'Dark fluid' with negative mass could dominate the universe
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'Dark fluid' with negative mass could dominate the universe
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Re: 'Dark fluid' with negative mass could dominate the universe
#2Then we are definitely in a simulation. That is the fabric that holds the universe together.
Re: 'Dark fluid' with negative mass could dominate the universe
#3Then we are definitely in a simulation. That is the fabric that holds the universe together.
That's a complete non-sequitur.
Re: 'Dark fluid' with negative mass could dominate the universe
#4>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.
I don't get this, seems contradictory.
Re: 'Dark fluid' with negative mass could dominate the universe
#5Every "dark" physics piece is essentially a science opinion piece, with "darkness" included in the title as the general prevailing clickbait advertising strategy, because the layperson interpretation is that it implies sinister mysteriousness.
It's never news, it's just a refresher listing of unknowns.
Re: 'Dark fluid' with negative mass could dominate the universe
#6>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. I don't get this, seems contradictory.
I was just about to quote that same sentence.
How can positive matter attract negative matter which at the same time is repelling positive matter?
The author is described as an Astrophysicist at Oxford (a reputable place) so I assume I'm either just not getting it or this is poorly worded.
Re: 'Dark fluid' with negative mass could dominate the universe
#7A "dark fluid" with negative mass COULD dominate the Universe, sure.
But so could galactic-scale electric currents and magnetic fields, and is more likely.
No one ever talks about that.
Re: 'Dark fluid' with negative mass could dominate the universe
#8Paper:
https://arxiv.org/pdf/1712.07962.pdf
Not a physicist, but my summary of the author's point would be:
If you allow for matter with a negative mass and plug it into a n-body simulation. You seem to get what looks like dark matter from first principles. Namely, a halo of non interacting matter around galaxies in just the right "non-cuspy" shape. Their conclusion is that this is worth considering, as almost all mainstream cosmology makes the assumption that mass >= 0, despite the fact mass The idea is persuasively simple. Every other force besides gravity is polarised, so why not also gravity? It seems interesting to me, but I'm nowhere near knowledgeable enough to know whether it can be easily refuted.
Re: 'Dark fluid' with negative mass could dominate the universe
#9>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. I don't get this, seems contradictory.
Maybe it was modeled as a curvature of space? So positive masses curve space so that everything moves toward them - including light, massless particles, and negative mass. And negative mass repels everything, including other negative mass, by shaping space differently.
[Edit: jbay808 has a better explanation below, and negative mass attracts negative mass.]
That behavior is described here https://en.wikipedia.org/wiki/Negative_mass#Runaway_motion but it's not what I was expecting either.
Re: 'Dark fluid' with negative mass could dominate the universe
#10Paper: https://arxiv.org/pdf/1712.07962.pdf Not a physicist, but my summary of the author's point would be: If you allow for matter with a negative mass and plug it into a n-body simulation. You seem to get what looks like dark matter from first principles. Namely, a halo of non interacting matter around galaxies in just the right "non-cuspy" shape. Their conclusion is that this is worth considering, as almost all ma…
Is it true that every other forces besides gravity is polarised? There's a repulsive nuclear strong force and an attractive nuclear weak force?
EDIT: Partial answer is that there is a three-"color" polarization for strong force. I feel like it somewhat weakens the argument of "everything else is polarized, why not gravity" if the other forces are polarized in unique ways.