Negative mass was something physicists never thought they would find – let alone create. For more than a century, physics has operated on the foundation that mass is always positive. From Newton’s laws to Einstein’s theories, the idea has been non-negotiable: mass resists acceleration, pulls objects toward the Earth, and anchors the universe in predictable motion. Entire branches of science and engineering are built on this unshakable principle. Now, this might change with the discovery scientists made.
Negative mass is coming: What does this mean for science?
Laboratories around the world have been looking for new ways to make use of the laws of physics. New technologies like ultracold atomic condensates, semiconductors, or light-matter microgravities are changing the way scientists do business and look for negative mass. Until now, it was only a theory – like most things in our universe. On the other hand, they might have found a solution to this matter.
Changing the way mass is interpreted can cause serious implications and rip through our current understanding of gravity, propulsion, and the current structure of the cosmos. In a new experiment in which researchers put a cloud of atoms near absolute zero and changed the usual rules of motion, they found something that could challenge the existence of negative mass.
Researchers put the theory to the test: It responded in a way they didn’t think it would
Washington State University researchers have taken a step that once belonged only in theory: they built a fluid that behaves as if it has negative mass. In practice, that means the rules flip. Push it one way, and instead of moving forward, the fluid rushes back toward the force.
The team cooled rubidium atoms to nearly absolute zero, creating what’s called a Bose-Einstein condensate – a state of matter where particles move in unison and act like a single wave. By trapping the atoms with lasers and then adjusting their spin with a second set of beams, the scientists were able to force the condensate into a condition where its behavior mimicked the exotic mass.
If you can prove its existence, build and prove it: The outcomes would impact physics like nothing before
One of the researchers, Michael Forbes, explained that under these circumstances, the atoms appeared to rebound as if striking an unseen barrier. This method gives physicists more control than previous attempts, which often came with side effects that clouded the results.
According to Forbes and his colleague Peter Engels, the approach could help scientists model extreme environments — from neutron stars to black holes – where testing in real life is impossible. Their work, published in Physical Review Letters, shows that negative mass can be more than just a theoretical curiosity; it can be engineered in the lab.
Scientists have long tried to create something in the lab that’s extreme, but mostly theoretical. Take gravity, for example. It’s the principle of almost anything massive in the universe. Einstein’s theory points out that if a massive stellar body causes a bend in space-time, gravity would take on the responsibility to draw everything around to the center of the formation, like our Sun does with the solar system, keeping everything in place.
The meaning of the discovery goes deeper than finding something new about the universe
Finding a negative mass would mean gravity, one of the reigning forces in the universe, can be tricked. Opposite mass means it doesn’t obey the laws of physics, because once you try to make it go forward, it would speed backward. This would put general relativity and quantum theories to the test to a point where it’s most likely to be proved right rather than wrong – it puts limits to Einstein’s equations.