Sep 09, 2020 08:00:00

A mysterious phenomenon of floating upside down yachts in floating liquid is announced

Archimedes' principle is the law that 'an object that enters a fluid gains an upward buoyancy equal to the weight of the fluid it displaces.' However, contrary to this law, a paper reporting that it was possible to cause the phenomenon that ``unusual buoyancy occurs and the yacht floats upside down'' was published on September 2, 2020 ..

Floating under a levitating liquid | Nature
https://www.nature.com/articles/s41586-020-2643-8

Vibration overcomes gravity on a levitating fluid
https://www.nature.com/articles/d41586-020-02451-w

Up Is Down in This Fun Physics Experiment-The New York Times
https://www.nytimes.com/2020/09/03/science/floating-upside-down-liquid.html

Even if you slowly pour water over the oil in the aquarium, the balance will be lost a little and the water that is denser than the oil will sink under the oil. However, if certain conditions are met, it is possible to suspend a liquid layer on a layer of low density material such as air.

The research team of Emmanuel Fort et al. of the Polytechnic University of Paris, who published the paper this time, has developed a research that was further developed from the past knowledge that 'it is possible to float a liquid by applying vertical vibration'. To do so, we conducted an experiment in which silicon oil or glycerol, which has a higher viscosity than water, is vibrated.

When you play the movie of the following academic journal Nature, you can see how the liquid actually floats.

The weird physics of upside down buoyancy-YouTube


More liquid floats above the layer of air above the liquid.

This phenomenon is caused by the intense pitching of the aquarium.

If you put a viscous liquid in an aquarium that can be turned upside down like an hourglass and then turn it over ...

The liquid will drip from top to bottom according to gravity.

Normally, you can observe how the liquid is pulled by gravity and forms and drops like this.

So, when I turned over the aquarium with proper vibration, some of them kept dripping and stayed in the upper part. This is because the vibration prevented the formation of water droplets.

This phenomenon itself was discovered in the past, but the research team of Fort et al. tried putting a plastic boat in the aquarium this time. Then, using the magnet attached to the boat, attach the bottom of the boat to the layer of water floating in the air...

The boat floated upside down.

This study has revealed that the lower part of the liquid layer floating in the air overturns the common sense that 'objects float upward'. Dr. Vladislav Sorokin and his colleagues at the University of Auckland, in a contribution to the journal Nature, said, 'This discovery is not just a rare phenomenon, it could be applied to the transport of gases and objects trapped in fluids.' He said.