When there is an active black hole, we tend to focus on the effect it has on the material it is wrapping. It makes sense to do so; the black holes themselves are difficult to probe. But the interaction between the black hole and the material should also have an effect on the black hole; as you gain material, you should also gain in mass.
Such small feedback responses, especially those previously ignored as trivial, are known as subsequent reactions, and scientists have just observed a specific analog of black holes that can be seen in the water swirling through a drain.
This is a detection that could help study phenomena of black holes too subtle for our current instruments, such as Hawking radiation that is believed to emit black holes. This is a theoretical type of black body radiation that, after a very, very long time, would see a black hole completely evaporate, as long as it does not grow at all.
To study cosmic objects in more detail than we can through the great distances of space, reduced or analogous versions can be created in a laboratory. Like, for example, a recent experiment to reproduce the nucleus pressures of the white dwarf.
Black hole analogs are a great way to find out more about these enigmatic objects and different types can help reveal their secrets in various ways.
Fiber optics and Bose-Einstein condensates have been used to learn more about Hawking radiation. But one of the simplest has to do with how black holes feed: the vortex in the draining tub.
The accretion of black holes can be compared to water spinning down a drain. By treating matter as a ripple in a field, water can withstand space-time itself or a field rippling with quantum activity.
Measuring ripple responses as water fades through a eddy drain can have something to say about energy waves disappearing into a black hole.
An analog vortex black hole in the tub. (University of Nottingham)
From these analogues, we have learned much about the effect of black holes on space and the material around them. But with an external water pump holding the bottom of the system constant, it was unclear whether an analog of the black water hole would have the freedom to be able to react to the waves.
This set of experiments is the first time a bath drainage vortex has demonstrated an effect on the black hole itself.
“We have shown that analog black holes, like their gravitational counterparts, are intrinsic reaction systems,” said physicist Sam Patrick of the University of Nottingham in the UK.
“We have shown that waves moving in a drainage bath push water into the plug hole, significantly altering the drainage velocity and, consequently, changing the effective gravitational pull of the analog black hole.”
When the waves were sent into the system towards the drain, they pushed additional water, accelerating the accretion process so significantly that the water levels in the tub dropped markedly, even while a pump maintained the same level of water. water entering.
This change in water level corresponds to a change in the properties of the black hole, the researchers said.
This could be extremely useful information, in part because an increase in mass changes the gravitational force of a black hole: it changes the way the black hole deforms its surrounding space-time, as well as the effect that the hole has. black has on the accretion disk. In addition, it offers a new way to study how waves can affect black hole dynamics.
“What really caught my eye is that the backlash is big enough to make the height of the water throughout the system drop so much that it can be seen by eye! It was really unexpected,” he said. Patrick.
“Our study paves the way for experimental probing of the interactions between waves and the space-time they traverse. For example, this type of interaction will be crucial in investigating the evaporation of the black hole in the laboratory.”
The team’s research has been published in Physical review letters.