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(Science Alert)   "What's the (dark) matter, baby?"   (sciencealert.com) divider line
    More: Interesting, Dark matter, Universe, sensitive dark matter detector, Matter, dark matter, dark energy, XENON1T, Physical cosmology  
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998 clicks; posted to STEM » on 19 Sep 2021 at 7:50 AM (4 weeks ago)   |   Favorite    |   share:  Share on Twitter share via Email Share on Facebook



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2021-09-19 7:54:32 AM  
Surprised the BBC didn't report this
 
2021-09-19 8:25:58 AM  
I don't buy dark matter. I think it is a miscalculation.
 
2021-09-19 8:35:54 AM  

drjekel_mrhyde: Surprised the BBC didn't report this


They were busy with a different story...

Fark user imageView Full Size
 
2021-09-19 8:56:41 AM  

johnphantom: I don't buy dark matter. I think it is a miscalculation.


I'll make sure to mention that to all the dark matter physicists I work with next time I'm underground in the world-class particle physics lab.  I'm sure they'll want me to pass along their thanks to you for pointing out something they didn't think of.
 
2021-09-19 9:37:09 AM  

johnphantom: I don't buy dark matter. I think it is a miscalculation.


It's just a place holder. Their calculations don't stand up to reality unless something else is shoved into the equation so they are calling it dark matter.  It's like putting a letter into an incomplete mathematical equation.  Eventually they will figure out why he equations don't balance and they will reveal something like light has mass and then drop the whole dark matter idea.  They can't just openly say that their equations don't work or else that will just fuel the whole scientists are liars crowd.
 
2021-09-19 10:07:26 AM  
I see where Subby is going with this...

2.bp.blogspot.comView Full Size
 
2021-09-19 10:57:18 AM  

johnphantom: I don't buy dark matter. I think it is a miscalculation.


It's a tough sell, for sure. As mentioned above, it's a mathematical construct that fits very nicely with what we observe and what we already seem to know. Something like dark energy has been around since Einstein's relativity equations and dark matter has been around since we noticed galaxy clusters don't move exactly the way our math says they should. Other theories exist but don't hold up as well as dark matter or dark energy.

Every now and then, I like to have a few drinks and postulate that DE is just a photon losing energy over vast distances through some unknown mechanism and DM is just a construct of our misunderstanding of gravity. Then I sober up and realize I am no where near as smart as the physicists that work on DE and DM so I have to accept that, for now, these two ideas are our best bets to explain what we observe.
 
2021-09-19 11:29:53 AM  

johnphantom: I don't buy dark matter. I think it is a miscalculation.


A miscalculation coming from many lines of independent evidence? If it was a single line evidence, you might have inaccurate observations. Not miscalculation though as a few thousand of specialists have repeated the calculations.
 
2021-09-19 12:03:35 PM  

TheMysteriousStranger: johnphantom: I don't buy dark matter. I think it is a miscalculation.

A miscalculation coming from many lines of independent evidence? If it was a single line evidence, you might have inaccurate observations. Not miscalculation though as a few thousand of specialists have repeated the calculations.


I'm sure there were a lot of very smart people working on the mystery of the luminiferous ether, too, until there weren't. It's the kind of stuff that doesn't show up on the old resume.
 
2021-09-19 1:16:53 PM  

zimbomba63: TheMysteriousStranger: johnphantom: I don't buy dark matter. I think it is a miscalculation.

A miscalculation coming from many lines of independent evidence? If it was a single line evidence, you might have inaccurate observations. Not miscalculation though as a few thousand of specialists have repeated the calculations.

I'm sure there were a lot of very smart people working on the mystery of the luminiferous ether, too, until there weren't. It's the kind of stuff that doesn't show up on the old resume.


You mean like Lorentz?  The guy who came up with the space dilation equations that Einstein explained?  The equations are still named after him.  Also nearly all the phlogiston chemists had it nearly right and you could use most of their results after substituting the correct gasses (phlogiston was merely lack of oxygen, and they had a bunch of things like "dry air" = CO2).

Also, any idea how much 3.2 tonnes of Xenon costs?  Granted, it isn't getting used up, but there's a reason (cost) that starlink satellites use Krypton, even though it has lower thrust and efficiency than Xenon.
 
2021-09-19 1:47:14 PM  

Noah_Tall: johnphantom: I don't buy dark matter. I think it is a miscalculation.

It's just a place holder. Their calculations don't stand up to reality unless something else is shoved into the equation so they are calling it dark matter.  It's like putting a letter into an incomplete mathematical equation.  Eventually they will figure out why he equations don't balance and they will reveal something like light has mass and then drop the whole dark matter idea.  They can't just openly say that their equations don't work or else that will just fuel the whole scientists are liars crowd.


Light does have mass. There is a kind of famous equation that tells you how much. Not very much.
 
2021-09-19 2:08:07 PM  

johnphantom: I don't buy dark matter. I think it is a miscalculation.


How can you form an opinion on something you refuse to even understand? Nobody's asking you to believe dark matter is real like it's the second coming. But I tried to explain the basic concept to you last time around and you wouldn't even listen.
 
2021-09-19 2:46:36 PM  

johnphantom: I don't buy dark matter. I think it is a miscalculation.


Just a rounding error you get when you only call particles we can measure particles.
 
2021-09-19 2:47:39 PM  

Tranquil Hegemony: johnphantom: I don't buy dark matter. I think it is a miscalculation.

How can you form an opinion on something you refuse to even understand? Nobody's asking you to believe dark matter is real like it's the second coming. But I tried to explain the basic concept to you last time around and you wouldn't even listen.



How can you form an opinion on something nobody understands?
 
2021-09-19 2:50:30 PM  

Tranquil Hegemony: johnphantom: I don't buy dark matter. I think it is a miscalculation.

How can you form an opinion on something you refuse to even understand? Nobody's asking you to believe dark matter is real like it's the second coming. But I tried to explain the basic concept to you last time around and you wouldn't even listen.


This is what the article says:

Dark energy, like dark matter, is unknown to us. Dark matter is the name we give to mass we can't detect directly. We infer its existence because there's more gravity in the Universe than we can account for by tallying the stuff we can detect - way more.
 
2021-09-19 2:51:18 PM  

johnphantom: Tranquil Hegemony: johnphantom: I don't buy dark matter. I think it is a miscalculation.

How can you form an opinion on something you refuse to even understand? Nobody's asking you to believe dark matter is real like it's the second coming. But I tried to explain the basic concept to you last time around and you wouldn't even listen.


How can you form an opinion on something nobody understands?


I explained it to you in terms of how particles interact with forces. Are you telling me that you think nobody understands how that works?
 
2021-09-19 2:52:38 PM  

johnphantom: I don't buy dark matter. I think it is a miscalculation.


As you say in every dark matter thread without actually understanding it
 
2021-09-19 2:52:42 PM  

johnphantom: Tranquil Hegemony: johnphantom: I don't buy dark matter. I think it is a miscalculation.

How can you form an opinion on something you refuse to even understand? Nobody's asking you to believe dark matter is real like it's the second coming. But I tried to explain the basic concept to you last time around and you wouldn't even listen.

This is what the article says:

Dark energy, like dark matter, is unknown to us. Dark matter is the name we give to mass we can't detect directly. We infer its existence because there's more gravity in the Universe than we can account for by tallying the stuff we can detect - way more.


Yes, that is what the articles says. The article is about dark energy, not dark matter. You're the one who thinks WIMP theories are "magic" because you don't understand how particles interact with forces.
 
2021-09-19 2:55:04 PM  

Tranquil Hegemony: johnphantom: Tranquil Hegemony: johnphantom: I don't buy dark matter. I think it is a miscalculation.

How can you form an opinion on something you refuse to even understand? Nobody's asking you to believe dark matter is real like it's the second coming. But I tried to explain the basic concept to you last time around and you wouldn't even listen.

This is what the article says:

Dark energy, like dark matter, is unknown to us. Dark matter is the name we give to mass we can't detect directly. We infer its existence because there's more gravity in the Universe than we can account for by tallying the stuff we can detect - way more.

Yes, that is what the articles says. The article is about dark energy, not dark matter. You're the one who thinks WIMP theories are "magic" because you don't understand how particles interact with forces.


Go away.
 
2021-09-19 3:00:17 PM  
Quarks interact with the strong force (color charge), electromagnetism (electric charge), gravity (mass), and the weak force as they experience radioactive decay. That gives us lots of ways to interact with them, and measure them.

Electrons do not interact with the strong force. In any way. But they still interact with the weak force, EM, and gravity.

Neutrinos do not interact with the strong force OR electromagnetism. Only the weak force, and gravity. That makes then extremely difficult to detect, but via ingenuity, we've managed to do it.

The theorized dark matter particles only interact with gravity. That's it. No other forces. So, if they exist, they'd be even harder to detect than neutrinos. This is the model; you do not have to "believe" it or accept it as gospel. It's a THEORY.

Let's talk about another particle we've never detected - the graviton. The theorized force-carrying particle for gravity. And with gravity already being weak as shiat, a single quantum of such may be so incredibly weak we may never actually detect them. But, we can theorize them, we can use the math we've worked out to imagine a massless spin-2 boson that, if it exists, would give rise to a force indistinguishable from gravitation.

So, if we imagine a spin-1/2 fermion with mass and no other force couplings, it would give rise to a phenomenon indistinguishable from dark matter.

Do you get it now? Or are you just going to call this "magic" like last time and go on pretending you have any idea what science is about?
 
2021-09-19 3:01:23 PM  

johnphantom: Tranquil Hegemony: johnphantom: Tranquil Hegemony: johnphantom: I don't buy dark matter. I think it is a miscalculation.

How can you form an opinion on something you refuse to even understand? Nobody's asking you to believe dark matter is real like it's the second coming. But I tried to explain the basic concept to you last time around and you wouldn't even listen.

This is what the article says:

Dark energy, like dark matter, is unknown to us. Dark matter is the name we give to mass we can't detect directly. We infer its existence because there's more gravity in the Universe than we can account for by tallying the stuff we can detect - way more.

Yes, that is what the articles says. The article is about dark energy, not dark matter. You're the one who thinks WIMP theories are "magic" because you don't understand how particles interact with forces.

Go away.


Eat shiat, asshole. I've been trying to help you. And because a pop-sci article says "dark matter is unknown to us" doesn't mean shiat, moron. Now fark off.
 
2021-09-19 3:04:52 PM  

Tranquil Hegemony: johnphantom: Tranquil Hegemony: johnphantom: Tranquil Hegemony: johnphantom: I don't buy dark matter. I think it is a miscalculation.

How can you form an opinion on something you refuse to even understand? Nobody's asking you to believe dark matter is real like it's the second coming. But I tried to explain the basic concept to you last time around and you wouldn't even listen.

This is what the article says:

Dark energy, like dark matter, is unknown to us. Dark matter is the name we give to mass we can't detect directly. We infer its existence because there's more gravity in the Universe than we can account for by tallying the stuff we can detect - way more.

Yes, that is what the articles says. The article is about dark energy, not dark matter. You're the one who thinks WIMP theories are "magic" because you don't understand how particles interact with forces.

Go away.

Eat shiat, asshole. I've been trying to help you. And because a pop-sci article says "dark matter is unknown to us" doesn't mean shiat, moron. Now fark off.


LOL can't take having your ass handed to you? I bet you are an atheist too, that thinks we know everything about the universe there is to know. You would be that f*cking stupid.
 
2021-09-19 3:06:03 PM  

johnphantom: LOL can't take having your ass handed to you? I bet you are an atheist too, that thinks we know everything about the universe there is to know. You would be that f*cking stupid.


The fark are you even talking about? I explained dark matter to you in the time it took you to write "go away".

And you still think it's "magic" because you're a farking idiot.
 
2021-09-19 3:07:04 PM  
That was rather well-written.  Especially for ScienceAlert.

MICHELLE STARR18 SEPTEMBER 2021
Give that woman a raise.
 
2021-09-19 3:07:08 PM  

Tranquil Hegemony: johnphantom: Tranquil Hegemony: johnphantom: Tranquil Hegemony: johnphantom: I don't buy dark matter. I think it is a miscalculation.

How can you form an opinion on something you refuse to even understand? Nobody's asking you to believe dark matter is real like it's the second coming. But I tried to explain the basic concept to you last time around and you wouldn't even listen.

This is what the article says:

Dark energy, like dark matter, is unknown to us. Dark matter is the name we give to mass we can't detect directly. We infer its existence because there's more gravity in the Universe than we can account for by tallying the stuff we can detect - way more.

Yes, that is what the articles says. The article is about dark energy, not dark matter. You're the one who thinks WIMP theories are "magic" because you don't understand how particles interact with forces.

Go away.

Eat shiat, asshole. I've been trying to help you. And because a pop-sci article says "dark matter is unknown to us" doesn't mean shiat, moron. Now fark off.


cdn.discordapp.comView Full Size

Narrator: you did not learn your lesson
 
2021-09-19 3:07:11 PM  

Tranquil Hegemony: Quarks interact with the strong force (color charge), electromagnetism (electric charge), gravity (mass), and the weak force as they experience radioactive decay. That gives us lots of ways to interact with them, and measure them.

Electrons do not interact with the strong force. In any way. But they still interact with the weak force, EM, and gravity.

Neutrinos do not interact with the strong force OR electromagnetism. Only the weak force, and gravity. That makes then extremely difficult to detect, but via ingenuity, we've managed to do it.

The theorized dark matter particles only interact with gravity. That's it. No other forces. So, if they exist, they'd be even harder to detect than neutrinos. This is the model; you do not have to "believe" it or accept it as gospel. It's a THEORY.

Let's talk about another particle we've never detected - the graviton. The theorized force-carrying particle for gravity. And with gravity already being weak as shiat, a single quantum of such may be so incredibly weak we may never actually detect them. But, we can theorize them, we can use the math we've worked out to imagine a massless spin-2 boson that, if it exists, would give rise to a force indistinguishable from gravitation.

So, if we imagine a spin-1/2 fermion with mass and no other force couplings, it would give rise to a phenomenon indistinguishable from dark matter.

Do you get it now? Or are you just going to call this "magic" like last time and go on pretending you have any idea what science is about?


THERE IS NOTHING WE CAN DETECT BESIDES GRAVITY. Dark matter is a almost completely unproven theory.
 
2021-09-19 3:08:37 PM  

New Farkin User Name: Tranquil Hegemony: johnphantom: Tranquil Hegemony: johnphantom: Tranquil Hegemony: johnphantom: I don't buy dark matter. I think it is a miscalculation.

How can you form an opinion on something you refuse to even understand? Nobody's asking you to believe dark matter is real like it's the second coming. But I tried to explain the basic concept to you last time around and you wouldn't even listen.

This is what the article says:

Dark energy, like dark matter, is unknown to us. Dark matter is the name we give to mass we can't detect directly. We infer its existence because there's more gravity in the Universe than we can account for by tallying the stuff we can detect - way more.

Yes, that is what the articles says. The article is about dark energy, not dark matter. You're the one who thinks WIMP theories are "magic" because you don't understand how particles interact with forces.

Go away.

Eat shiat, asshole. I've been trying to help you. And because a pop-sci article says "dark matter is unknown to us" doesn't mean shiat, moron. Now fark off.

[cdn.discordapp.com image 590x238]
Narrator: you did not learn your lesson


I thought it was worth another shot. At least last time he didn't get shiatty. But now I have the true measure of him. I will not attempt to reason with him a third time.
 
2021-09-19 3:09:15 PM  
Do you even realize Einstein thought there was a 4th spatial dimension to explain gravity? What if the other possible dimensions explain dark matter and dark energy?

God you atheists are f*cking stupid.
 
2021-09-19 3:09:56 PM  

johnphantom: Do you even realize Einstein thought there was a 4th spatial dimension to explain gravity? What if the other possible dimensions explain dark matter and dark energy?

God you atheists are f*cking stupid.


Go away.
 
2021-09-19 3:14:13 PM  

Tranquil Hegemony: johnphantom: Do you even realize Einstein thought there was a 4th spatial dimension to explain gravity? What if the other possible dimensions explain dark matter and dark energy?

God you atheists are f*cking stupid.

Go away.

In a research paper published in the Journal of High Energy Physics, a team of physicists from UC Riverside says the presence of a fourth dimension could account for the existence of dark matter and explain why it remains invisible. "Our observed universe has three dimensions of space.


https://thedebrief.org/new-study-says​-​an-extra-dimension-may-explain-dark-ma​tter/

Wiki on dark matter:

Because dark matter has not yet been observed directly, if it exists, it must barely interact with ordinary baryonic matter and radiation, except through gravity.

Who is the moron?
 
2021-09-19 3:15:57 PM  

johnphantom: Who is the moron?


you
 
2021-09-19 3:17:01 PM  

johnphantom: Tranquil Hegemony: johnphantom: Do you even realize Einstein thought there was a 4th spatial dimension to explain gravity? What if the other possible dimensions explain dark matter and dark energy?

God you atheists are f*cking stupid.

Go away.

In a research paper published in the Journal of High Energy Physics, a team of physicists from UC Riverside says the presence of a fourth dimension could account for the existence of dark matter and explain why it remains invisible. "Our observed universe has three dimensions of space.

https://thedebrief.org/new-study-says-​an-extra-dimension-may-explain-dark-ma​tter/

Wiki on dark matter:

Because dark matter has not yet been observed directly, if it exists, it must barely interact with ordinary baryonic matter and radiation, except through gravity.

Who is the moron?


You, because that matches up perfectly with everything I've been saying.

I've been trying to explain the theory to you so that you understand the theory. A theory you are still perfectly free to disagree with. But you don't understand the theory. You refuse to understand the theory. You just go on ranting about God.
 
2021-09-19 3:17:24 PM  

New Farkin User Name: johnphantom: Who is the moron?

you


And you are to stupid to inject anything else into the conversation. Go away f*cktard.
 
2021-09-19 3:18:27 PM  

Tranquil Hegemony: johnphantom: Tranquil Hegemony: johnphantom: Do you even realize Einstein thought there was a 4th spatial dimension to explain gravity? What if the other possible dimensions explain dark matter and dark energy?

God you atheists are f*cking stupid.

Go away.

In a research paper published in the Journal of High Energy Physics, a team of physicists from UC Riverside says the presence of a fourth dimension could account for the existence of dark matter and explain why it remains invisible. "Our observed universe has three dimensions of space.

https://thedebrief.org/new-study-says-​an-extra-dimension-may-explain-dark-ma​tter/

Wiki on dark matter:

Because dark matter has not yet been observed directly, if it exists, it must barely interact with ordinary baryonic matter and radiation, except through gravity.

Who is the moron?

You, because that matches up perfectly with everything I've been saying.

I've been trying to explain the theory to you so that you understand the theory. A theory you are still perfectly free to disagree with. But you don't understand the theory. You refuse to understand the theory. You just go on ranting about God.


No, I don't believe in any god. I am correct, I am an agnostic. You atheists are just as bad if not worse than the theists, because you only picked one thing to defend.
 
2021-09-19 3:19:24 PM  

johnphantom: No, I don't believe in any god. I am correct, I am an agnostic. You atheists are just as bad if not worse than the theists, because you only picked one thing to defend.


Hey idiot - I am an agnostic. For all the fark-all that matters in the context.
 
2021-09-19 3:22:16 PM  

johnphantom: New Farkin User Name: johnphantom: Who is the moron?

you

And you are to stupid to inject anything else into the conversation. Go away f*cktard.


MINOR SPELLING MISTAKE
Youtube LiYqTcaq_Zo
 
2021-09-19 3:25:34 PM  

Tranquil Hegemony: johnphantom: No, I don't believe in any god. I am correct, I am an agnostic. You atheists are just as bad if not worse than the theists, because you only picked one thing to defend.

Hey idiot - I am an agnostic. For all the fark-all that matters in the context.


It does matter because the bulk of atheists are dumb enough to think we have figured everything out.
 
2021-09-19 3:25:54 PM  

New Farkin User Name: johnphantom: New Farkin User Name: johnphantom: Who is the moron?

you

And you are to stupid to inject anything else into the conversation. Go away f*cktard.

[Youtube-video https://www.youtube.com/embed/LiYqTcaq​_Zo]


Go away shiatposter.
 
2021-09-19 3:32:55 PM  
ITT: A lesson in why "don't play chess with a pigeon" is sound advice.
 
2021-09-19 7:07:31 PM  

johnphantom: Wiki on dark matter:

Because dark matter has not yet been observed directly, if it exists, it must barely interact with ordinary baryonic matter and radiation, except through gravity.

Who is the moron?



Citing wiki anything does not make you look smart.
 
2021-09-19 7:17:00 PM  

johnphantom: I don't buy dark matter. I think it is a miscalculation.


Oh sure, but you'd probably pay extra for white matter.
 
2021-09-19 7:53:19 PM  

Bondith: johnphantom: I don't buy dark matter. I think it is a miscalculation.

I'll make sure to mention that to all the dark matter physicists I work with next time I'm underground in the world-class particle physics lab.  I'm sure they'll want me to pass along their thanks to you for pointing out something they didn't think of.


I read the article, but now I want to know more about this!

Be gentle, my particle physics is rusty.
 
2021-09-19 7:54:04 PM  

Noah_Tall: johnphantom: I don't buy dark matter. I think it is a miscalculation.

It's just a place holder. Their calculations don't stand up to reality unless something else is shoved into the equation so they are calling it dark matter.  It's like putting a letter into an incomplete mathematical equation.  Eventually they will figure out why he equations don't balance and they will reveal something like light has mass and then drop the whole dark matter idea.  They can't just openly say that their equations don't work or else that will just fuel the whole scientists are liars crowd.


That's how modern physics works. Holes in equations suggest the existence of something, then experiments are devised to look for it where it was predicted to be. So far physicists have a superb track record when it comes to finding what the maths predict. Personally I find it to be both amazing and a bit terrifying to consider what has been found already and what is still being sought. The universe is an incredible and baffling place with a richness and complexity far beyond our ordinary day to day experiences of it.
 
2021-09-19 8:02:57 PM  

Hawk the Hawk: Bondith: johnphantom: I don't buy dark matter. I think it is a miscalculation.

I'll make sure to mention that to all the dark matter physicists I work with next time I'm underground in the world-class particle physics lab.  I'm sure they'll want me to pass along their thanks to you for pointing out something they didn't think of.

I read the article, but now I want to know more about this!

Be gentle, my particle physics is rusty.


Are you interested in dark matter, dark energy, or the research Bondith is doing? I can help with the basics in these, though I can't say exactly what he's studying, obviously
 
2021-09-19 8:09:34 PM  

New Farkin User Name: Hawk the Hawk: Bondith: johnphantom: I don't buy dark matter. I think it is a miscalculation.

I'll make sure to mention that to all the dark matter physicists I work with next time I'm underground in the world-class particle physics lab.  I'm sure they'll want me to pass along their thanks to you for pointing out something they didn't think of.

I read the article, but now I want to know more about this!

Be gentle, my particle physics is rusty.

Are you interested in dark matter, dark energy, or the research Bondith is doing? I can help with the basics in these, though I can't say exactly what he's studying, obviously


Actually, all three.  Never touched upon dark energy/ matter in my academic days, but we did touch upon the concepts behind those huge underground detectors.   I'm familiar (ish) with the concept of scintillation, but haven't seen anything about using xenon.
 
2021-09-19 8:44:05 PM  

Hawk the Hawk: New Farkin User Name: Hawk the Hawk: Bondith: johnphantom: I don't buy dark matter. I think it is a miscalculation.

I'll make sure to mention that to all the dark matter physicists I work with next time I'm underground in the world-class particle physics lab.  I'm sure they'll want me to pass along their thanks to you for pointing out something they didn't think of.

I read the article, but now I want to know more about this!

Be gentle, my particle physics is rusty.

Are you interested in dark matter, dark energy, or the research Bondith is doing? I can help with the basics in these, though I can't say exactly what he's studying, obviously

Actually, all three.  Never touched upon dark energy/ matter in my academic days, but we did touch upon the concepts behind those huge underground detectors.   I'm familiar (ish) with the concept of scintillation, but haven't seen anything about using xenon.


As far as I understand it, the detectors are all pretty simple in concept. Build a huge vat of some substance that's sensitive to being jostled by a heavy particle moving past with some way to detecting the disturbance. I believe xenon detectors use scintillation and light detection, and there are some bubble chamber type detectors that detect acoustics produced by the particles.

The most famous raison d'etre of dark matter is the issue of anomalous galactic rotation curves. If you look at a galaxy, it's pretty apparent that most of the stars are in the core of the galaxy, and their distribution becomes more sparse as you get further out. Assuming that most of the mass of the galaxy is in its stars, and given estimates of galactic mass based on the luminosity of the galaxy, you'd expect a certain rate of revolution for stars a given distance from the center, a function of speed that decreases as you go out from the galactic center*. We don't find that, at all. The rotation curve is flat, roughly invariant after a certain point, which implies that the galaxy has a fairly uniform density, and stars at the rim are rotating way too fast to be bound by the gravity produced by visible objects. The missing mass interspersed throughout the galaxy is what's theorized to be dark matter.

The obvious objections, "Maybe there's a lot of dim objects like brown and white dwarfs and black holes in the galaxy accounting for the missing mass!" and "What if gravity doesn't work the same on large scales!" have been studied a lot and have been mostly rejected. Their cases aren't helped by other evidence for dark matter, where light is being lensed by apparently nothing at all, by space that very likely has no black holes, and certainly not nearly enough conventional, baryonic objects to account for the mass.


Dark energy is pretty intuitive on its face. The bang was Big, inflation inflated the Universe, and so everything is flying away from each other (excepting local relative motion). Their relative motion to each other should be slowing down, since their mutual gravity should pull them back together. The opposite seems to be happening, where they're coming apart faster. This when you'll start hearing about negative pressure densities and thermodynamic analogies and Friedman's equations, which is also coincidentally the time of the year when I start zoning out during my lectures and remembering why I hated electrodynamics and was terrible at general relativity.

...I hate to say it, but I kind of don't buy dark energy and think it's a miscalculation (unlike our phantom buddy, I at least have some pretense at understanding its very basic principles, and as far as I know, most astronomers have no idea what the fark dark energy's deal is, a contrast with dark matter. A 22nd century problem discovered by mistake in the 20th century indeed). I'd be very surprised if the motivations behind dark matter turn out to be a complete fluke and there's nothing to discover there. If it turns out we missed something obvious and dark energy is a big pile of nothing, I wouldn't be shocked to find a lot of astronomers had letters of resignation pre-written for the very occasion, released right after the entire community stops facepalming. The cosmologists aren't stupid, however, and I clearly don't pretend to be enlightened and rational compared to them

//Still mad we can't figure out the farking Hubble constant

*note that this doesn't apply to the arms, which aren't a co-moving "rigid" body of stars and dust all moving together, but rather a pressure wave that isn't 1:1 dependent on galactic mass. it's basically a big, moving traffic jam where gas enters, gets compressed by the region of higher density, and forms new, visible stars before eventually leaving the dense region and fading away from age.
 
2021-09-19 9:20:12 PM  

johnphantom: THERE IS NOTHING WE CAN DETECT BESIDES GRAVITY. Dark matter is a almost completely unproven theory.


Dark matter isn't a theory, it's an observation. We see it, in the form of its effects on the gravitational field. We absolutely for certain know that there's something causing that effect, because again, we see the effect happening. There are a variety of hypotheses which might explain that, of which the one that fits the evidence the best is WIMPs, which posits a new kind of particle. WIMPs are a hypothesis, not a theory, and the whole purpose of this experiment is to test that hypothesis. MoND posits that our understanding of gravity is wrong. This actually fits the evidence we have worse than WIMPs, and is harder to test, and still kinda boils down to curve fitting (as you basically tweak constants at various distances until you replicate the effect). But, even though MoND doesn't require new kinds of particles, it is the explanation for the observation, the observation being what we refer to as dark matter.
 
2021-09-19 9:27:56 PM  
I am like Dark Matter to STEM Tab trolls.

Gravity is our only interaction.
 
2021-09-19 10:09:04 PM  

New Farkin User Name: As far as I understand it, the detectors are all pretty simple in concept. Build a huge vat of some substance that's sensitive to being jostled by a heavy particle moving past with some way to detecting the disturbance. I believe xenon detectors use scintillation and light detection, and there are some bubble chamber type detectors that detect acoustics produced by the particles.


I guess my stumbling block is how they're parsing out how their detections do or do not contribute to an understanding of a hypothetical particle.  Which is probably because I'm not a hypothetical physicist.

As for the rest of your post, gracias!  This hawk spent some time stroking their hawk beard whilst nodding and going 'hmm, interesting.'
 
2021-09-19 10:32:51 PM  

Hawk the Hawk: New Farkin User Name: As far as I understand it, the detectors are all pretty simple in concept. Build a huge vat of some substance that's sensitive to being jostled by a heavy particle moving past with some way to detecting the disturbance. I believe xenon detectors use scintillation and light detection, and there are some bubble chamber type detectors that detect acoustics produced by the particles.

I guess my stumbling block is how they're parsing out how their detections do or do not contribute to an understanding of a hypothetical particle.  Which is probably because I'm not a hypothetical physicist.


I used to work on detectors like this.

They can distinguish particles by the amount of energy they deposit in the scintillating medium and the decay curve for the flash, e.g., how "bright" the flash is and how quickly it fades.  Known phenomena have known brightnesses and fades.

When they get one that doesn't fall in one of those categories, they either call it noise (the sensors are far from perfect, and many kinds of noise can be identified as such) or they catalogue it and wait for another.

With enough examples of a strange "flavor" of event, they can begin to work backwards to narrow down what it may have been... this investigation is what TFA describes.

/engineer, not a high energy physicist
//those guys do not live in the same world as the rest of us
///if you encountered one walking down the street, it's likely you'd think they're homeless
 
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