Researchers have created a fluid with negative mass that exhibits heretofore theorized behavior. This anomalous matter created in lab demonstrates the debated scientific hypothesis of negative mass.
Imagine kicking a ball, and instead of rolling away, it accelerates backward into your foot. If this ball existed, the only explanation for its behavior would be that it has a negative mass.
Lab-Created Fluid With Negative Mass
Led by Peter Engels, professor of physics and astronomy at Washington State University, a research team created a fluid exhibiting behavior of our stubborn soccer ball. The fluid has a negative mass that, when pushed, doesn’t accelerate in the direction of the force applied. Instead, it lunges back at the direction of the force.
In the study, Negative-Mass Hydrodynamics in a Spin-Orbit–coupled Bose-Einstein Condensate, published in the journal Physical Review Letters, physicists described how they had composed this anomalous fluid.
To create conditions for negative mass, they had to cool rubidium atoms close to absolute zero, creating a Bose-Einstein condensate. BECs (named after Satyendra Nath Bose and Albert Einstein who predicted its existence) are a state of matter where particles move slowly, no longer driven by classical physics laws but by quantum mechanics. Particles in this state behave like waves; they synchronize and move in unison, forming a superfluid which flows without losing energy by friction.A WSU research team may have stimulated and observed negative mass. Warp speed ahead!Click To Tweet
This rubidium superfluid still has regular mass. To create negative mass, the researchers applied lasers to kick the atoms back and forth and change the way they spin. When pushed fast enough, the rubidium superfluid behaves as if it has negative mass.
Which, some argue, is just simulating negative mass in a localized and temporary manner.
Why Negative Mass?
According to Isaac Newton‘s Second Law of Motion, (F=ma) a force equals the mass times acceleration. If pushed, any physical object will accelerate in the direction it was pushed. Not all physical objects behave this way. Unlike known physical objects, when pushed, a negative-mass matter, accelerates in the opposite direction.
Numerous researchers have pointed toward the potential existence of the negative mass in the Universe without breaking the laws of physics.
There have also been previous attempts to understand negative mass, but the WSU technique avoids some complications encountered and gives scientists great control over negative mass created. They could design bespoke matters to study specific negative mass behaviors and explore strange cosmological phenomena occurring in the cosmos, such as neutron stars, black holes, and dark energy, and experiment with their properties in the laboratory environment.
Faster Than Light Travel
If you just glanced over the WSU experiment and noticed that negative mass was observed, you might think the natural implication of this technological advance in understanding indicates that faster than light (FTL) travel is closer to becoming possible.
From the Phys.org article that we are using as a primary source for this article, some commenters made great points. Here are a few that caught our eye:
From JongDan: “To me it sounds like a phenomenon related to negative temperature. By applying those lasers, the atoms were confined, which also bounded the energy upwards, and at the same time excited by those lasers. When you pump in more energy than it takes for maximum entropy state, the whole system starts behaving as a negative-temperature system – microstates with higher energy are favoured, as the total energy is too high anyway.
Apply a force – a potential field, and atoms will flow towards higher energy states – towards the direction the force was applied from.”
JongDan keys in on the limitations of this experiment and its conclusion. How would someone argue against this assertion?
From Nkalanaga: “I doubt that this will be enough for a warp drive, as it’s strictly a local, temporary effect. But the fact that negative mass has been observed is a good sign that there may be more practical ways of achieving the same effect.”
As with most of scientific history, we typically start with inefficient examples of new processes and methodologies and work towards improving fundamental principles. Hopefully Nkalanaga is right.
From IronhorseA: “The quantum nature of the system may be generating a negative acceleration rather than a negative mass. Question is how to determine which of the two terms on the right side of the equation is negative.”
In response, from Mimath224: “My thoughts too. Moving in the opposite direction to the one expected MIGHT be ONE of the properties of ‘negative mass’ but what would be the others for a sufficient definition of negative mass.”
Can anyone help IronhorseA out here? How would you determine the negative parts of the equation? And further, regarding the question Mimath224 posed, what are the necessary factors composing negative mass?