Physicists create liquid with 'negative mass'

American scientists have created a liquid with negative mass. When you push on this liquid, it accelerates backwards instead of moving forward.

The first matter with negative mass has been created in the lab in liquid form. Photo: iStock.

Scientists at the University of Washington, USA, have successfully created a liquid of super-cold atoms that acts like it has negative mass, according to Science Alert. When you push this liquid, it does not accelerate in the direction it was pushed, but accelerates in the opposite direction. The research results were published in the journal Physical Review Letters.

According to physics, matter can also have negative mass in the same way that electric charge can be either positive or negative. Negative mass exists in the universe without violating general relativity. Many physicists believe that negative mass is related to some strange things in the universe such as dark energy, black holes, and neutron stars.

Isaac Newton's second law of motion is often written as F=ma, where F is the force acting on an object, m is the mass, and a is the acceleration of the object. When we rewrite it as a=F/m, if the object has negative mass, it will have negative acceleration. Imagine pushing a glass cup across a table, but it moves in the opposite direction to your hand.

The team used lasers to cool rubidium atoms to near absolute zero, creating a Bose-Einstein condensate. In this state, the rubidium atoms move very slowly and obey the strange principles of quantum mechanics, not classical physics. They begin to behave like waves, with positions that cannot be precisely determined.

The rubidium atoms synchronized with each other and moved in unison, forming a superfluid that could flow without losing energy to friction. The scientists then used lasers to keep the superfluid at very cold temperatures, trapping it in a bowl-like space smaller than 100 micrometers.

When the rubidium superfluid is in a bowl-like region of space, it has normal mass. The team used a second set of lasers to nudge the rubidium atoms back and forth, changing their spins, breaking the bowl apart, allowing the superfluid to flow out so quickly that it appears to have negative mass.

“Once you push, the fluid accelerates backwards like rubidium hitting an invisible wall,” said Michael Forbes, a member of the research team.

The scientists believe that the liquid they created is indeed a material with negative mass, but it needs to be independently and objectively tested by other research groups in the future.

According to VNE