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View Full Version : Dark Matter is Missing From Cosmic Voids



Fraser
2008-Aug-17, 06:50 PM
Cosmic voids really are devoid of matter. Astronomers have found that even the pervasive 'dark matter' which accounts for about 80% of the mass of the universe is not present in these voids, which are areas of vast emptiness in space that can be tens of millions of light-years across. "Astronomers have wondered for [...]

More... (http://www.universetoday.com/2008/08/17/dark-matter-is-missing-from-cosmic-voids/)

GOURDHEAD
2008-Aug-18, 12:45 PM
Since the "detection" of dark matter is inferred from the gravitational reaction of "nearby" hadronic matter, I am puzzled by this claim.

01101001
2008-Aug-18, 03:32 PM
Since the "detection" of dark matter is inferred from the gravitational reaction of "nearby" hadronic matter, I am puzzled by this claim.

From a very quick read: I don't think they measured dark matter in the voids -- because they can't. They could only speculate.

They measured the voids by the absence of ordinary matter, then did simulations of ordinary and dark matter to see what kind of voids they'd expect.

They found that the ordinary/dark-simulated voids were like the ordinary-measured voids.

Don't take the opening paragraph too literally.

trinitree88
2008-Aug-18, 04:17 PM
Since the "detection" of dark matter is inferred from the gravitational reaction of "nearby" hadronic matter, I am puzzled by this claim.

Gourdhead. This is interesting because it seems to imply a discrimination in the clumping of normal baryonic matter and of dark matter. One of the papers I referred to in another thread shows that quasars exhibit a polarization that is redshift dependent on scales as large as a billion light-years (~Giga lt-yr)...the largest structures in the universe. These surveyed quasars are associated with the distribution of normal baryonic matter.
At the same time, we are now to believe that the invisible dark matter failed to follow this recipe and provides an inhomogeneity on a scale of ~ 100,000 light years, following only luminous galaxies. So the quasar polarizations, and their associated structure, and galaxies clumped differently than the dark matter...hmmmm. pete


see;http://arxiv.org/abs/astro-ph/0507274

antoniseb
2008-Aug-19, 03:16 PM
I have a dim recollection that some studies showed that the voids have a surplus of dark energy. Can anyone point me to the articles/papers on this?

Jerry
2008-Aug-20, 06:01 AM
I have a dim recollection that some studies showed that the voids have a surplus of dark energy. Can anyone point me to the articles/papers on this?
Vacuums suck?

antoniseb
2008-Aug-20, 12:06 PM
Vacuums suck?
Surplus of dark energy in voids would suggest that they blow... but such aphorisms are not the kind of paper I'm looking for.

RussT
2008-Aug-20, 10:29 PM
Surplus of dark energy in voids would suggest that they blow... but such aphorisms are not the kind of paper I'm looking for.

http://www.eso.org/outreach/press-rel/pr-1996/pr-10-96.html

You won't like this, BUT...

They do "Blow"....or more correctly..."Spew", and they (Voids between galaxy clusters) 'spew' non-baryonic DM.

BUT, the non-baryonic DM they 'spew' is NOT WIMP's.

The non-baryonic DM they 'spew' is Neutrinos, going in 'straight-line motion', at "c" in ALL directions to infinity.

It is going in ALL directions to infinity because there are Voids on ALL sides of us, and they are ALL releasing/spewing Neutrinos in straight-line motion at "c".

ALL of that non-baryonic neutrino space, is going right through ALL baryonic matter, SO it neither pushing or pulling Anything!~

trinitree88
2008-Aug-21, 11:50 PM
http://www.eso.org/outreach/press-rel/pr-1996/pr-10-96.html

SNIPPET:
ALL of that non-baryonic neutrino space, is going right through ALL baryonic matter, SO it neither pushing or pulling Anything!~
END SNIPPET

RussT. Neutrinos passing through baryonic matter transfer both energy and momentum to it. The day/night oscillation in the solar neutrino flux of ~14%, observed at the Sudbury Neutrino Observatory, clearly shows that this is the case. When a neutrino interacts via either the two charged currents,(W+ or W-, or the neutral current[Z0, typically ~ 10% of the neutrino's energy and momenta are transferred.
The first experimental results for neutral currents at CERN in Gargamelle, indicated knock-on electrons receiving this. pete

RussT
2008-Aug-24, 11:05 AM
END SNIPPET

RussT. Neutrinos passing through baryonic matter transfer both energy and momentum to it. The day/night oscillation in the solar neutrino flux of ~14%, observed at the Sudbury Neutrino Observatory, clearly shows that this is the case. When a neutrino interacts via either the two charged currents,(W+ or W-, or the neutral current[Z0, typically ~ 10% of the neutrino's energy and momenta are transferred.
The first experimental results for neutral currents at CERN in Gargamelle, indicated knock-on electrons receiving this. pete

Sorry pete, I missed this,.

Interesting...I have been meaning to ask you a few questions about this.

Hummm, then do you think that, of the billions of neutrinos going through our bodies right now, at every concievable angle, right through our brains, at every concievable angle, that ANY electrons in any of our molecules, are receiving 10% of the neutrinos energy?

And, IF this energy is being transfered, why doesn't it do it all of the time?

And, when they do the day/night solar tests, are the neutrinos that are detected, on the far side of the earth, away from the sun, considering that they go all the way through the earth, again from every conceivable angle, and from clear across the universe, from all the galaxies?

And, the sun(ETA: I meant "Earth" here) is always aligned in the direction of the "Inner" part of the Milky Way...so shouldn't there be a huge influx from that direction, in some kind of huge cone shape, funneling down to Earth? ETA: Clarify: In other words, at any given time, the side of the earth that is facing the galactic core, if Neutrinos are being 'emmited' from stars, should have a tremendously "Higher Flux" of neutrino signatures, than the other side of the earth at that time,...should it?



That's enough for now...;)

RussT
2008-Aug-26, 08:45 AM
Sorry pete, I missed this,.

Interesting...I have been meaning to ask you a few questions about this.

Hummm, then do you think that, of the billions of neutrinos going through our bodies right now, at every concievable angle, right through our brains, at every concievable angle, that ANY electrons in any of our molecules, are receiving 10% of the neutrinos energy?

And, IF this energy is being transfered, why doesn't it do it all of the time?

And, when they do the day/night solar tests, are the neutrinos that are detected, on the far side of the earth, away from the sun, considering that they go all the way through the earth, again from every conceivable angle, and from clear across the universe, from all the galaxies?

And, the sun(ETA: I meant "Earth" here) is always aligned in the direction of the "Inner" part of the Milky Way...so shouldn't there be a huge influx from that direction, in some kind of huge cone shape, funneling down to Earth? ETA: Clarify: In other words, at any given time, the side of the earth that is facing the galactic core, if Neutrinos are being 'emmited' from stars, should have a tremendously "Higher Flux" of neutrino signatures, than the other side of the earth at that time,...should it?



That's enough for now...;)

I know these are tough ones....wanna take a shot?