Dark flow

[thackley]

Scientists are now aware of this very strange phenomenon known as dark flow.

They have found a part of the universe where all the galaxies in that area are hurtling across billions of light years of space towards a single point! being 'sucked' together. And they are moving quickly.

I emphasise this is not the whole universe (which is expanding). Just a part of it. They are at a complete loss as to why this 'dark flow' is happening.

They think they may be on the verge of a new theory on the universe and that everything we think we know about the universe may not be true!

They now think galaxies spin too quickly....distant stars in galaxies spin at exactly the same as inner stars...this does not concur with laws of physics as we know it. Something must exist within the galaxies to keep them together....dark matter. The unseen matter that makes up most of the universe.

One fundamental problem....they haven't a clue what it is as it's invisible..but they know it's there.

[Dreaming Of Pandora]

Dark flow? Never heard of it... are you sure you're not referring to Dark Energy? Dark Energy is the bitch that is accelerating the universe's expansion rate.

[thackley]

No definately not. This new phenomenon is called dark flow. It is only taking place in one area. All the galaxies in that area are being pulled together by an immense force never seen before.

[Dreaming Of Pandora]

No definately not. This new phenomenon is called dark flow. It is only taking place in one area. All the galaxies in that area are being pulled together by an immense force never seen before.

Do you know The Great Attractor? Its a huge gravitational force pulling not just galaxies but clusters of galaxies including the Local Group towards a massive conglomeration of galaxies, or a galaxy supercluster. We cannot see the point of where the galaxies are headed due to the Milky Way obscuring our view of it. This sounds almost I identical to what you're talking about. Dark Matter is behind what's tuggin' us towards this gathering.
This could be the phenomenon but obviously nothing's written in stone yet.

[Txen]

Dark flow is completely different than the other "darks" of dark matter and dark energy. It's bulk flow of the entire observable universe when compared the the cosmic microwave background radiation. It is "dark" because it seems to come from beyond our observable universe. It's like there was some motion in our tiny speck of the big bang before inflation set in.

[Prometheus]

Dark flow is most likely being caused by the matter in the rest of the Universe that lies outside our Hubble Horizon...i.e. outside our little observable slice of the Universe. Just like The Great Attractor, which is essentially a giant collection of galaxies and such at a vast distance from us, so is the matter which is creating the dark flow.

If you were to travel out in the right direction, to a co-moving distance of 94 billion light years from our galaxy...to a similar position in the next section of the Universe, you'd most likely find the same dark flow, but being produced by our own section (as well as all the others) on the one you were in at that particular time.

[Spock]

CERN are about to fire up the LHC again and all their bets are on discovering dark matter this time around.

[Mongo]

CERN are about to fire up the LHC again and all their bets are on discovering dark matter this time around.

Good luck on that. I have never been convinced of the existence of 'dark matter', and the continuing lack of experimental support for the idea only confirms my opinion. The whole reason that the idea of dark matter was invented was to explain the anomalous rotation curves of spiral galaxies, where the more distant portions were rotating too quickly to fit the observed galactic mass distributions. Another group of theories (MOND, TeVeS, MoG, etc.) propose that instead of some undetectable form of matter, the galactic rotation anomalies are caused by a modification to the laws of gravity in the very-low-acceleration regime. As it happens, a recently proposed theory of gravity being discussed on this thread (http://www.avatar-forums.com/science-forum/9250-origin-gravity-found.html) might very well provide the needed modification of classical gravity to produce the observed rotation curves, obviating the need for 'dark matter'.

[Mongo]

Here is part of the Dark Flow (http://en.wikipedia.org/wiki/Dark_flow) article in Wikipedia:

Dark flow is a name given to a net motion of galaxy clusters with respect to the cosmic microwave background radiation which was found in a 2008 study. According to standard cosmological models, the motion of galaxy clusters with respect to the cosmic microwave background should be randomly distributed in all directions. However, analyzing the three-year WMAP data using the kinematic Sunyaev-Zel'dovich effect, the authors of the study found evidence of a common motion of at least 600 km/s toward a 20-degree patch of sky between the constellations of Centaurus and Vela.

The authors suggest that the motion may be a remnant of the influence of no-longer-visible regions of the universe prior to inflation. Telescopes cannot see events earlier than about 380,000 years after the big bang, when the universe became transparent (the Cosmic Microwave Background); this corresponds to the particle horizon at a distance of about 46 billion (4.6×1010) light years. Since the matter causing the net motion in this proposal is outside this range, it would in a certain sense be outside our visible universe; however, it would still be in our past light cone.

[Neytiri_Quest]

Good luck on that. I have never been convinced of the existence of 'dark matter', and the continuing lack of experimental support for the idea only confirms my opinion. The whole reason that the idea of dark matter was invented was to explain the anomalous rotation curves of spiral galaxies, where the more distant portions were rotating too quickly to fit the observed galactic mass distributions. Another group of theories (MOND, TeVeS, MoG, etc.) propose that instead of some undetectable form of matter, the galactic rotation anomalies are caused by a modification to the laws of gravity in the very-low-acceleration regime. As it happens, a recently proposed theory of gravity being discussed on this thread (http://www.avatar-forums.com/science-forum/9250-origin-gravity-found.html) might very well provide the needed modification of classical gravity to produce the observed rotation curves, obviating the need for 'dark matter'.

I agree with you on this, Mongo. The concept of 'dark matter' has always seemed like a mere placeholder to explain the anomalous spiral galaxy rotations. It 'fits' but has never been satisfying for me. I would liken the concept to a balloon that's blown up so that you can have something to paste strips of paper on. When the paste dries, you can pop the balloon. You now have a round, solid paper-mache globe. The only purpose of the balloon was to make it possible to get to the next stage. For me, 'dark matter' serves much the same purpose, but I don't accept it as inherently 'real'.