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The Case for Dark Matter in the Universe

One of the most important constraints placed on any scientific theory is it has to be consistent with all of the available evidence and results. Dark matter (DM) was initially inferred from measuring the rotation curves of galaxies, which indicated galaxies had roughly 10x the mass compared to the atoms and ions observed in galaxies. While scientists do not yet know what DM is and alternative explanations have been explored, there are several cosmological pieces of evidence supporting the fact that DM accounts for 90% of the total mass in the universe. Alternative explanations (e.g. modified-Newtonian dynamics or MOND) have not been able to become full-fledged integrated theory. DM remains the only valid theory, at least until all candidate subatomic particles can be ruled out. Only then, will the search for new physics to explain the observations be necessary.

Cosmological arguments begin by noting how extraordinarily smooth the early universe was only a few years after the Big Bang. If you compare it to a sphere, the surface is perfectly smooth to better than 1/100,000. (For reference, the best polished optical surfaces a thousand times less smooth.) In contrast, the current universe is observed to be highly clumpy on all scales, except the very largest scale. All of the highly non-uniform structure seen today had to have grown gravitationally from the miniscule differences in density in the early universe. There isn’t sufficient time for structures to grow into galaxies, clusters of galaxies, and superclusters of galaxies without DM. Moreover, DM is necessary to create the ubiquitous suppermassive black holes (SMBH) in the galaxy cores. SMBH are millions and even billions of times more massive than our Sun. DM is necessary to create a deep enough gravitational well to trigger SMBH formation.

Gravitational lensing studies (both strong and weak) support the evidence for DM. DM in the intergalaxy regions inside clusters of galaxies is necessary to produce multiple images and the associated separations of very distant QSOs and active galaxies. The presence of this extra (missing) mass is inferred from X-ray observations of shocked ionized gas.

Only DM and normal gravity are necessary to explain this vast body of evidence. Put that in your pipe along with some really good weed and smoke it. I’m sorry for the length and technicality of this post, but various posts in the past have poo-pooed DM since we don’t know all there is to know about it.

TheAstroChuck 8 Sep 4

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18 comments

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Well constructed summary of DM. Thank you for your post and the technical nature was fine given your topic.

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If I truly understood what dark matter is, I would make an astute observation.

Hey, what about them ducks???

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Come up with your own theories. Science has been P hacked to death and the journal system is a joke. Bring back classical mechanics that actually knew what it was doing. not this hippy bad math quantum physics and relativity.

@TheAstroChuck Look up GPS relativity myth. GPS about the relation between the satellites which would change eventually between the satellites if there was relativity. One of the heads of GPS was quoted as saying relativity doesn't exist. There is also no laboratory tests for Relativity. Trust me, it costs you nothing to come up with your own theories and trust me, it takes people who aren't trying to be smart to see the truth. People who are trying to be smart make things messy because they don't want others to learn their knowledge. Just learn the SI units and the math and if you have a problem go back further to simpler subjects till you have the ground work knowledge to learn the later info.

@TheAstroChuck Great for you, you have credentials. I'm not saying you are stupid. just try and come up with your own ideas. If you want to call me a conspiracy theorist that is fine, but i tend to not label information emotionally. try and look into what i am saying instead of insulting me. I will just look at both sides of the argument and choose the most logical. If you look at matter the theories don't work. They had to invent a ghost particle called the neutrino which takes 2 light years of lead to stop to make the theory stay relevant. There are superluminal jets which aren't at the supposed angle that causes the optical illusion of being faster than light. Just look into counter arguments of things that are supposed to considered science fact. Classical mechanics is the true nature of things science has gone away from that because of statistics. and things have gotten very ridiculous.

@TheAstroChuck Well if you don't want to do the research you won't make a good scientist. enjoy your religious science.

@TheAstroChuck I'm studying for a doctorate in physics. But again you seem to not be able to think for yourself. you sound like one of those kids who grew up and never rebelled against anything, just agreed with everyone else's opinion and if there was anyone in authority he was your master. What kind of research do you do? I'll check out your papers.

@TheAstroChuck The video I sent you is by a PhD and people communicate differently these days. I passed a lot of math because of youtube. I'm researching spectra and the math behind Heisenberg uncertainty principle. Reasoning is what we should be using but then we developed uncertainty to explain Heisenberg math because when you plug a position of an electron into his equation you don't get a single answer for speed and if you plug a single speed into his equation you don't get a single answer for position. That is where uncertainty came from not from looking through microscopes at atoms. Ok, now if that doesn't sound like a wild idea to you I don't know what will and only a hand full of people understand uncertainty because they don't teach the equations Heisenberg used they teach the simpler Schrodinger equations. To me the math is wrong because it doesn't map to particulate theory. The idea of an electron being a wave and a particle is because of the double split experiment. Which shows interference fringes. Problem is those fringes can be generated by other phenomenon than waves. You should check out videos on the actual experiment not just on what people report about the experiment.

@TheAstroChuck Heisenberg uncertainty doesn't agree with observations. Have you studied the math. Don't make claims about knowledge you have not studied. Do you even know what uncertainty is? Using it to describe a predictable system is hilarious. I bet you heard the gold leaf story and clapped your hands like a seal. If that is all the evidence you needed for science to be right you can go back to your science stories. There is a reason the standard model doesn't work and we have to invent ghost particles like neutrinos and dark matter, there is a reason that not a single chemical predicted by quantum and particulate theory has had the properties predicted. It is because people believed and didn't question. But you go ahead and poopoo knowledge, I will go ahead and learn everything I can about everything and make up my own mind. Go ahead and let other people control your beliefs. Go ahead and think you don't have the brains because friendo you have the brains to come up with your own ideas and I bet they are smart enough to come up with something better.

@TheAstroChuck Ha ha you haven't studied any of it have you. bet you don't even have a masters.

@oliver-o-neill you have obviously never seen guys and dolls. you may end up with cider in your ear, making bets like that!

g

@TheAstroChuck. Your are on the tight track. Your antagonost, as you said has no real credibility or legitimacy. To continue to argue is like trying to convince a lemon its not a citrus. Pearls before swine.

0

It would be neat to find that light travels faster amongst dark matter/energy-giving the illusion of greater distance or acceleration

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My thought if your interested is a little different. If you know what a time continuum is and how entropy (gravity) compresses it, it helps. I suspect dark matter/energy is nothing more than simple matter/energy occupying another continuum close to our own. Some years ago I proposed creating an altered state between two magnetic bubbles where time was (cough) different, more or less creating an impenetrable barrier.

entropy is thermodynamic not gravitational

@magicwatch artistic liscense. gravity is an effect, like a shadow, not an actual force like strong or weak force. similar to surface tension pulling two peices of paper apart in an atmosphere. the cesastion of existance of particles causes all other particles connected by spacetime to close in to full the void. more to it of course but multiverse temporal mechanics at this point in history would be pure speculation.

@magicwatch a fun read if you have the "time" 🙂 Number of the Beast by Robert Heinlein [en.wikipedia.org]

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Wow, thanks for the explanation! I've not heard it explained in such a succinct manner.

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it's amazing how despite so much evidence that dark matter exists and so little (well, NONE!) that any gods do (i am not saying that the two issues are related), lack of proof prevents people from accepting the possibility of dark matter, but lack of proof doesn't prevent people from absolutely believing in the god(s) of their choice. no one is suggesting we accept dark matter on faith, but if you talk religion, faith is the ticket! okay i shouldn't be amazed. dark matter is everywhere but gray matter is in short supply. meanwhile, gravity is pulling me back to bed for maybe another three hours. i may dream about smbh.

g

@Avicenna unlike dark matter and antimatter, there are no dark gods or light gods, not even any in between gods.

g

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My take on Dark Matter is that it explains so many things that we are unable to see even with Hubble. This means our image of the universe is not complete and brings into play the fact that "nothing" really is something. Enough study will bring up a dimensional model and image of the universe.

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Whatever dark matter is, it seems it is everywhere. It's almost as if those early theorists with their quaint notions about "ether" were actually onto something.

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What we know today about DM (or anything else for that matter) should be better than what we knew yesterday and a bit less than what we could learn/discover tomorrow.

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Gravity is definitely very interesting to me, it’s one of those subjects that seem approachable to the layperson, until you begin to approach it!

I did figure my personal escape velocity at~22 inches per hour

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I had to google several words for definitions (English is not my first language), but I feel smarter after reading this! LOL

Regarding second language.... No eres la unica, no te preocupes ?

The feeling experienced upon learning something new is curiosity's orgasm.

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Michael J. Baker, Joachim Kopp. Dark Matter Decay between Phase Transitions at the Weak Scale. Physical Review Letters, 2017; 119 ( 6 ) DOI: 10.1103/PhysRevLett.119.061801

@TheAstroChuck -- They present a new theory for the origin of DM in this paper.

Merely a point of interest relating to DM.

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Is it OK if I ponder it with a cigar? Excellent post, thank you.

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Does the DM become denser in galaxies that have larger black holes?

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No point in poo-pooing DM. The universe is what it is, it's not like DM suddenly exists because someone came up with the notion. What did humanity think about gravity before we had come to better understand its nature? DM is really just a lable until we better understand what is really out there and how to account for it.

godef Level 7 Sep 5, 2018
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I think they prefer the term, African American Matter.

Who they?

@GipsyOfNewSpain

Who they?
Who Dey think gonna beat them Bengals?

@indirect76 Well, this year's bengals are not last year bengals, so...

@Avicenna Let's just call them matter.

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