28-year-old Italian Dario Bonzi from Brescia on December 2, 2018, went on a picnic in the Val Camonica mountain valley in the Central Alps.
When Bonzi went to fetch water from a public water pump, he saw that it was not tightly covered and a trickle of water was flowing from it.
But it was not the wastefulness that struck the Italian, but the water itself, because at first he decided that the jet had frozen and turned into an icicle. And it is not surprising, because nothing seemed to indicate that the water was actively draining from the tap.
It was only when Bonzi raised his fingers to the trickle that he realized that the water was not frozen. But when he removed his fingers, the trickle "froze" again and began to look static.
This optical illusion struck the Italian and he filmed it on video, and then in an interview admitted that he had never seen anything like it before.
Laminar flow or laminar flow is a flow in which a liquid (or gas) moves in layers without mixing and without pulsations. That is, without erratic rapid changes in speed and pressure.
Promotional video:
Bonzi says that for water to flow in a laminar flow, it must be very pure water without impurities. Which, by the way, is a pretty good advertisement for an ordinary water pump.
Also, in order to achieve this effect, the water must flow through a tube with a very smooth surface and at the same time it must not be influenced by the wind. And when all the conditions add up, there is just such an illusion of complete immobility of the jet, although in fact it is moving.