥
No time to shuffle! The grains slam together and there's no room left. Keep this in mind…
3Watch the grains up close
Slide the speed and zoom in on the grains
This is a zoomed-in window into the goo. Drag the speed slider and watch what the grains do: do they slide past each other, or jam shoulder to shoulder?
Slow: grains drift apart, water flows through, the goo runs like liquid. Fast: grains jam shoulder to shoulder and lock up like a solid.
4Now predict the two pushes
One fist, two speeds — what happens? 🥊
Here's a tub of the goo. We'll do the same thing twice in the same spot: a fast PUNCH, then a slow PRESS. The only thing that changes is the speed.
Guess before you poke
You punch the goo fast, then push a finger in slowly. What happens each time?