/sci/ - Science & Math

[Anonymous No.6139063]

What the hell is dark matter/dark energy?

Is there any good, leading theories about this stuff?

>protoplanetary disc not related

[Anonymous No.6139092]

No one knows what they are. Dark matter and dark energy are the names we've given to unsolved cosmology problems. Either our understanding of gravity is very wrong or there is mass and a form of energy in the universe we are unable to detect. If dark matter does exist all we know about it is that it has gravitational mass, but does not emit any electromagnetic radiation. If dark energy exists all we know about it is that it causes the universe's to expand, but we can't detect it anywhere on Earth.

[Anonymous No.6139097]

It's a term usually reserved for matter we can't interact with yet.

I've seen counter-ideas to dark matter. One being that the enormously fast spin of a galaxy, is causing the discrepancy.

Another idea is that photons have rest mass.

[Anonymous No.6139099]

>dark matter
lel

http://science.slashdot.org/story/13/10/30/1749202/most-sensitive-detector-yet-fails-to-find-any-signs-of-dark-matter

[Anonymous No.6139102]

Something stupid like gravity but works at much greater distance/weaker power than gravity.

IE we have no idea what anything is and we just make shit up to explain it. So no different than anything else really.

[Anonymous No.6139108]

Dark energy and dark matter aren't really similar. Dark energy is the source of Hubble expansion and seems to be a physical constant, although its origin is unknown (there are in fact some theories, but none are widely accepted). It serves as a uniform negative pressure everywhere in the universe.

Dark matter is probably more similar to ordinary "matter," but in some ways is even more mysterious. It's just the term we give the large "missing" mass in galaxies and galaxy clusters which does not emit any light. Some of the mass is just dim objects like planets and asteroids and neutrinos, but those don't contribute nearly enough. Until recently, a number of hypothetical supersymmetric particles were leading contenders, but supersymmetry is rapidly falling out of fashion due to results at the LHC, and there were always problems with these explanations of dark matter anyway.

It is still generally believed that dark matter particles are not really completely "dark" but actually interact through the weak force (WIMPs), and enormous detectors similar to those designed to detect neutrinos have been set up in mountains and similar places. So far no dark matter particles have been detected. Then again, we don't really know what we're looking for.

Dark matter and dark energy are undoubtedly the greatest mysteries in astrophysics today.

[Anonymous No.6139120]

dark matter is dark because it emits dark photons

[Anonymous No.6139121]

>>6139120
spooky

[Anonymous No.6139130]

>>6139120
>>6139121
Basically the dark world belongs in outland and is only a subject that warlocks study deeply.

[Anonymous No.6139131]

Gravity is another problem ^^
It's actually a change in the orientation of space itself, i think einstein said..
So if it makes something change direction, well that's all well and good
What about if it accelerates?

[Anonymous No.6139144]

>>6139131
>Gravity is another problem ^^
>It's actually a change in the orientation of space itself
It doesn't change the orientation of space, just the curvature (specifically the Einstein tensor).

[Anonymous No.6139167]

>>6139144
ah, so it kind of flexes?
what happens if you step on a piece of flexed space, and then it unflexes? =)

[Anonymous No.6139168]

similarly, if something in orbit is travelling in a straight line on curved space... why does velocity affect orbits?

[Anonymous No.6139169]

One of the most intuitive and plausible theories out there about dark energy is Quantum Vacuum energy.

Because of the Unceirtainty Principle, given enough time, a seemingly perfect vacuum, might actually have some photons in it, enough to create electron-positron pairs out of them. These pairs don't last very long, since they attract each other and anihilate each other.
This way, what was measured as vacuum, actually has some particles in it, although definetely small considering everyday experience and even sophisticated experimental measuring.
The thing is there is so much of this vacuum around galaxies, that it is supposed to matter a great deal.

[Anonymous No.6139170]

>>6139167
antigravity? ^^

[Anonymous No.6139186]

>>6139168
I thought g-force for a second, but if it's traveling in a straight line... there shouldn't be any g-force?

[Anonymous No.6139188]

alright, why are we building detectors if we have no goddamn clue what it is we're trying to detect except that we dont know what it is?

[Anonymous No.6139195]

g-force / centrifugal force

[Anonymous No.6139201]

=) i guess dark matter / energy are probably just the bits of gravity we haven't figured out yet..
dark energy sounds like a fancy name for antigravity =D

[Anonymous No.6139219]

>>6139188
Welcome to science.

[Anonymous No.6139224]

The Holy Bible says nothing of the so called "dark matter" so we may only assume it's all just a devil's attempt to take our attention off of the only thing that really matters - praising the Lord.

Alleluia.

[Anonymous No.6139228]

>>6139188
We have hypotheses about what it might be (susy particles, axions, etc.). We're testing these.

[Anonymous No.6139269]

Dark energy and matter are energy and matter that originated from the dark ages.

[Anonymous No.6139305]

Why couldn't it be just more black holes and super dense objects that are producing the gravitational effects thought to be dark matter? We don't need dark matter if we have more dense regular matter. And frankly, if dark matter interacts with gravity, we should be able to detect it fairly easily but that hasn't happened.

[Anonymous No.6139309]

>>6139305
>if dark matter interacts with gravity, we should be able to detect it fairly easily but that hasn't happened.
But it has, but measuring the rotation of galaxies and finding it not match up with expectation.
How else would we detect it? Interacting gravitationally doesn't give us many ways to detect it.
Also, dark "normal" matter has been consider a candidate for dark matter (note that it would still be dark matter because it is DARK), but generally this is believed to be unable to account for what we measure.

[Anonymous No.6139320]

>>6139309
I mean local detection. Since it's interacting with gravity, it's interacting with normal matter, our normal matter. It should be around us on Earth. If so, it is added an increased gravity and throwing off our equations. But that's not happening because it isn't real.

[Anonymous No.6139640]

>>6139320
The density of quantum vacuum is too small for our current detection devices. Maybe some different methods might circumvent that, and it could be measured like the Casimir force was.

[Anonymous No.6139658]

Does anyone else believe that it seems more likely there is another factor of gravity we haven't yet figured out that would solve the dark matter problem, and that there actually isn't a form of matter that doesn't interact with radiation?

[Anonymous No.6139684]

>>6139658
Yes, it's like the Aether Postulate, just waiting for the next Einstein to figure out what's really going on, so we can do away with this silly hand waving.

[Anonymous No.6139692]

>>6139684
Thats what the guys with the MOND theories came with. Recently they did a version compatible with GR, very interesting cosmological results.

It is very hard to test them because they are almost ad-hoc additions, with adjusting parameters that would change with this or that expemerimental result.
If they could develop the theory directly from a simplified framework, like Newton took Kepler elliptical orbits and translated to a simple axial force, then they would be very convincing.

[Anonymous No.6139698]

>>6139168
Well, light travels in a straight line. Not much else does.

[Anonymous No.6139704]

>>6139169
Vacuum energy is a fact, not a theory, but the explanation of vacuum energy is less clear. Virtual particles may only be one of multiple contributions to the vacuum energy.

[Violent Simians Guy No.6139740]

Dark matter may be objects, like MACHOs or WIMPs (two good categorizations of understanding DM objects). It may be that gravity acts differently over intergalactic distances. But the latter stuff, falling under the aegis of MOND (modified Newtonian dynamics) isn't justifying itself well at all. So the searches for MACHOs and WIMPs soldier on as likelihood demands.

[Anonymous No.6139742]

>>6139169
Explain Dark Matter halos around galaxies using this theory. Oh wait, you can't

[Anonymous No.6139749]

>>6139658

Yes I do and I believe it is a major problem of current research as the idea of dark matter is so heavily promoted as being correct thus restricting research on other possibilities. I find the idea of dark matter to be completely ridiculous but apparently the idea of non observable matter is more plausible than human error. That makes sense.

[Anonymous No.6139751]

>>6139063
>What the hell is dark matter/dark energy?

dark matter doesn't exist. it's most probably some kind of a time-space anomaly that we do not understand yet.

dark energy is the energy of the empty space.

[Violent Simians Guy No.6139754]

>>6139305

Look, you need to understand gravity. We've already detected the DM via gravity... it's clearly affected galactic mass (via lensing) and galactic rotation. The problem is that we can't electromagnetically see this stuff. And that's a bit curious since on average it's 90% of the stuff in a galaxy. How the heck are we missing "seeing" 90% of a galaxy?

So we painstakingly try to find particles (WIMPs) or bulk masses (MACHOs), and these are hard as fuck to find. Dude, consider how hard it is to find something barely hot enough to emit radiation, or cold (effectively non-emitting), and measuring miles in diameter (which over galactic distance is negligible). Try to find this damn thing even a few lightyears away. That's the next best thing to invisibility.

[Anonymous No.6139757]

>>6139658
When a better model comes along, that is the model we will use. To date, dark matter is the best one for dealing with the observational results. When dark matter doesn't actually explain the results are when problems should arise, such as how the failure of the aether theory to explain various results concerning light led to acceptance of special relativity. The biggest failure of dark matter is the failure to detect it in particle experiments, but this could be due to many parameters which do not influence the application of the theory to observational data.

[Anonymous No.6139762]

>>6139063
What is better to do as uni for studying such things? Astronomy or astrphyiscs?

[Anonymous No.6139796]

>>6139754
guys, I think we just saw VSG being correct for an entire post for the first time ever. somebody screencap this moment!

[Anonymous No.6139798]

>>6139762
At a guess I would say astrophysics, but from what I have seen, astronomy = astrophysics at this point.

[Anonymous No.6139815]

So, basically Dark Matter is the Aether/Ether theory of our age? I see some rather uncanny parallels. A theory developed not from direct observation, but developed to fill in the gaps because we didn't have the right info. Seems like bad science.

pic unrelatedish

[Anonymous No.6139816]

>>6139796
I know I read that and was like "wow i don't want to punch him in the teeth something must have gone awry in the universe..."

[Anonymous No.6139821]

>>6139099

>an experiment helps to narrow down the search parameters for dark matter

is the actual message here, which is useful on its own. Shaming negative experimental results is extremely toxic to scientific progress.

[Anonymous No.6139826]

>>6139821
Truth. It's the "slut-shaming" of our field.

[Anonymous No.6139828]

>>6139826
Truth is that dark matter particle doesn't exist and we don't have a good model to account for what we see.

ps: that pic… i went to a slut walk in my town and picked up a chick. we had sex after first date. gotta love sluts & whores!

[Anonymous No.6139831]

>>6139815

It's not totally impossible that it's the 'aether theory' of our age, but aether wasn't 'bad science'. Given what was known at the time it served as a useful explanation of light propagation, and a useful absolute frame of reference for all physical processes. It was wrong*, but it wasn't necessarily 'bad science'.

*Funnily enough, cosmic microwave background can be taken to be an absolute frame of reference (eg. in cosmology), which was one of the properties of aether.

[Anonymous No.6139834]

>>6139828
>Truth is that dark matter particle doesn't exist

How do you know anon? You could revolutionise the field if you only showed us your research.

[Anonymous No.6139837]

>>6139099
Yet, from what we believe we know of gravity we can observe its effect

[Anonymous No.6139839]

>What the hell is dark matter/dark energy?

pic related

[Anonymous No.6139846]

>>6139834
experiments show it doesn't exist. Look into LUX results from few days ago.

[Anonymous No.6139852]

>>6139846

What the LUX experiment showed is that there is no dark matter within the parameters of the LUX experiment (which was mostly high-mass WIMPs).

[Anonymous No.6139858]

>>6139852
and we've analyzed all of the lower energies and eliminated light WIMPs.

[Anonymous No.6139862]

>>6139858

But WIMPs aren't the only dark matter candidates.

I don't understand why these experiments piss people off so much. Tighter constraints are a good thing. We're closer to either determining what dark matter is exactly, or ruling it out altogether, both of which are positive outcomes.

[Anonymous No.6139865]

>>6139828
yeah ironically that would be a great place to pick up women. that kind of proves their point in a weird way though, sex is good, free for all, no shame. as for dark matter particles not existing....no idea bro.

[Anonymous No.6139869]

>>6139862
We’ve eliminated ALL of the lighter energies that CERN could test and the higher ones were eliminated by LUX.

So you can still kvetch about MUH DARK ENERGY all you want since it very likely doesn't exist.

Funding for future DM particle search is now completely dry. Time to look back at alternative theories of DM effects.

[Anonymous No.6139873]

>>6139865
yeah but you wouldn't wanna date long-term one of these whores or start a family with them. it would be a disaster. also, wear condoms.

[Anonymous No.6139971]

>>6139063
>What the hell is dark matter/dark energy?

We only know to what extent our speculation and our math fails to completely work to our satisfaction.

Se we invent a black-box term to get the math to work out. We are quite precise in our invention.
We design instruments to detect this stuff that the math predicts is there. Instruments fail, time after
time.

You always need to consider the fact that it might be something else in the math that is wrong.
Otherwise, you might just as well attribute it to unicorns.

[Anonymous No.6139984]

>>6139869
Again, there are no results which really conflict with the dark matter model other than particle results. There is no results astronomically suggesting that the dark matter hypothesis does not work while there is a descent amount against all the modified gravities we have come up with thus far.

This could just mean we have not come up with the correct modified gravity, but in order to really do this with any precision, we need an astronomical observation that breaks the dark matter model in an irreconcilable way. Otherwise, we are just making shots in the dark with little to guide our probing and any good model will just be the result of blind luck at guessing it.

[Anonymous No.6139991]

>>6139984
>Again, there are no results which really conflict with the dark matter model other than particle results.

we haven't found baryonic or non-baryonic matter that would account for DM. are you that thick? you might as well call it UNICORNS like the guy above you suggested, because it doesn't fucking exist.

[Anonymous No.6140001]

>>6139869
No. You can only eliminate particles with a cross section above a threshold. No one who knows anything would claim it has been ruled out.


>So you can still kvetch about MUH DARK ENERGY all you want since it very likely doesn't exist.
Confusing the two is a clear sign you know nothing.

[Anonymous No.6140006]

>>6139991
Did you read what I wrote? Or understand it? The failure to detect dark matter in particle experiments would be the those particle results in conflict with dark matter. And this is not a failure of the dark matter model as a whole, but of the proposed particle models for it. IN order for a modified theory of gravity to be advanced meaningfully, it will have to overcome the substantial observational evidence supporting dark matter to the exclusion of all previously proposed modified gravity theories. Thus, it is not calling unicorns as the model works for the observations it is meant to explain as well as a wider range of observational phenomena where the modified gravity theories fail to do this.

[Anonymous No.6140008]

>>6139971
>You always need to consider the fact that it might be something else in the math that is wrong.
This is where your ignorance is showing. People already do this, modified theories of gravity are very much less successful than DM. DM is favored because of success.

>>6139991
>I haven't fund Iraq under my rug so it doesn't exist.
A certain parameter space has been mapped, not all of it.

[Anonymous No.6140085]

The problem is that because of the preponderance of theoretical physics, the first theory for the gravitation effects called on fancy imaginary theoretical physics, instead of relying on standard, mundane physics. Oh no, we don't want mundane physics solutions, we want weird and wacky quantum strangeness. And that's why no real evidence exists for dark matter.

[Violent Simians Guy No.6140105]

>>6139816
> disagrees with VSG
> chimp-like behavior intensifies

And you wonder why exactly I call you "violent simians"? There's not enough Fe in your average supernova to account for the irony I see here.

The issues of dark matter are easily justified. We already 'see' DM. The gravitational effects are obvious. And efforts to re-craft the law of gravity keep slapping into inconsistency. Ockham is laughing in his grave, like the sharp little bastard he is.

But efforts to fine WIMPs and MACHOs are turning out to be dauntingly difficult. If it turns out that DM is mostly located in a galactic halo, then Humanity will probably never arrive at a suitable detection scenario for them. A chunk of matter even a few lightyears away is infinitely far away, for practical outcomes. It's just too far away for our means of gathering useful info about it.

What I'm really afraid of -- and this is a wake-up call for /sci/ -- is that cosmology will end up being a purely statistical art. Check out NCG 1277. One detection and analysis suite claimed there's a 17-billion-solar-mass black hole in the galaxy, the largest by far ever found. Months later, another analysis suite was published that claimed essentially the exact opposite; that a massive BH wasn't required to explain the data. Shit! Hellfire! How the fuck are interested laymen like myself supposed to follow along?

The trend is just continuing, where by "Einstein's Telescope" (i.e. gravitational lensing) the true next step in observation must happen by resorting to whote-sky surveys combined with intensive statistical methods. That puts the mathfucks in charge. Pfui! That's the end of cosmology as a science, as far as I'm concerned.

[Anonymous No.6140106]

>>6140085
>on fancy imaginary theoretical physics
>What retards believe
GR can be derived from Lagrangian mechanics like the other forces.
>we want weird and wacky quantum strangeness
Nope, complete ignorance. GR is not quantum.

GR is hugely well established in evidence. Attempts to develop alternative theories of gravity are ongoing but much less successful.

[Anonymous No.6140120]

>>6140105
>How the fuck are interested laymen like myself supposed to follow along?
Science is not static, it changes sometimes rapidly. Reading news articles is not following along because you don't understand the discussion.

>the true next step in observation must happen by resorting to whote-sky surveys combined with intensive statistical methods. That puts the mathfucks in charge.
This is astronomy, I'm sorry it isn't as simple as you had hoped but it is still a science. The heavy use of statistics has revolutionised cosmology bringing it into the precision age. It is not becoming less of a science whatever that means.

You're a luddite, you fear what you don't understand. Open a fucking book.

[Anonymous No.6140134]

Dark Matter is to space as photons are to time.

[Anonymous No.6140312]

>>6140106
It's particles. Oh look, we have a big new particle collider, let's make everything a search for particles. To a hammer, everything looks like a nail. And it's economically attractive to promote a particle solution because more colliders will solve da problem of da hidden particles.

There is 5 times more dark matter around us right now than normal matter. It interacts with gravity, it has gravity, but we can't detect it even though it's sitting on top of us right now. Do you believe that shit? No.

[Anonymous No.6140326]

>>6140106
>GR can be derived from Lagrangian mechanics like the other forces.

GR is not a force and "Lagrangian mechanics" refers to classical mechanics and SR. What you mean is the Lagrangian formalism.

[Anonymous No.6140371]

>we can't detect it

It can and is being detected, mainly by gravitational lensing astronomy. It is normal baryonic matter and the more you look for it the more you find. It has been called 'dark' because it gives off very little light since the average temperature is about 3K, the "temperature of space" calculated by Arthur Eddington in 1926.

[Anonymous No.6140383]

>>6140371
>It can and is being detected, mainly by gravitational lensing astronomy. It is normal baryonic matter and the more you look for it the more you find. It has been called 'dark' because it gives off very little light since the average temperature is about 3K, the "temperature of space" calculated by Arthur Eddington in 1926.

No we cannot. We can detect EFFECTS of something but we cannot detect the CAUSE of it. Go learn the difference.

[Anonymous No.6140397]

Gravity has an effect on matter. It causes matter to adhere together, to clump up, to ball up, to form clouds and planets and stars. What would happen if you had a huge amount of dark matter in the universe? Gravity would cause it form dark matter clouds and planets, moons, asteroids and stars, and heat up because it's matter. Matter does that. It heats up, it jiggles around and clumps up with gravity. The theory of dark matter is ridiculous.

[Violent Simians Guy No.6140408]

>>6140120

You clearly didn't understand my complaint. Removing visual cues entirely from laymen understanding of cosmology and then adding another set of layers of math plus number crunching, makes it all just another mathematical exercise that excludes it from common understanding. You might as well just jabber about strings and manifolds.

Is English your primary language? Now I'm wondering.

[Anonymous No.6140426]

>>6140397
All proposed dark matter particles are too weakly interacting with each other or normal matter outside of gravity for this to occur. Furthermore, your argument could be equally well applied to argue that neutrinos are not real despite observation of these particles in many particle experiments.

[Anonymous No.6140463]

>>6139130
Ye i saw them in Hellfire Peninsula

[Anonymous No.6140510]

>>6140426
Neutrinos are high-energy emissions travelling near light speed, behaving closer to photons in respect to gravity. Dark matter is not a result of collisions in normal matter, and not fast moving to escape their galaxies. The most certainly would be subject to gravitational clumping.

[Anonymous No.6140550]

>>6140510
And yet neutrinos were a candidate for dark matter. The reason they failed: there aren't enough of them. Nothing to do with how fast they are.

[Anonymous No.6140578]

>>6140550
Neutrinos are considered a type of dark matter, but a minority of all dark matter. We've established that dark matter is in galactic clouds. Are they high energy clouds or low energy? A star made of dark matter seems perfectly reasonable. And since stars produce light, dark matter isn't exactly "dark". Could our sun contain dark matter?

[Anonymous No.6140622]

>>6139742
>Quantum vacuum cannot work Dark Matter
Exactly why its written:
>>6139169
>about dark energy

[Anonymous No.6140632]

>>6140408
not that dude, but I get your complaint. A hard thing about getting funding for research is convincing laymen that it's worth it. The Hubble telescope was great for that, you could show someone an incredible picture and be like "See?? Isn't this shit amazing??". The problem is that it seems we're reaching the extent of the kind of things and phenomenon we can actually observe. It's inevitable that it will get more and more esoteric. Shit is just too damn far away.

[Anonymous No.6140896]

>>6140312
>It interacts with gravity, it has gravity, but we can't detect it even though it's sitting on top of us right now.
We actually know of some dark matter that fits this. This is true for vast energy ranges of neutrinos which cannot be detected.

>>6140408
I understood it. You don't understand the issue. Complex statistics is used because the problem is complex, knowing what you know and you don't know is very important. It is no less astronomy than it was a decade ago.

[Anonymous No.6140947]

>>6140896
In theory, we should be swimming in dark matter because of the sheer amount of it, and it's presence in galaxies.

It has mass. It has gravity. I don't care how non-interactive it is, it's getting rolled into planets.

[Anonymous No.6140999]

>>6140947
>I don't care how non-interactive it is
Then you don't understand the problem.

[Anonymous No.6141018]

>>6140999
Everything interacts with gravity. And you've got tons of mass and gravity, it's gonna clump and compress, no question about it.

[Anonymous No.6141060]

>>6139837
No we're just really fucking bad at seeing shit in space and really really fucking bad at speculating.

"Dark matter" will be an embarrassment in the coming decades.

http://www.wired.co.uk/news/archive/2010-12/02/my-god-its-full-of-stars

[Anonymous No.6141065]

>>6140426
>dark matter particles
It's terms like this that make these "scientists" look like fucking lunatics. There is no basis to guess there is some magical particles floating everywhere just to make your bad math work out.

[Anonymous No.6141070]

>>6139821
>Shaming negative experimental results is extremely toxic to scientific progress.
So is wasting grant money, energy, research and time on complete dog shit.

You can research the same thing but without these bird shit theories. they have no basis.

[Anonymous No.6142794]

>>6141060

This thread deserves a bump.

I love the idea that WIMPs could easily turn out to be an illusion.

I also love the idea that this unobservable mass we're calling "dark matter" is really just the influence of gravity from very close proximity parallel realities.

If the graviton is capable of "leaking" OFF/OUT of the membrane that composes our universe, is it possible that it could leak ON/IN to another? It would make sense that the nearest universes are the most similar to our own, differing only in the outcome of maybe one quantum event.

So, the amassing of galactic super-clusters in our nearest neighboring universes might match up beautifully to the layout/distribution of our own. Gravitons leaking out of all of these universes and into each other could give the illusion that there's mass that we're somehow unable to observe?

[Anonymous No.6142830]

>>6141060
Even if the number of stars is three times larger, it would not be nearly sufficient to compensate for the missing mass problem. Even if this type of increase can be shown for all concentrated bodies that aren't hydrogen/helium clouds, you only covered less than a tenth of the missing mass. Furthermore, this kind of finding still doesn't explain the Bullet cluster data.

[Anonymous No.6142865]

God

[Anonymous No.6142874]

>>6139063
Primer fields.

[Anonymous No.6142875]

>>6142794

Para-Lel realities of jenkem.

[Anonymous No.6142986]

>>6139188
The first step in finding the cause of a reaction is running through all the variables that it >might< be, to rule out the variables that it >is not<

[Anonymous No.6142994]

Pic related

[Anonymous No.6142998]

>>6142875

>2013
>being this parental

[Anonymous No.6143447]

>>6142986
You still have to have a physical basis for that type of thinking. "Distance" between different universes, as an example, makes no sense and the parallel universe idea would still fail to explain everything that dark matter explains currently.