It looks like you're using an Ad Blocker.

Please white-list or disable AboveTopSecret.com in your ad-blocking tool.

Thank you.

 

Some features of ATS will be disabled while you continue to use an ad-blocker.

 

Why Dark Matter is Even Weirder Than You Thought

page: 1
54
<<   2  3  4 >>

log in

join
share:
+35 more 
posted on Feb, 11 2015 @ 07:08 AM
link   
Most physicists will have you believe that dark matter is nothing but a weakly interacting particle, that is to say a particle which doesn't interact much or at all with any other type of particle. In this thread I will present several scientific discoveries which strongly suggest that dark matter is much weirder than that and cannot be explained by the standard Lambda cold dark matter model.

Before I move onto the weirdness of dark matter though I want to take a few minutes to quickly refresh the readers memory on the subject of dark matter. There are three very good reasons that mainstream cosmology was forced to accept the concept of dark matter. Cosmologists may not know exactly what dark matter is, but they know the reasons something like it must exist.

The first reason for this solid faith in dark matter has to do with the rotation of galaxies. When astronomers attempted to measure the velocity of matter rotating around the disk of a galaxy they found something very strange. Based on our understanding of gravity and motion, the rotational velocity of matter should decrease with the distance from the center of the galaxy.

In other words objects further out from the center should be orbiting the galaxy at a slower velocity. However our observations tell us that the velocity essentially stays constant right out to even the most distant objects. This observation indicates that there must be a lot of invisible matter we can't see in the galaxy which is distributed differently than visible matter.



The picture above shows the predicted rotation curve vs actual observed rotation curve for a real galaxy. The flat rotation curve is not possible unless the galaxy contains a substantial amount of hidden mass we can't directly see. If this extra hidden mass did not exist the galaxy would not be able to hold its self together and would shoot apart due to the high rotational velocities.

In order to explain this flat rotation curve we find that the dark matter must be in the shape of a sphere, unlike the visible matter which is a flat disk shape. We find that this sphere of dark matter extends out much further in space than our galaxy, meaning the visible part of our galaxy is engulfed in a huge ball of dark matter which scientists call the "dark matter halo".



The second reason we believe that some sort of invisible mass must be surrounding most or all galaxies is because we can use a phenomena called gravitational lensing to actually measure the mass contained in a distant galaxy or galaxy cluster. Recall that mass curves space and can therefore alter the path of light. When light travels close to a galaxy its path will be bent in this way.

Thus large objects in space can actually act like a magnifying glass due to the way they bend and distort the light which travels around to them. By measuring the intensity of gravitational lensing around an object in space we can actually determine how much mass that object must contain. However when we do this for galaxies and galaxy clusters we run into another problem.

When we compare the amount of luminous mass in the galaxy or galaxies being measured we find that it's much lower than the mass determined by measuring the gravitational lensing. This means the object must contain some non-luminous matter which doesn't interact with light and therefore doesn't reflect light and as a result we can't directly observe it like normal matter.

The third reason is that dark matter is crucial to our understanding of how galaxies evolve and the overall structure of the universe. Our simulations are heavily reliant on dark matter to produce the properties and distribution of galaxies we see today. Cosmologists often remark that dark matter is the scaffolding which holds the universe together and allows it to grow.

Well many people don't like this idea and they invoke concepts such as Modified Newtonian Dynamics (MOND), which alters the laws of gravity in order to explain the flat rotational curves of galaxies. The problem is that it doesn't explain the excessive gravitational lensing. As a result MOND has been rejected by the scientific community in favour of weakly interacting particles.

None of this really sounds too strange so far, maybe dark matter simply is a type of invisible particle. Well there is a reason some scientists seek out alternative explanations such as MOND. In recent years the standard theory of dark matter has failed to explain many weird observations. These observations strongly suggest that dark matter is composed of something very strange.

edit on 11/2/2015 by ChaoticOrder because: (no reason given)



posted on Feb, 11 2015 @ 07:09 AM
link   
Problems with Distribution of Dark Matter


The cuspy halo problem arises from cosmological simulations that seem to indicate cold dark matter (CDM) would form cuspy distributions — that is, increasing sharply to a high value at a central point — in the most dense areas of the universe. This would imply that the center of the Milky Way, for example, should exhibit a higher dark-matter density than other areas. However, it seems rather that the centers of these galaxies likely have no cusp in the dark-matter distribution at all.

This remains an intractable problem. Speculation that the distribution of baryonic matter may somehow displace cold dark matter in the dense cores of spiral galaxies has not been substantiated by any plausible explanation or computer simulation.

Cuspy halo problem - Wikipedia



"Stars in a dwarf galaxy swarm like bees in a beehive instead of moving in nice, circular orbits like a spiral galaxy," explained Peñarrubia. "That makes it much more challenging to determine the distribution of dark matter."

Their data showed that in both cases, the dark matter is distributed uniformly over a relatively large region, several hundred light-years across. This contradicts the prediction that the density of dark matter should increase sharply toward the centers of these galaxies.

"If a dwarf galaxy were a peach, the standard cosmological model says we should find a dark matter 'pit' at the center. Instead, the first two dwarf galaxies we studied are like pitless peaches," said Peñarrubia.

Dark matter mystery deepens


Problems with Satellite Galaxies


The dwarf galaxy problem, also known as the missing satellites problem, arises from numerical cosmological simulations that predict the evolution of the distribution of matter in the universe. Dark matter seems to cluster hierarchically and in ever increasing number counts for smaller-and-smaller-sized halos. However, although there seems to be enough observed normal-sized galaxies to account for this distribution, the number of dwarf galaxies[1] is orders of magnitude lower than expected from simulation.[2] [3] For comparison, there were observed to be around 38 dwarf galaxies in the Local Group, and only around 11 orbiting the Milky Way,[1] yet one dark matter simulation predicted around 500 Milky Way dwarf satellites.[2][3]

Dwarf galaxy problem - Wikipedia



The standard model, also called the "lambda cold dark matter model," says that satellite dwarf galaxies in the Milky Way and Andromeda are expected to behave a certain way: The galaxies would form in halos of dark matter, be widely distributed and would have to move in random directions, said Marcel Pawlowski, a postdoctoral researcher in the astronomy department at Case Western Reserve University and lead author of the new study.

"But what astronomers see is different," Pawlowski said. "We see the satellite galaxies are in a huge disk and moving in the same direction within this disk, like the planets in our solar system moving in a thin plane in one direction around the sun. That's unexpected and could be a real problem."

Dwarf galaxies don't fit standard model


Problems Finding Local Dark Matter


A team using the MPG/ESO 2.2-metre telescope at ESO’s La Silla Observatory, along with other telescopes, has mapped the motions of more than 400 stars up to 13 000 light-years from the Sun. From this new data they have calculated the mass of material in the vicinity of the Sun, in a volume four times larger than ever considered before.

“The amount of mass that we derive matches very well with what we see — stars, dust and gas — in the region around the Sun,” says team leader Christian Moni Bidin (Departamento de Astronomía, Universidad de Concepción, Chile). “But this leaves no room for the extra material — dark matter — that we were expecting. Our calculations show that it should have shown up very clearly in our measurements. But it was just not there!”

Serious Blow to Dark Matter Theories?



The team, led by C. Moni Bidin used ~300 red giant stars in the Milky Way‘s thick disk to map the mass distribution of the region. To eliminate any contamination from the thin disc component, the team limited their selections to stars over 2 kiloparsecs from the galactic midplane and velocities characteristic of such stars to avoid contamination from halo stars. Once stars were selected, the team analyzed the overall velocity of the stars as a function of distance from the galactic center which would give an understanding of the mass interior to their orbits.

Using estimations on the mass from the visible stars and the interstellar medium, the team compared this visible mass to the solution for mass from the observations of the kinematics to search for a discrepancy indicative of dark matter. When the comparison was made, the team discovered that, “[t]he agreement between the visible mass and our dynamical solution is striking, and there is no need to invoke any dark component.”

Missing Milky Way dark matter


Problems with Visible/Dark Matter Ratios


Dr. Benoit Famaey (Universities of Bonn and Strasbourg) explains: "The dark matter seems to 'know' how the visible matter is distributed. They seem to conspire with each other such that the gravity of the visible matter at the characteristic radius of the dark halo is always the same. This is extremely surprising since one would rather expect the balance between visible and dark matter to strongly depend on the individual history of each galaxy."

Dr. Zhao at the SUPA Centre of Gravity notes, "The pattern that the data reveal is extremely odd. It's like finding a zoo of animals of all ages and sizes miraculously having identical, say, weight in their backbones or something. It is possible that a non-gravitational fifth force is ruling the dark matter with an invisible hand, leaving the same fingerprints on all galaxies, irrespective of their ages, shapes and sizes."

Is Unknown Force In Universe Acting On Dark Matter?



The new, relatively high-resolution WSRT measurements suggest that VIRGOHI21 is indeed a single object, ruling out previous suggestions that its rotation was an illusion caused by two passing gas clouds.

But they do confirm a mystery raised by previous studies. The object's normal matter weighs a few hundred million times the mass of the Sun. But its dark matter - inferred by studying the rotation speed of the cloud - appears to weigh at least 100 times as much.

That ratio is much higher than expected - in all other galaxies, dark matter outweighs normal matter by a factor of only 10. "Even if this is a dark galaxy, it is not what you expect to find. The number of baryons is too low," says Michael Merrifield of the University of Nottingham in the UK, who was not on Minchin's team.

'Dark galaxy' continues to puzzle astronomers


edit on 11/2/2015 by ChaoticOrder because: (no reason given)



posted on Feb, 11 2015 @ 07:23 AM
link   
a reply to: ChaoticOrder

This is the kind of thread that makes coming to ABS in the morning worthwhile. While I am a more than an avid UFO fan, I get so tired of doom/gloom/false flag threads that are woven out of whole cloth. Knowledgeable folks with contrary views about cosmology could even claim that about this thread, but I doubt it. Regardless, the OP has presented us with easy to understand info to think about as we wonder about the biggest mystery of all.


+2 more 
posted on Feb, 11 2015 @ 07:35 AM
link   
Dark matter exists only because some scientific theories had to "survive".
Calculations fails? then it's nature's fault, not theories.

One day we might have a better theory that doesn't need magic parameters to explain observations and we will look into this dark age of science like we look at ptolemy solar system.
That day may be far tho.



posted on Feb, 11 2015 @ 07:45 AM
link   
I hold that 'dark matter' is somewhat like a stem cell in our biology make up... just as a stem cell can have a gene turned on-off to develop into a specific type of cell~~~ so too does the 'dark matter' proto-particles which can develop into matter like an element or a chemical or organic precursor such as a hydro-carbon upon reaching some unknown sequence of stimulus

dark matter is like a soup of blended nixed ingredients, it can bend light with Its gravity but It has no shape or defined form or boundary like a cell membrane encloses a cell....a dark matter energy packet is waiting for the defining code for its material nature to develop and then as a particulate will fall from the void of space onto a material conglomeration of already material matter , like a planet or star or comet or molecular cloud

dark matter is first made known in the Genesis account and it is called the descriptive term 'waters of the deep'
the 'waters of the deep' can potentially become Anything, the possibilities are limited only to the material universe
it is the creation building block
edit on th28142366265211502015 by St Udio because: (no reason given)



posted on Feb, 11 2015 @ 07:51 AM
link   
a reply to: Mastronaut

I assume you haven't read the first part of this thread yet. There are many good reasons we believe that some type of invisible mass is surrounding most or all galaxies. The MOND theory simply cannot explain the range of observations which support the existence of this invisible mass. The question is not whether dark matter exists, the question is what exactly is dark matter, is it some type of particle or something even stranger.



posted on Feb, 11 2015 @ 08:00 AM
link   
So the "Missing Matter" is associated with Galaxies right? Centers of gravity are centers around something, I think they haven't a clue how massive the singularities at the center of most galaxies truly are. We can't even observe them directly, how can they tell how much mass is in there?



posted on Feb, 11 2015 @ 08:03 AM
link   
a reply to: ChaoticOrder


Ummm...I'm fairly ignorant when it comes to all of this...so bear with me...

It almost sounds like what your describing is that the "dark matter" extends as far as the gravity envelope or gravitational effect boundary...if you will...and that this dark matter binds the rotational velocity of visible mass to a constant...regardless of distance to the galactic core...much as gravity does...

Wouldn't it then be logical to assume that perhaps this dark matter and gravity are one and the same...a graviton perhaps...or as in dark matter is the "particle" and gravity the energetic effect of the particle as it relates to other particles both dark and visible...?

I wonder also if it would be right to assume that gravity has less to do with mass concentration than it does with total mass dispersion in a given system...if we include dark matter in that system as well...Hence the effect of gravitational lensing as it relates to both calculated and observed differences...

I'm also thinking that this would cause one to reconsider whether gravity really was only a curvature in space/time due to mass concentration...or something more akin to an actual force or particle itself...




YouSir



posted on Feb, 11 2015 @ 08:08 AM
link   
Couldn't the standard and even rotation of galaxies be because the universe isn't old enough for the outer edges to slow down yet? Possibly galaxies are born with such a massive rotating momentum that it will take billions of more years before the gravitational effect of the center mass can grab the outer areas enough to cause them to slow. How many times in its lifetime has our own galaxy made a round-trip? I'm an agnostic when it comes to dark matter, and take into consideration the pull of other bubble universes and unknowns which may explain the undetected missing mass. All of that said, what a nice OP presentation, thank for the work and the interesting data.



posted on Feb, 11 2015 @ 08:08 AM
link   

originally posted by: intrptr
So the "Missing Matter" is associated with Galaxies right? Centers of gravity are centers around something, I think they haven't a clue how massive the singularities at the center of most galaxies truly are. We can't even observe them directly, how can they tell how much mass is in there?

Even if the galactic cores were much larger than we think they are it still wouldn't explain the flat rotation curve, it would still have to drop off with distance from the core.



posted on Feb, 11 2015 @ 08:13 AM
link   
a reply to: YouSir


Wouldn't it then be logical to assume that perhaps this dark matter and gravity are one and the same...a graviton perhaps...or as in dark matter is the "particle" and gravity the energetic effect of the particle as it relates to other particles both dark and visible...?

Interesting idea, I haven't thought of that before. It may possibly work although I suspect it would have problems similar to MOND. I'll have to think about it some more. I do also have my own theory of dark matter which I posted on ATS some time ago: Unmasking Dark Matter and Dark Energy (with simulation results). It's a bit outdated now though, there are aspects of the theory which need correcting, but I believe it's the only theory capable of explaining all the weird properties of dark matter.



posted on Feb, 11 2015 @ 08:15 AM
link   

originally posted by: Aleister
Possibly galaxies are born with such a massive rotating momentum that it will take billions of more years before the gravitational effect of the center mass can grab the outer areas enough to cause them to slow. How many times in its lifetime has our own galaxy made a round-trip?

The problem is that they can't be rotating that fast in the first place or the galaxy would fly apart. We know that the galaxy is billions of years old and we know our solar system has completed many rotations around the galactic core.



posted on Feb, 11 2015 @ 08:24 AM
link   
a reply to: ChaoticOrder


Even if the galactic cores were much larger than we think they are it still wouldn't explain the flat rotation curve, it would still have to drop off with distance from the core.

I'm not as learned in this field as you so forgive me…

"As above so below"? The rings of Saturn come to mind… how do we account for their flat, well defined plane at the equator?



posted on Feb, 11 2015 @ 08:30 AM
link   

originally posted by: ChaoticOrder
a reply to: Mastronaut

I assume you haven't read the first part of this thread yet. There are many good reasons we believe that some type of invisible mass is surrounding most or all galaxies. The MOND theory simply cannot explain the range of observations which support the existence of this invisible mass. The question is not whether dark matter exists, the question is what exactly is dark matter, is it some type of particle or something even stranger.


I read these kind of articles since 20 years despite I'm not a scientist and it took me a lot more to understand the "hows" and "whys". My reply wasn't sensible sorry, I didn't intend to troll, but the so called "range of observations" are additional features we found just because our theories failed in the past. If convenience is the only reason to believe a theory then inflation MUST have existed despite is the most controversial part of the BB theory.

My comment has more to do with the lack of revision of scientific theories in light of new discoveries. Dark matter came up in 30s because gravitational laws were failing to explain the observations of galaxy rotation curves and other gravitational effects. However we always forget to say we don't know what gravity is and we can't effectively test it in a laboratory free of outside gravitational fields. In the FRW equations it appears as a parameter, a convenient number to make theory work.

All this enormous work that has been done on exotic physics in astronomy is built on top of other mathematical models that include unverifiable postulates. We know GR can't explain everything, and we don't have a working GUT theory, but we can't accept that they aren't "right" or we would taint the history of physics.

So I didn't want to insult you or the scientists working in this field, I'm mostly angered towards the ridicule that any other alternative theory is and will get because of career threats and how the academic and scientific world works.
Dark matter is a puzzle because it MAY NOT EXIST after all, we know there are some observations, we didn't find any dark matter btw.

MOND is just a general therm to define theories that modify Newton's laws, many of them explain galaxy rotation curves quite well, but where is it stated that the same theory must also account for gravitational lensing? Also, is this lensing really "gravitational" given that we can't see any matter where we find these distortions? It could simply be a totally different effect, maybe something much simpler than invisible uninteracting things. But how much research time has been devoted to DM and how much to MOND-like theories? Probably we need more time spent on alternatives that mines the foundation of our way of understand the cosmos, since we failed every prediction and we only find the scapegoats.

I take everything about mainstream astronomy with a big grain of salt because it's all built on top of speculative exotic theories with unprovable assumptions and tautological reasoning (cosmological redshift is my biggest culprit). My stance is that while we can't be sure if some fringe theory is closer to the truth, we can be sure that current theories are kinda "wrong" and will be surpassed by new theories in the future, not necessarily based on new observation, but on consensus about interpretation of data.

Dark matter is something needed in the FRW GR equations for the BB theory and until we find a real candidate particle or a way for this darm matter to be generated, it will remain an artifact to close a gap in a theory and not something that "exists".
Dark matter may be a mechanism more than "something", in any case it exposes fallacies in our cosmological theories and it isn't something a lot of academics are willing to discuss.
Evidence is that we can't explain movements of objects with Newtonian's mechanics at larger scales. The hypotesis is that there is a lot more mass. Is it possible that mass is separate from matter? Maybe, maybe not. However stating that DM exist and it's just a matter of what is it made of is like putting faith in a religion, so I am very prudent in not taking that stance.

I may be wrong or may be right, but I have no reason to self-censor my opinion because I don't do scientific publishing as a job nor I want an academical career. But it's very hard to prove the existence of dark matter from any scientifical point of view, and as long as we can't have a reasonable theory I'm not gonna be satisfied by current mainstream explaination. It's not a matter of having read this or that article, because most are only based on authorities and not facts. Falsifiability is the basis of scientific method, but it's something we lost far back in past regarding "accepted theories".



posted on Feb, 11 2015 @ 08:52 AM
link   
a reply to: Mastronaut


If convenience is the only reason to believe a theory then inflation MUST have existed despite is the most controversial part of the BB theory.

I don't particularly like the theory of inflation either, but that's only because we have no direct way to verify it and there are other ways to explain why the universe is so homogeneous and isotropic. The difference with dark matter is that we have methods to directly infer its existence via several different methods. Of course there are other ways to explain the flat rotation curves and the lensing effect but many of them simply don't hold up to scrutiny.


We know GR can't explain everything, and we don't have a working GUT theory, but we can't accept that they aren't "right" or we would taint the history of physics.

I agree that GR cannot explain everything, it's probably flawed in some regard which is why it's not compatible with QM. But our understanding of gravity is well enough established to know that our galaxy would fly apart were it not engulfed in some type of invisible mass. If our understanding of gravity were incorrect on such a fundamental level we'd be in big trouble.


MOND is just a general therm to define theories that modify Newton's laws, many of them explain galaxy rotation curves quite well, but where is it stated that the same theory must also account for gravitational lensing?

Of course MOND must be able to explain the excessive gravitational lensing, ideally it should be able to explain everything that dark matter helps us to explain, but it doesn't. The fact that the mass derived from the lensing effect and mass derived from the rotational velocities agree with each other definitely show us that most galaxies contain much more mass than we can see. What is responsible for that extra mass is the question.


Also, is this lensing really "gravitational" given that we can't see any matter where we find these distortions?

There is always matter where we see the distortions, the only objects large enough to produce a measurable effect are large galaxies and clusters. The problem is those objects we measure bend light far too intensely based on the luminous matter we can see in those objects.


But how much research time has been devoted to DM and how much to MOND-like theories?

A lot of time has been spent on MOND and a lot of time is still spent on MOND, but not by serious scientists. I completely agree that we need to look beyond the standard model, that's what this whole thread is about, but modified gravity theories simply aren't going to cut the mustard.

edit on 11/2/2015 by ChaoticOrder because: (no reason given)



posted on Feb, 11 2015 @ 08:54 AM
link   
Quantum Gravity predicts that dark matter is the gravitational energy of all the semi coherent prions that do not make it to becoming virtual particles.

This however raises a question, why is the Dark matter appearing clumped at certain points throughout the universe. The answer to this question may be a tantalizing glimpse at the reality that physical distance is not as we perceive it to be.

Korg.
edit on 11-2-2015 by Korg Trinity because: (no reason given)



posted on Feb, 11 2015 @ 09:02 AM
link   

originally posted by: intrptr
a reply to: ChaoticOrder

"As above so below"? The rings of Saturn come to mind… how do we account for their flat, well defined plane at the equator?

The outer part of the rings rotate slower than the inner parts, which is what we normally expect to see. The same thing happens with the moons of Jupiter, or even our entire solar system (outer planets orbit more slowly). The strange thing about the galaxy is that is doesn't follow that rule, the outer parts basically orbit at the same velocity as the inner parts.



posted on Feb, 11 2015 @ 09:16 AM
link   
a reply to: ChaoticOrder


The outer part of the rings rotate slower than the inner parts, which is what we normally expect to see. The same thing happens with the moons of Jupiter, or even our entire solar system (outer planets orbit more slowly).

You mean relative velocity ?

A figure skater spins up the closer in she pulls her arms… so I expect that to be similar.


The strange thing about the galaxy is that is doesn't follow that rule, the outer parts basically orbit at the same velocity as the inner parts.

"Basically"… our one galaxy? I'd read any link you have making that claim, if you would be so kind.

As well the "spiral arms:" are not ring like (like saturn) or planet like bodies around a star. I saw a graphic once of stars moving around the plane of the galaxy and I haven't' been able to find it. I saw what you say about the same speed of suns moving, "within the spiral arms".

Thats a little different but still the same thing. An accretion disk, based on the gravity of the parent source.

In the case of the Galaxy, a really dense one.



posted on Feb, 11 2015 @ 09:24 AM
link   
Seems like some misunderstanding is going on.

Let's take a different tact....

Sagittarius A does not have enough mass to anchor all the matter in our galaxy in place. If not for Dark Matter the galaxy should be a lot smaller in size. If the effects of dark matter could be suddenly turned off, the galaxy would be flinging stars away from it at crazy velocities.

Korg.



posted on Feb, 11 2015 @ 09:42 AM
link   
a reply to: intrptr


A figure skater spins up the closer in she pulls her arms… so I expect that to be similar.

If her hands are extended out they stay aligned with the skater but they experience more force which is why the skater tries to pull herself in as much as possible. If her hands weren't attached to her body they would fly off. The connection between the hands and shoulder is like gravity. But there is less force in the center part of her body because it's closer to the point of rotation. This is why objects which are further from the point of rotation must orbit more slowly in order to stay in orbit.

The further out you go, the weaker gravity gets, meaning the orbit must be slower in order not to overcome the force of gravity holding it in orbit. But the galaxy doesn't follow that rule, the outer objects are some what like the hands of the skater, they don't lag behind. Since distant objects around the galaxy are orbiting much faster than predicted that means the force of gravity mustn't get weaker as you move away from the galactic core, but as we know the force of gravity should be inversely proportional to the square of the distance.


"Basically"… our one galaxy? I'd read any link you have making that claim, if you would be so kind.

I used the word basically because the rotation curve would only be perfectly flat if the mass in the galaxy were perfectly distributed in a symmetrical manner, but of course galaxies aren't shaped perfectly, nor is the dark matter halo which surrounds them. It's not just our galaxy, it seems to be all galaxies we can measure. You can read more here:


A general feature of the galaxy rotation curves that have been obtained through measurement to date is that the orbital speed of stars and gas is rising or almost constant as far from the galactic centre as it can be measured: that is, stars are observed to revolve around the centre of the galaxy at increasing or the same speed over a large range of distances from the centre of the galaxy. If disc galaxies have mass distributions similar to the observed distributions of stars and gas then, the orbital speed would always decline at increasing distances in the same way as do other systems with most of their mass in the centre, such as the Solar System or the moons of Jupiter.

Galaxy rotation curve - Wikipedia


edit on 11/2/2015 by ChaoticOrder because: (no reason given)



new topics

top topics



 
54
<<   2  3  4 >>

log in

join