It's kind of strange things, but without magic or juggling: Physicists have turned reality upside down, by making small boats float under a high liquid, and when you see it in the process you might think you're watching some kind of science fiction movie, but it's all about the forces of vibration. Vertical.
Vertical vibrations
It has already been shown that carefully calibrated vertical vibration can keep the liquid suspended in a container, and here the team took advantage of this phenomenon.
"When placed over a less dense medium, the liquid layer usually collapses to the bottom if it exceeds a certain size," the researchers wrote in their paper, published in Nature on September 2, 2010. "Gravity acting on the lower fluid interface leads to a destabilizing effect called insufficiency." Rayleigh-Taylor Instability.
As stated in the report published on the Science Alert website about the study, "Among the many methods that have been developed to prevent liquid falling, vertical vibration has proven its effectiveness, and thus has been studied in detail."
"We theoretically expect and experimentally show that vertical vibration also creates stable buoyancy positions on the bottom face of the liquid, which behave as if the force of gravity is upside down, and thus objects can float upside down on the lower face of the raised liquid layers."
What actually happens here is that the boat (or any similar object as long as it is small enough) gets pushed into the liquid due to the high pressure of the air pocket underneath, which is the pressure produced by the weight of the liquid layer in the first place.
Balance of power
When the upward force of this pressure is balanced with the downward force of gravity, the object floats on the inverted surface downward, and balancing this pressure is the difficult part, and this is one of the main topics in this new study, and the necessary forces were designed mathematically before being tested in the laboratory.
The strange effect remains constant if the boat is pushed or pulled (in this case by the magnet used through the container glass), as it will regain its equilibrium, just as it was swaying on a lake.
The strength and frequency of the vibration are crucial to doing this trick, and as the vibrations decrease the magic spell is broken, and both the boat and the suspended liquid layer descend to the bottom of the room.
This is not just a clever trick for parties, as the results can have a variety of applications, such as transporting gas or other materials via liquids in industrial machines, for example.
And in the meantime, it's cool to see how magical physics can look like.