An unusual theory was offered by Italian physics: space-time may be regarded as a superfluid, in which hydrodynamic quantum processes take place.
According to the theories of quantum gravity, space-time is not a continuum but a discrete matrix. On the lower level, space-time is a “quantum foam” of elementary particles sized 10-35 cm.
With such structures physicists are trying to explain the gravitational interaction at the quantum level. To date, there are many theoretical models of quantum gravity. However, none of them can be proved experimentally.
Stefano Liberati of the SISSA school (Scuola Internazionale Superiore di Studi Avanzati) in Trieste, Italy, and Luke Maccione of the Ludwig Maximilian University of Munich, Germany, first proposed a model that provides for the possibility of empirical verification.
According to their theory, space-time at the quantum level behaves like a fluid, the laws of motion of which are determined by the intermolecular interactions.
“If we imagine space-time as a fluid, we will have to take into account its viscosity and other hydrodynamic properties”, said Stefano Liberati.
According to the authors of the model, the fact that the light from the galaxies of stars at a distance of billions of light years comes to us indicates a very low viscosity of the liquid space-time.
Thus, it is a superfluid in which there is almost no friction force. However, even in such a fluid viscosity can be very low, but not equal to zero.
In this case, space-time is still capable of creating a small effect of scattering of elementary particles, which can be detected using very precise astrophysical measurements.
If the Italian physicists manage to do it, they hope that their model of quantum gravity will turn from a theoretical construct into a full-fledged scientific theory confirmed experimentally.