Bouncing or rotating?

One possible perception is that the sticks are bouncing off each other, the other is that they're rotating in the opposite directions. (The code reveals the sticks never bounce.)

Ooooooh very optical illusion-ey!!! No matter how many times I read the explanation or the code it still looks like the sticks are bouncing to me, haha.

I'm impressed by how strongly the red arrows influence how I see it.

Yes, I really like it.
But I think the red arrows don’t have as much influence. When the center of rotation coincides, I see a bounce (even if it is not) and as it moves, the effect disappears because when it shows what happens between these centers of rotation ... the trap is in sight.

Joan

In the first version of the project there were no red sprites; nevertheless, as soon as two centers of rotation coincided, my mind interpreted the motion as bouncing.

I needed to move the centers apart to see the rotation.

But then I was afraid maybe it is just me seeing the bouncing when there is only rotation, so I added the red arrow to explain to other people what I am seeing.

Now that you people have seen the bouncing, too, I am thinking maybe I should hide the red things.

Yes, this was the purpose. Thanks for finding the words, Joan.

Thanks. I can not 'unsee' the bouncing, either; despite knowing what I did in the code. Funny feeling, indeed; as if mind has its own mind.

M y B r A i N i S s A y I n G o N e T h I n G b U t M y E y E s A r E s A y I n G a N o T h E r .

I spent so long trying to read that. Then I scrolled down and realized I lost 10 mins of my life.

lol