Triangle

Before square takes its shape, grain creates a little different phenomenom:

Another shape, we will call it the triangle.

The triangle! How is this possible? Well, this is due to the ancient enemy of ”living” flour, gravity. And how actually grain move in the triangle? There are two possibilities. It can be “broken” square, the upper side shrinks almost into single point in the center of the trap, where grain stand still for a while. A evidence of this you can see in the picture above or in the following seven times slower video. Note, that at the top of the triangle, the grain remains for relatively long time.

Second case could be “unfinished” triangle. The grain runs towards the upper vertex and then returns back along the same “path”. See in the following picture the third from right or in the middle.

“Unfinished” triangle.

Most triangles are doing quite well on the ends of the trap. Create them in the middle of the trap is quite challenging, especially, when the grain can not decide in which direction it should rotates. Have a look for yourself, two indecisive triangles on the following seven times slower video.

And one question for you: How long it takes to the grain to create the triangle? Please write your answers in the comments below.