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View Full Version : What the heck is this Dark Flow that I've been reading about?



jogleby
2008-Nov-10, 06:31 PM
I've been reading a lot lately about Dark Flow. And my thoughts on the subject are pretty much "WTF!" From what I read, all the superclusters are being pulled toward a single gravitational source that is beyond the cosmic horizon. Have these observations been confirmed? How can all the galaxies be moving toward a single point? I thought they were all been carried away from us in all directions by the expansion of the universe. And lastly, I thought gravity traveled at the speed of light. I read that we were being pulled towards the source of the gravity along with everything else, but we can't see it because the universe isn't old enough for it's light to have reached us. So how can its gravity be affecting us?

PraedSt
2008-Nov-10, 06:33 PM
I've been reading a lot lately about Dark Flow.

Where from jogleboy?

sabianq
2008-Nov-10, 06:55 PM
I would think this is what the poster is referring to.
I had seen the same news release and it piqued my interest.

http://www.astronomynow.com/080924darkflowtransportsgalaxiesacrossuniverse.htm l

The research team, lead by Alexander Kashlinsky of NASA's Goddard Space Flight Center, assembled a catalogue of over 700 galaxy clusters extending to a distance of about 4.5 billion light years, and found that the entire cluster sample is speeding towards a patch of sky between the Centaurus and Vela constellations at a rate of two million miles per hour.

"The clusters show a small but measurable velocity that is independent of the Universe's expansion and does not change as distances increase," says Kashlinsky. "We never expected to find anything like this."
but was covered/mentioned here:
176 times from bautforum.com
http://www.google.com/custom?domains=bautforum.com&q=dark+flow&sitesearch=bautforum.com&sa=Google+Search&client=pub-0569369285898441&forid=1&channel=6857792137&ie=ISO-8859-1&oe=ISO-8859-1&cof=GALT%3A%23008000%3BGL%3A1%3BDIV%3A%23336699%3B VLC%3A663399%3BAH%3Acenter%3BBGC%3AFFFFFF%3BLBGC%3 A336699%3BALC%3A0000FF%3BLC%3A0000FF%3BT%3A000000% 3BGFNT%3A0000FF%3BGIMP%3A0000FF%3BFORID%3A1&hl=en
http://www.bautforum.com/astronomy/79221-more-dark-stuff-dark-flow.html
http://www.bautforum.com/universe-today-story-comments/79207-scientists-detect-dark-flow-matter-beyond-visible-universe.html
http://www.bautforum.com/against-mainstream/79381-onesimpleprinciple-predicting-flow-dark.html


here are news links..
http://www.maths.qmw.ac.uk/~jgg/gil115.pdf
http://www.space.com/scienceastronomy/080923-dark-flows.html
http://www.foxnews.com/story/0,2933,427082,00.html
http://physicsbuzz.physicscentral.com/2008/09/go-with-dark-flow.html
http://en.wikipedia.org/wiki/Dark_flow

PraedSt
2008-Nov-10, 07:04 PM
Exceptional google-fu sabianq (as always). Thanks. :)

Gigabyte
2008-Nov-10, 07:14 PM
I mentioned it here (http://www.bautforum.com/astronomy/81030-eso-chandra-deep-field-image.html#post1360255), and killed a thread.

PraedSt
2008-Nov-10, 07:39 PM
I mentioned it here (http://www.bautforum.com/astronomy/81030-eso-chandra-deep-field-image.html#post1360255), and killed a thread.

Heh. Some threads could do with your attention.

Ok, I'm officially cosmologied out. I'm retreating to my Solar System...

mugaliens
2008-Nov-12, 12:02 AM
How can all the galaxies be moving toward a single point? I thought they were all been carried away from us in all directions by the expansion of the universe. And lastly, I thought gravity traveled at the speed of light. I read that we were being pulled towards the source of the gravity along with everything else, but we can't see it because the universe isn't old enough for it's light to have reached us. So how can its gravity be affecting us?

It's The Langoliers (http://www.imdb.com/title/tt0112040/).

Gigabyte
2008-Nov-12, 03:49 AM
It's findings like this, (which of course is disputed), that keeps the Universe interesting. Just when we think we "know" what is going on, something unexpected turns up.

Spaceman Spiff
2008-Nov-12, 02:21 PM
It's findings like this, (which of course is disputed), that keeps the Universe interesting. Just when we think we "know" what is going on, something unexpected turns up.

Ned Wright and his collaborators have a list of "beefs" (http://www.astro.ucla.edu/%7Ewright/dark-flow-errors.html) with Kashlinsky's papers.

LotusExcelle
2008-Nov-12, 02:24 PM
I have something to interject here. Is it possible that the 'unexplained' observations like this are really just mundane, well-known effects but we just aren't looking at them right? Like too-small of a slice if time to really get a sense of what is really going on?

Just a thought.

Gigabyte
2008-Nov-12, 03:11 PM
Mundane well-known factors are the first thing most people check.

Well, the acceleration anomalies with our space probes is a good example. At first it was thought, "Hey, we must have a measurement error". Which of course is the firt thing to check, when discovering the data looks like something strange is going on. Then when it shows up again and again, and you triple check everything, then it is like this latest observation and measurement thingy.

Really smart scientist start scratching their heads, and they have to publish, even when they don't like it. Because at some point you have to tell the other scientists and engineers about it. And then, if you are established and high up on the food chain, they start checking your figures. maybe do an entire new study, appropriations are sought, better technology is employed, maybe even a new satellite is launched.

If you are the low man on the pole, and the anomaly isn't important, people might not even look at your results, much less try and verify them. Instead you might get laughed at. Mocked. Ignored. Until 25, or 50, or 100 years later.

This is how new stuff often goes. Especially if a finding challenges the current opinion about the Universe.

Like telling people everything is moving because of an invisible, unmeasurable object, or force. Such ideas sound so crazy, so impossible, most people, quite naturally, scoff at the very idea.

LotusExcelle
2008-Nov-12, 03:14 PM
The satellite accel issue DID end up being mundane - its just that no one thought of it for quite some time (I'll attempt to find a link to the cause). And that's a great example, really. it isn't something new. Its just that its so obvious everyone kind of *forgot*.

Gigabyte
2008-Nov-12, 03:16 PM
Oh do tell. Because this is the first I have heard of this.

LotusExcelle
2008-Nov-12, 03:21 PM
Hmm looking. I swear I saw the solution to this somewhere.

LotusExcelle
2008-Nov-12, 03:22 PM
http://www.universetoday.com/2008/09/18/flyby-anomalies-explained/

Okay so not confirmed - still needs testing. I thought it was a confirmed thing.

Gigabyte
2008-Nov-12, 03:35 PM
This Dark Flow may be a bit harder to verify. It's going to take a while to get a satellite out there to measure things.

LotusExcelle
2008-Nov-12, 03:44 PM
It will take some time to verify it and *really* get all the data but: It does illustrate my point, I think. That it could very well be something simple and known that we just are forgetting about. And that satellite issue is a great example of it. One guy out of thousands snaps his fingers and says "hey wait a second. It really IS simple." in a sense. Obviously we're still waiting for a final answer on that one but the fact that his explanation doesn't require any unknowns and in fact applies (correctly) KNOWN physics...

Anyway. Sorry if I came across as argumentative on that point. And I may have hijacked the thread there.

Gigabyte
2008-Nov-12, 03:50 PM
Not at all. I am totally down with somebody pointing out that it might be a matter of missing the obvious.

"his explanation doesn't require any unknowns and in fact applies (correctly) KNOWN physics"

LotusExcelle
2008-Nov-12, 03:53 PM
Ah excellent. Sometimes I come across differently than I mean to so I was a little worried there.

Gigabyte
2008-Nov-12, 04:33 PM
I think we all sometimes come across differently than we mean to. It takes care and effort to write so that there is no misunderstanding. Even then, differences in culture and language can lead to errors in transmission, as well as reception.