An Extrospective Journal.
Scientists find ‘black holes’ at sea: The ocean whirlpools from which nothing can ever escape – not even water
* Eddies are so tightly surrounded by water paths that nothing can escape
* Scientists have found they are mathematically equivalent to black holes
* The findings may help explain the spread of pollution in the world’s oceans
* It could also help better determine how eddies effect ocean temperatures
They are impossible to see, but astronomers are convinced they exist. Black holes are tears in the fabric of space-time that pull in everything that comes too close to them. Nothing that gets sucked in can escape, not even light. Now, scientists believe they have found features of these black holes here on Earth, in the southern Atlantic Ocean. Some of the largest ocean eddies in this region are mathematically equivalent to the mysterious black holes of space, according to researchers from ETH Zurich and the University of Miami.
This means that they do the same thing with water, that black holes do with light. These huge ocean whirlpools are so tightly surrounded by circular water paths that nothing caught up in them escapes.Their numbers are reportedly on the rise in the Southern Ocean, increasing the northward transport of warm and salty water.
Scientists believe these ocean eddies could moderate the negative impact of melting sea ice in a warming climate. But up until now they’ve been unable to quantify this impact because the exact boundaries of these swirling water bodies have remained a mystery.
George Haller, professor of Nonlinear Dynamics at ETH Zurich, and Francisco Beron-Vera, research Professor of Oceanography at the University of Miami, believe they have now solved this puzzle. Using mathematical models, they isolated water-transporting eddies from a sequence of satellite observations. They did this by detecting their rotating edges, which the scientists found were indicators of the whirlpool within.
To their surprise, these eddies turned out to be mathematically equivalent to black holes. At a critical distance, a light beam no longer spirals into the black hole. Instead, it dramatically bends and comes back to its original position, forming a circular orbit.
A barrier surface formed by closed light orbits is called a ‘photon sphere’ in Einstein’s theory of relativity. The researchers discovered similar closed barriers around select ocean eddies.
In these barriers, fluid particles move around in closed loops – similar to the path of light in a photon sphere. And as in a black hole, nothing can escape from the inside of these loops, not even water. The researchers identified seven Agulhas Rings of the black-hole type, which transported the same body of water without leaking for almost a year.
‘Mathematicians have been trying to understand such peculiarly coherent vortices in turbulent flows for a very long time’, explained Haller.
Their results are expected to help in resolving a number of oceanic puzzles, ranging from climate-related questions to the spread of environmental pollution patterns.