"Dark matter or invisible element?
You decide." -Toba Beta
The dark matter wars rage on and on, with both sides -- those in favor of modifying gravity and those in favor of adding an additional mass component to the Universe -- claiming victories for their own side and defeat for the other. But one piece of evidence, hitherto elusive, might finally hold the key to distinguishing one from the other: early, young, less-evolved galaxies. Billions of years ago, not as much dark matter had fallen into the inner portions of galaxies, meaning that the outer portions of rotating spirals should display less dark matter in the past than they do today.
Do smaller and/or younger galaxies obey a different gravitational or acceleration law than large, old ones? That would go a long way towards discerning between dark matter and modified gravity. Image credit: Adam Block/Mount Lemmon SkyCenter/University of Arizona.
Instead of flat rotation curves, the galaxies in the distant Universe should exhibit falling rotation curves. In a series of new papers, a team was able to observe 101 distant galaxies at relatively high redshifts, and what they found presented compelling evidence for exactly this phenomenon. As always, more and better data is needed, as it’s only a three-sigma effect so far.
The dark matter models of today (top curves) fail to match the rotation curves, as (black curve) does the no dark matter model. However, models that allow dark matter to evolve with time, as expected, match up remarkably well. Image credit: P. Lang et al., arXiv:1703.05491, submitted to ApJ.
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Good article, but the figures are somewhat confusing. The axes labels on the graphs in Figure 1 are impossible to read (at least, to my old eyes). In the last figure, it is unclear whether the black lines represent MOND or 'no MOND no DM." If the latter, then what would a MOND prediction look like on this graph?
"In time, the universe will surrender all its secrets. But it will not shout them at us… it will whisper them. Only the quietest of minds will be able to hear those whispers."
Superfluid dark matter fills 'empty' space and is displaced by ordinary matter.
As a galaxy coalesces it displaces the superfluid dark matter. The superfluid dark matter pushes back, causing the galaxy to speed up, which in turn further displaces the superfluid dark matter. This process repeats until we wind up with the galaxy rotating at the rate in which it does today.
"dark matter", whatever it is, currently looks to be the more likely explanation.
This is a simpler idea that actually predicted the latest observations:
https://gregoriobaquero.wordpress.com/2017/01/26/rame-is-dm/
“…younger galaxies do have less Dark Matter in proportion to regular matter since the mass-energy relativistic accumulation has a compounding effect over time: The higher the energy density ratio; the more mass-energy relativistic accumulation, the more mass-energy relativistic accumulation; the more gravity, the more gravity; the more mass-energy relativistic accumulation. Even though in the early universe energy density was higher, that density was more uniformly distributed. That means that the further away we look to younger galaxies, the less Dark Matter we should find.” From Gravitational Time Dilation Explains Dark Matter
No Wimps no Mond:
Dark Energy mass density calculation is right but its actual energy density is higher because its nature is different to any other form of energy we know.(Casimir Effect experiments suggest a minimum of 12 orders of magnitude higher vacuum energy density if the distance between the sphere and the plate could get logarithmically half way closer to plank scales). That density gets gradually higher the closer it is around cosmic structures when compared to the energy density at an orbiting star frame of reference due to gravitational time dilation (Galactic Shapiro delay inside a sphere with the star orbiting radius). The net effect is the accumulation of relativistic equivalent mass (Dark Matter).
Since this explanation is purely relativistic, this hypothesis could explain why there are big discrepancies between Dark Matter measurements from gravitational lensing and rotation velocities, why dwarf galaxies seem to be submerged on seas of DM, why there is not sensible higher CDM densities when calculated from inner orbiting star velocities.
Since the mechanism is accumulative, it explains why the younger the galaxy you measure the rotation speed the less “influential” Dark Matter is in that galaxy. Also, since it is mass(equivalent mass) it has inertia as observed in the bullet cluster.
The mathematical model is far from perfect but exposes a mechanism that has been overlooked because relativistic speeds are a lot higher than any possible escape velocity (not counting around black holes).
We would no need to change the standard model of particle physics (suggested by CDM’s WIMPS) nor General Relativity (suggested by MOND) . It only needs our better understanding of Dark Energy.
https://gregoriobaquero.wordpress.com/2017/02/25/on-the-nature-of-dark-…
Would these possibilities make any sense?
Thank God we have President Trump in office now who supports NASA and just signed S.442 which (1) authorizes appropriations for the National Aeronautics and Space Administration for FY 2017; (2) provides for improvements to the International Space Station program; (3) authorizes medical monitoring and treatment for former astronauts; (4) authorizes a space technology program; and (5) authorizes third-party indemnification for certain hazardous commercial space services.
IOW NASA is getting back to core space exploration instead of stupid climate change crap dumbass democrats politicise via our govt institutions.. Bunch of filthy RATS.
https://theconservativetreehouse.com/2017/03/21/president-trump-signs-n…
@6: IOW NASA is getting back to core space exploration instead of stupid climate change crap dumbass democrats politicise via our govt institutions..
Actually NASA's core mission statement included the phrase "to understand and protect the home planet" for the first 48 years of its existence. That part of it's mission was adopted in 1956, well before climate change was even a thing, so it can't possibly/ have been politically motivated by climate change-believing Democrats. Oh and by the way, that mission statement was developed by the Eisenhower administration - a Republican.
That statement was removed under the Bush administration, in 2006. So who was politicizing the issue?
IMO this is kinda like "under God" in the pledge. We find ourselves now with a 'retcon' problem; conservatives make a change to something stable and reasonable for decades, for political reasons. Then they pretend like the change was never made and their new version is the original or has some sort of historical weight to it.
@eric#7:
There are existing term for this: historical negationism. The Soviets were infamous for doing this a lot back in the day, altering photographs to remove people who had later fallen out of favour with the Communist Party and altering records and documents to make policies look better than they did. And of course it features heavily in 1984. “We’ve always been at war with Eastasia.”
Regardless of politics, I think maybe the biggest mistake NASA made was to give up on commercial satellite launch business. I think if continued NASA could do it safer and cheaper than everybody else and could make a lot money for itself.
If NASA wants to take any people to Mars, I think the most important needed tech is a (true) oxygen generator. A device that can filter CO2 from air and separate CO2 into C and O2 w/o using anything but electricity.
I think NASA tried an experiment for it but don't know if was successful.
Another important tech for Mars would be a magnetic shield against cosmic rays but don't know if it is really possible with today's tech.
@10: you mean like this? It appears we've been working fairly successfully on the principle for at least 7 years, though since that article is more PR piece than peer-reviewed research, it's hard to say how far along they've actually brought the technology.
Note also the research was funded by DOE, because the reaction also produces CO which can be used as a fuel. The current administration plans to cut such DOE research funding by 17.9%, because they don't think it's valuable. Yeah, how could producing fuel and oxygen out of sunlight and atmospheric CO2 be valuable?
If the ESO (European Southern Observatory) illustration turns out to be correct, how could MOND survive? MOND posits that gravity is stronger than the inverse square law. One assumes that this modification of gravity should not vary in time.
This is developing into the most major crisis ih physics. Maybe Dark Matter is not really matter, but a direct effect of something straight out of Quantum Physics? A leak of entanglement over cosmic distance? At least this is what I suggest. Then it would build over time.
It would survive, as it could only currently, by being a part, not the whole, of the picture. It could be some of the differences are MOND, but it is not currently possible for it to be ALL the difference seen. DM can clump and cause spatial differences quite easily, and it's not ret-conning a new change in to do so. But it doesn't have to be all of it. However, it still needs to be discovered and measured and removed for it to be possible to find any space for MOND. Or MOND has to give up trying to explain it all and propose the change, apply it, test it and then see what's left unexplained and go "Well, does DM explain this better, and is having MOND take care of X making this Y easier to explain?".
I don't understand why this would work. It seems to me that if you were looking for a variation in spin between old and young galaxies you'd look for it in a variance between blue cloud and red sequence galaxies, not high versus low redshift galaxies. Unless the theory is that all galaxies in the universe formed at exactly the same moment, you're looking at the wrong thing to determine galactic age.
It is interesting data but it almost seems to point to something being fundamentally different about the high redshift universe rather than DM halo evolution. DM theory has a lot going for it but in spiral galactic rotation curves MOND still seems to be king.
It's fairly simple. Collapse happens quicker with regular matter,able to release potential energy by radiation than dark matter, unable to do so.
So they will collapse like "light matter" but much more slowly.
So they will not be in or near galaxies and be more spherically symmetrical therefore of no gravitational effect, the further back in time you go.
What is there not to understand?
@Denier
You got it right! I have a slide show that I presented recently to my colleagues and can be found here https://www.academia.edu/s/963641e95a/the-evolving-baryonic-tully-fishe….
...fluids in nature are in a non-uniform state, as are magnetic and gravitational fields; it would be reasonable to conjecture the higgs field is non-uniform, leading to greater mass being generated in some parts of the universe than in others when field symmetry is broken; non-uniform field dynamics could account for our perception of "missing mass"; perhaps there is no mass missing at all, but rather our current cosmology doesn't account for variations in scale resulting from non-uniform higgs field densities; I suspect that once variations in higgs field densities are taken into account, the "missing mass" will turn out to be an illusion resulting from our lack hyperbolic of perspective...
...fluids in nature are in a non-uniform state, as are magnetic and gravitational fields; it would be reasonable to conjecture the higgs field is non-uniform, leading to greater mass being generated in some parts of the universe than in others when field symmetry is broken; non-uniform field dynamics could account for our perception of "missing mass"; perhaps there is no mass missing at all, but rather our current cosmology doesn't account for variations in scale resulting from non-uniform higgs field densities; I suspect that once variations in higgs field densities are taken into account, the "missing mass" will turn out to be an illusion resulting from our lack of hyperbolic perspective...
The dark matter could be the leftover effect on the space time, from the big bang.
Like yo take the straw and start blowing the ear ...