Properties
Hypothetical wormhole in space-time
In theoretical physics, a negative mass is a concept about a hypothetical substance whose mass Has the opposite value to the mass of a normal substance (as well as the electric charge is positive and negative). For example, -2 kg. Such a substance, if it existed, would violate one or more energy conditions and exhibit some strange properties. According to some speculative theories, a substance with a negative mass can be used to create wormholes (worm holes) in space-time.
Sounds like an absolute fantasy, but now a group of physicists from the University of Washington, Washington University, OIST University (Okinawa , Japan) and Shanghai University managed to get a substance that exhibits some properties of a hypothetical material with a negative mass. For example, if you push this substance, it will accelerate not in the direction of applying the force, but in the opposite direction. That is, it accelerates in the opposite direction.
To create a substance with negative mass properties, scientists prepared a Bose-Einstein condensate, cooling the rubidium atoms almost to absolute zero. In this state, the particles move extremely slowly, and quantum effects begin to appear at a macroscopic level. That is, in accordance with the principles of quantum mechanics, particles begin to behave like waves. For example, they synchronize with each other and flow through capillaries without friction, that is, without losing energy – the effect of so-called superfluidity.
The conditions for the formation of Bose-Einstein condensate in a volume of less than 0.001 mm³ were created in the laboratory of the University of Washington. The particles were slowed down by the laser and waited until the most energetic of them left the volume, which further cooled the material. At this stage, the supercritical fluid still had a positive mass. If the vessel is damaged, the atoms of rubidium would scatter in different directions, since the central atoms would push out the outer atoms outwards, and those would accelerate in the direction of the application of force.
To create a negative effective mass of physics, another set of lasers that changed the spin Parts of atoms. As the simulation predicts, in some areas of the vessel particles must acquire a negative mass. This is clearly seen from the sharp increase in the density of matter as a function of time in simulations (in the lower diagram).
Figure 1. Anisotropic expansion of Bose-Einstein condensate with different cohesion coefficients. The actual results of the experiment are marked in red, the results of the prediction in the simulation are black
The lower diagram is an enlarged fragment of the middle frame in the bottom row of figure 1.
The lower diagram shows a one-dimensional simulation of the total density as a function of time in a region where dynamic instability first appeared. The dashed lines are divided into three groups of atoms with velocities
