Whip-like motion in the luminous pattern produced by the ferrofluid film

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Whip-like motion in the luminous pattern produced by the ferrofluid film, we are Adriana and Alberto Tufaile.
We have already made an analogy of jumping sundogs using ferrofluid films in the article “Jumping Sundogs, Cat’s Eye and Ferrofluids”, Condensed Matter, 2020.
Now we are analyzing the details of the whip-like motion that occurs in the sky, reproducing this type of movement in the luminous pattern produced by the ferrofluid film.
With laser illumination and by moving a magnet close to the ferrofluid film, we can move the diffraction pattern of the light.
In a ferrofluid film, as in an illuminated Ferrocell, the luminous pattern can undergo a whip-like movement when we change the orientation of the applied dipolar magnetic field.
To display the experimental setup, at the end there is a reproduction of our video Horocycles of Light.
Here we can see in slow motion the whip-like movement.
Pay attention as the horocycle breaks and one end makes a whip-like movement.
This image sequence depicts this process for the case of the initial horocycle pattern, in which a horocycle forms due to a stronger magnetic pole positioned near the ferrofluid plate. At number 2, we have the disruption of the Horocycle, because as the field changes slightly, this change disrupts the initial horocycle pattern. At number 3 and 4, we have a transition to open curve, because with both poles affecting the ferrofluid equally, the pattern transforms into an open curve shape. The diagram illustrates the sequence of light patterns observed during the process. The key to the whip-like motion lies in the green curve marked "2". This unstable pattern represents a sudden transition, similar to shifting from a single potential well (area of attraction) to a double well potential, where the ferrofluid experiences two competing forces. This abrupt change is what causes the whiplash movement.