Scientists have turned the world upside down with a strange tendency in physics that allowed them to float toy boats the wrong way under a body of liquid.

In a stunning display of the mind-bending effect, boats appear to defy the laws of gravity as they tumble on the water above them with their sails pointed down.

This strange phenomenon is a great trick, but researchers say the discovery could have practical implications, from processing minerals to separating waste and pollutants from water and other liquids.

“We were playing,” said Emmanuel Fort, a researcher on the team who discovered the impact at the Graduate School of Industry. Physics And chemistry in Paris. “We had no idea it would work.”

Scientists made their discovery while studying the strange effect that vibrations can have on the behavior of fluids. Researchers already knew that, given the right kind of vibrations, bubbles could sink into liquids, while the heavier particles that would normally settle float to the surface instead.

Another strange effect of the vibrations is that it allows a layer of liquid to float in the air, provided it is in a closed container. The explanation lies in the ability of the vibrations to stabilize unstable systems.

If a container containing a liquid liquid is quickly turned over, the liquid will drop to the bottom. But the liquid does not fall off all at once. Instead, drops form first on the underside of the liquid, breaking down the rest of the liquid.

But put the container on a vibrating plate and the liquid can act completely differently. Vertical vibration at the correct frequency prevents droplet formation. Without it, the liquid stays aloft: instead of falling, it anchors an air cushion.

This was already known. What Forte and colleagues showed is that objects can experience an “anti-gravity” effect and float to the underside of the raised fluid. Writing natureThey demonstrated this with tiny toy boats floating in raised layers of glycerine and silicone oil.

Several forces keep the boats in place. The first comes from air pressure, which is lifted by the weight of the liquid above, and pushes the boat up into the water. But the liquid rushes back into the same boat, a force that decreases above the layer. Gravity pulls the boat down. All this leads to a delicate balance that could collapse at any moment, were it not for the vibrations.

“If you move the boat down in the air, it will fall, and if you move it up, it will rise to the fore. The whole trick is not just to make it possible in the first place, but to stabilize the balance,” Forte said.

Researchers believe the work opens new avenues for study, and they suspect the effect could be beneficial for industrial processes, such as removing plastic particles from liquids. But for now, scientists are simply enjoying the strange effect.

“The cool thing is that it elicits reactions from people who are not scientific,” Forte said. “People say the scene is like the scene in Pirates of the Caribbean when the boat floats upside down. It doesn’t make sense. It gets people talking about science fiction and fantasy and that’s so nice.”