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Bizarre 'dark fluid' with negative mass could dominate the universe – what my research suggests
It's embarrassing, but astrophysicists are the first to admit it. Our best theoretical model can only explain 5% of the universe. The remaining 95% is famously made up almost entirely of invisible, unknown material dubbed dark energy and dark matter. So even though there are a billion trillion stars in the observable universe, they are actually extremely rare.
The two mysterious dark substances can only be inferred from gravitational effects. Dark matter may be an invisible material, but it exerts a gravitational force on surrounding matter that we can measure. Dark energy is a repulsive force that makes the universe expand at an accelerating rate. The two have always been treated as separate phenomena. But my new study, published in Astronomy and Astrophysics, suggests they may both be part of the same strange concept – a single, unified "dark fluid" of negative masses.
Negative masses are a hypothetical form of matter that would have a type of negative gravity – repelling all other material around them. Unlike familiar positive mass matter, if a negative mass was pushed, it would accelerate towards you rather than away from you.
[...] My model shows that the surrounding repulsive force from dark fluid can also hold a galaxy together. The gravity from the positive mass galaxy attracts negative masses from all directions, and as the negative mass fluid comes nearer to the galaxy it in turn exerts a stronger repulsive force onto the galaxy that allows it to spin at higher speeds without flying apart. It therefore appears that a simple minus sign may solve one of the longest standing problems in physics.
(Score: 2) by acid andy on Thursday December 06 2018, @09:47PM (2 children)
I'm trying to imagine this. If you push against it, you're already extremely close to it, so if it accelerates towards you, does that mean it's pushing back against your hand harder than the normal equal and opposite reaction (probably double)? Or would it just pass right through your hand and head off into the distance behind you?
If a cat has kittens, does a rat have rittens, a bat bittens and a mat mittens?
(Score: 2) by DannyB on Thursday December 06 2018, @10:53PM
It seems like if it repels, then something that starts to push it causes it to move in the direction of push before physical contact is made.
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(Score: 3, Informative) by Immerman on Thursday December 06 2018, @11:09PM
The trick is that there's no such thing as contact forces - everything is actually energy fields pushing against each other, so you can always get closer, until the energy fields balance out.
More generally, think about what happens when you push on something normally - you accelerate away from it, and it accelerates away from you, so it's rapidly out of reach and the pushing stops. If you push on a negative mass though, what happens is you accelerate away from it, and it accelerates towards you, so you remain in contact indefinitely. At least assuming you're the same absolute mass. If its absolute mass is lower than yours then you will accelerate away, while it accelerates towards you even faster, pushing on you harder, causing you both to accelerate faster, in an ever-accelerating spiral that's unlikely to end well.
Fortunately in this case they're proposing it as an alternative for dark matter, which likely means it doesn't interact with normal matter except through gravity, and can pass right through you without interacting.