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Mysterious 'Dark Flow' May Be Tug of Other Universe - Comments

maxchax's Avatar Comment 1 by maxchax

If our universe is being swept along by this mysterious dark flow toward maybe another universe, that would mean our universe isn't the only one around. There's got to be more than one, maybe multitudes of universe and fabrics of space-time as varied and as numerous as these universes or rather multiverses are. Whew!! Can we ever even begin to fathom than the immense vastness of it all£

Sun, 21 Mar 2010 16:36:00 UTC | #450829

mordacious1's Avatar Comment 2 by mordacious1

I think the mysterious "dark flow" was caused when god ate a bad burrito.

Sun, 21 Mar 2010 16:37:00 UTC | #450830

nother person's Avatar Comment 3 by nother person

The universe is not only expanding -- it's being swept along in the direction of constellations Centaurus and Hydra at a steady clip of one million miles per hour...

Relative to what frame of reference? Like many 'science news' reports, the original research may be interesting, but this kind of journalistic gobbledygook is worthless babble.

Sun, 21 Mar 2010 16:44:00 UTC | #450833

Janus's Avatar Comment 4 by Janus

Well said, nother person.

Sun, 21 Mar 2010 17:04:00 UTC | #450841

Nunbeliever's Avatar Comment 5 by Nunbeliever

Excuse me for being stupid, but I can't understand how on earth they can measure whether the universe as a whole is "drifting" or not??? Their answer makes me even more confused:

They look at how the relic radiation from the Big Bang explosion scatters as it passes through gases in galaxy clusters, a process that is something akin to looking at stars through the bubble of Earth's atmosphere.

Can someone please explain to me in layman's terms what this is all about.

Sun, 21 Mar 2010 17:09:00 UTC | #450843

Friend Giskard's Avatar Comment 6 by Friend Giskard

One million miles per hour relative to what?

Edit: I see from Wikipedia that it is relative to the cosmic background radiation (which I congratulate myself on having sort of guessed).

Edit 2: Oh wait. The article says that the flow dates back to the first fraction of a second. But the origin of the cosmic background radiation is much more recent than that. So I'm still in baffled.

Sun, 21 Mar 2010 17:13:00 UTC | #450845

dloubet's Avatar Comment 7 by dloubet

The article suggests that the scattering of light from the MBR by distant galaxies would be different if the universe weren't travelling at a million miles an hour in the direction mentioned.

I assume it's that frame of reference.

Sun, 21 Mar 2010 17:20:00 UTC | #450847

InYourFaceNewYorker's Avatar Comment 8 by InYourFaceNewYorker

The universe is even queerer than we can suppose!

Sun, 21 Mar 2010 17:37:00 UTC | #450857

sonnygll's Avatar Comment 9 by sonnygll

The cosmic background radiation came from the big bang. The speed is relative to that. That's how they can estimate how fast it is going.

Sun, 21 Mar 2010 18:46:00 UTC | #450884

andrew.trapp's Avatar Comment 10 by andrew.trapp

File this under the truism that truth is much, much stranger than fiction.

From the article: "It's the same flow at a distance of a hundred million light-years as it is at 2.5 billion light-years and it points in the same direction and the same amplitude. It looks like the entire matter of the universe is moving from one direction to the next," Kashlinsky said.

This would seem to imply that our universe is moving at a constant velocity, not accelerating. A gravitational attraction would imply acceleration.

I'm also confused about where this other universe would be. The dark flow seems to be pointing in a certain direction, but if that were the case, and since gravitational force travels at the speed of light like any other force, then there should be a large differential in the velocity of the universe, with parts of our universe closer to the dark flow source moving faster than more distant parts.

For another universe to be exerting an attractive force on all parts of our universe equally, the other universe would have to be equidistant from ours at all points, and the only way for that to happen would be for the other universe to be separated from ours through a 4th spacial dimension. But in that case, we should not be seeing any sort of flow in any of our 3 spacial dimensions--the movement of the 2 universes relative to each other should be unmeasurable, I would think.

Sun, 21 Mar 2010 19:21:00 UTC | #450892

musubk's Avatar Comment 11 by musubk

Measured with respect to the Cosmic Microwave Background Radiation:

"The hot X-ray-emitting gas within a galaxy cluster scatters photons from the cosmic microwave background (CMB). Because galaxy clusters don't precisely follow the expansion of space, the wavelengths of scattered photons change in a way that reflects each cluster's individual motion."

From this press release:

The author has a recent paper on ArXiv talking about dark flow measurements and uncertainties:

"This would seem to imply that our universe is moving at a constant velocity, not accelerating. A gravitational attraction would imply acceleration."

I took 'same flow' to mean same direction, not same magnitude, which could be an acceleration.

Sun, 21 Mar 2010 19:52:00 UTC | #450898

Skeptic1972's Avatar Comment 12 by Skeptic1972

Perhaps what is meant is that, on average galaxies in one direction have a red shift that's a little bit more than expected, and those in the other direction a little bit less than expected.

>>>>>>>>>This would seem to imply that our universe is moving at a constant velocity, not accelerating. A gravitational attraction would imply acceleration.

Might be inexact terminology in the article. Perhaps the meaning is that the *current* movement is of a certain speed, or perhaps the acceleration is too small to measure.

Sun, 21 Mar 2010 22:10:00 UTC | #450944

glenister_m's Avatar Comment 13 by glenister_m

There is an interesting theory that we/our universe is actually inside an enormous black hole (note Krauss's lecture when he talks about us seeing a star collapse into a black hole; while someone in the black hole would see it expand like the big bang, and a Phil Phait article about black hole densities from the other year).

I was thinking about this the other day in that orbiting black holes can collide and merge. I wonder what that would be like inside the holes when they merge, and perhaps this is a sign that we are inside one and it might be approaching merging...Well I can (day)dream.

Sun, 21 Mar 2010 22:26:00 UTC | #450947

nother person's Avatar Comment 14 by nother person

Well it is very interesting. Thanks to everyone naming the frame of reference as CMB. I guess we need to replace all those illustrations of the universe as a loaf of bread with illustrations of the universe as a half a croissant. :)

Mon, 22 Mar 2010 00:06:00 UTC | #450973

William T. Dawkins's Avatar Comment 15 by William T. Dawkins

How about a metaverse loaf of bread held together by velcro.

Mon, 22 Mar 2010 03:19:00 UTC | #451015

Arjen's Avatar Comment 16 by Arjen

There is a theory which states that if ever anybody discovers exactly what the Universe is for and why it is here, it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another theory which states that this has already happened.

Douglas Adams

Mon, 22 Mar 2010 03:35:00 UTC | #451017

sandman67's Avatar Comment 17 by sandman67

The answer is obvious.....

God Did It!

Mon, 22 Mar 2010 08:46:00 UTC | #451048

gumby gumby's Avatar Comment 18 by gumby gumby

The Universe is much more than we can imagine...

Mon, 22 Mar 2010 16:37:00 UTC | #451151

Nekura's Avatar Comment 19 by Nekura

The much simpler explanation is that this is a remnant turbulent motion that our tiny section of the Big Band had prior to Inflation. The Visible Universe is not the same as The Whole Universe, so immediately suggesting that this motion is caused by another universe seems like thinking of zebras instead of horses*.

*Apologies to anyone in countries with wild zebra populations.

Tue, 23 Mar 2010 02:02:00 UTC | #451305

blayzekohime's Avatar Comment 20 by blayzekohime

Cause I didn't feel insignificant enough already, thanks :p

Tue, 23 Mar 2010 16:23:00 UTC | #451462

Irat's Avatar Comment 21 by Irat


"Whew!! Can we ever even begin to fathom than the immense vastness of it all£"

We must fathom the depths of abysmal profundity.

Tue, 23 Mar 2010 20:06:00 UTC | #451575