14 DAY TRIAL // For the first time ever, a group of scientists has demonstrated experimentally that it is possible to produce a white hole inside a simple kitchen sink. The idea has been hypothesized a long time ago.
At this point, there are numerous difficult-to-tackle issues in physics, one of which is the problem of hydraulic jumps. The phenomenon can be observed in the average household.
When tap water flows in the kitchen sink, it hits the surface, and then spreads out in a circular pattern. As this happens, the edge of the water front is made of a circular, lip-like structure.
This formation, called a hydraulic jump, has fascinated physicists for many years because it is very difficult to explain why is it that water height changes so drastically there.
Over the past few years, interest in this issue has spiked. Astrophysicists explained at one point that the phenomenon may be connected to white holes, theoretical cosmic bodies that are the exact opposite of black holes.
Additionally, the hydraulics problem has fascinated experts for about a century, with the first work in the field published by scientist John Strutt in 1914.
In more recent times, theoretical physicists have conjectured that hydraulic jumps are examples of white holes, the exotic structures that do not allow light or matter in.
Whereas black holes trap everything, and do not allow for matter or light to escape, a white hole emits light and matter, but cannot allow either to penetrate it from the outside.
Even if theories of this have been published in respected journals, no one has been able to prove the connection experimentally until now.
But a team of French researchers from the Université de Nice Sophia Antipolis managed to do just that, under the directions of expert Gil Jannes, Technology Review reports.
In principle, a white hole could develop in the average sink if the flow at the edge of the water front is traveling faster than waves can travel.
If this condition is met, then there is no way for the water waves to reenter the front against the flow. But proving this experimentally proved to be a lot more complex than originally thought.
The French team however took a simple approach, and derived all the measurements of water flow and speed they needed by analyzing the Mach cone of the flowing water.
The Mach cone is the v-shaped flow that is left behind if you place your finger inside flowing water.
“We provide an experimental demonstration that the circular hydraulic jump represents a hydrodynamic white hole,” the team says, in a paper appearing the online journal arXiv (.pdf).