Light has been made into a fluid that simulates space-time

By manipulating light in a fluid form, then using it to simulate space-time, the researchers hope to unlock our understanding of black holes and other exotic objects.

Supermassive cosmic objects, such as black holes, are very difficult to study directly, but researchers can build useful analogues in laboratory using quantum effects. For example, researchers previously simulated space -time – the fabric of our physical reality – using extremely cold atoms, then populated it with the equivalents of black holes.

Now, Kévin Falque at the Kastler-Brossel Laboratory (LKB) in Paris and his colleagues have used light to create an exceptionally well controlled space analog.

To do this, they confined light in a small cavity made from a reflective semiconductor material, where it bounced between the layers of the material and interacted with the electrical loads inside. During this process, quantum interactions ultimately transformed light into a liquid type of matter.

The team could use lasers to control the properties of this fluid and sculpt it to have the same geometry as space-time. They could also handle it to create structures equivalent to the horizon of a black hole – the edge whose objects can fall but will never return.

Because their “universe” based on light could be very well controlled, Falque and his colleagues could create not only event horizons, but also similar space-time structures which are less steep.

They hope to use this unique simulation to test how Hawking Radiation, which emanates from the black holes, changes with the slope of the horizon of the event. To get there, however, they will have to make their experience colder and more isolated, which will increase the quantum effects within it.

“Work is an impressive experimental strength,” said Juan Ramón Muñoz de Nova at the Complenese University in Madrid, which was involved in the first measure of Hawking radiation in a black hole simulation using ultra -color atoms. He says that the new experience opens the door to the observations of a variety of new phenomena, including the way black holes vibrate or “ring”.

Friedrich Koenig at St Andrews University in the United Kingdom says that new work has demonstrated “a most useful platform”. It could test new ideas on gravity, as well as the mysterious interaction between gravitational effects and quantum effects.

One of the most extreme results of this experience could be that we discover that certain black holes observed are in fact impostors, explains Maxime Jacquet, also in LKB. The first image of a black hole, taken by the Horizon Event telescope, certainly resembles the real thing – but looking like a black hole is not the same thing as being one, he says.

Could there be massive objects that fold the light like black holes, so look like them in the images, but which have no horizons of events? Theoretical work has shown that this is possible, but light -based experiences can be able to explore this possibility more, explains Jacquet.

“We must be very careful. Even if we have these analogues – there is a liquid and there is a black hole – these objects are super different, ”explains Falque. “But what we do in this experience is to test and play with the theory that is used for black holes.”