China News Service, Beijing, September 3 (Reporter Sun Zifa) The internationally renowned academic journal "Nature" recently published a physics research paper saying that scientists have reported a mini-ship floating in the opposite direction under the suspended liquid layer, showing a subversion of tradition Unusual buoyancy that recognizes and challenges Archimedes' law.
Under the action of gravity, the liquid in the container (such as a flask) usually falls to the bottom of the container.
But under certain circumstances, the vertical vibration of the liquid can make it float on a low-density layer (such as an air layer).
The corresponding author of the paper is Emmanuel Fort (Emmanuel Fort) of the Ecole des Physics and Chemical Engineering, Paris University of Arts and Sciences, French National Research Center, Langevin Institute, and his colleagues found that this This kind of vertical vibration can also reverse the buoyancy in the lower layer of the suspended liquid-as if gravity reversed. In the experiment, they injected liquids such as silicone oil or glycerin into the container, and then vibrated the container vertically and injected air into the bottom of the container until the liquid began to suspend. , Objects like model boats can float in the opposite direction on the lower surface of the suspended liquid.
The author of the paper explained that vertical vibration caused this obvious anti-gravity effect.
Not only that, they also found that the air bubbles under the liquid sink rather than rise, which is a related antigravity effect that has been observed in previous experiments.
This "reverse buoyancy" experimental observation challenges people's intuitive understanding of the liquid-air interface, and may help to further study the behavior of liquid boundaries in the future.
"Nature" published a peer expert opinion article at the same time and pointed out that the observation results of the research paper violated Archimedes' principle, that is, an object immersed in a fluid receives a vertical upward buoyancy force equal to the gravity of the fluid expelled by the object.
Its research shows that this buoyancy will be mapped to the lower interface of the suspended liquid layer, and this is proved by using two boats floating on the upper and lower layers of the suspended liquid layer at the same time.
However, this is not just a maritime spectacle. This phenomenon may have practical applications in transporting materials trapped in gases or fluids.
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