Precise picture of early Universe supports 'dark matter' theory

Nov 02, 2009
The QUaD collaboration uses the 2.6-meter telescope shown here to view the temperature and polarization of the cosmic microwave background, a faintly glowing relic of the hot, dense, young universe. Credit: Image courtesy of Nicolle Rager Fuller, NSF.

A detailed picture of the seeds of structures in the universe has been unveiled by an international team co-led by a Cardiff University scientist.

The team has obtained extremely precise data about the , using a telescope near the South Pole in the Antarctic.

Their measurements of the cosmic microwave background - a faintly glowing relic of the hot, dense, young universe - provide further support for the standard cosmological model of the universe. The findings confirm the model's prediction that and dark energy make up 95% of everything in existence, while ordinary matter makes up just 5%.

In a paper published in the November 1 issue of The , researchers on the QUaD project have released detailed maps of the (CMB). The researchers focused their measurements on variations in the CMB's temperature and polarization to learn about the distribution of matter in the early universe. Polarization is the direction in which vibrations travel from all light rays, which is at right angles to the ray's direction of travel.

The light from the early universe was initially unpolarized but became polarized when it struck moving matter in the very early universe. By creating maps of this polarization, the QUaD team was able to investigate not just where the matter existed, but also how it was moving. The results very closely match the temperature and polarization predicted by the existence of dark matter and dark energy in the standard cosmological model.

The team was jointly led by Professor Walter Gear, Head of the School of Physics and astronomy at Cardiff University and Professor Sarah Church of the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), jointly located at the Department of Energy's SLAC National Accelerator Laboratory and Stanford University.

Professor Gear said: "Studying the CMB radiation has given us extremely precise pictures of the Universe at just 400,000 years old. When we first started working on this project the polarization of the CMB hadn't even been detected and we thought we might be able to find something wrong with the theory. The fact that these superb data fit the theory so beautifully is in many ways even more amazing. This reinforces the view that researchers are on the right track and need to learn more about the strange nature of dark energy and dark matter if we are to fully understand the workings of the universe."

Michael Brown, of the Kavli Institute for Cosmology at the University of Cambridge, lead author of the new study added: "With these new QUaD measurements, we have tested further our standard model of the Universe. Reassuringly, the model has passed this test remarkably well."

Professor Sarah Church, Deputy Director of KIPAC, said: "When I first started in this field, some people were adamant that they understood the contents of the universe quite well. But that understanding was shattered when evidence for was discovered. Now that we again feel we have a very good understanding of what makes up the universe, it's extremely important for us to amass strong evidence using many different measurement techniques that this model is correct, so that this doesn't happen again."

Source: Cardiff University (news : web)

Explore further: Quest for extraterrestrial life not over, experts say

add to favorites email to friend print save as pdf

Related Stories

Dark energy -- 10 years on

Nov 30, 2007

Three quarters of our universe is made up of some weird, gravitationally repulsive substance that was only discovered ten years ago – dark energy. This month in Physics World, Eric Linder and Saul Perlmutter, both at the ...

Universe in crisis as experts question Big Bang model

Jul 07, 2005

The widely accepted idea that the universe began with a Big Bang could be wrong, according to astrophysicists who took part in a "Crisis in cosmology" meeting in Portugal and reported in this month's Physics World magazi ...

Study sheds light on dark matter

Feb 06, 2006

British astronomers say they have, for the first time, determined some of the physical characteristics of dark matter.

Dilaton could affect abundance of dark matter particles

Oct 02, 2007

The amount of dark matter left over from the early universe may be less than previously believed. Research published in the open access journal PMC Physics A shows that the "relic abundance" of stable dark matter particles such a ...

Recommended for you

Quest for extraterrestrial life not over, experts say

Apr 18, 2014

The discovery of an Earth-sized planet in the "habitable" zone of a distant star, though exciting, is still a long way from pointing to the existence of extraterrestrial life, experts said Friday. ...

Continents may be a key feature of Super-Earths

Apr 18, 2014

Huge Earth-like planets that have both continents and oceans may be better at harboring extraterrestrial life than those that are water-only worlds. A new study gives hope for the possibility that many super-Earth ...

Exoplanets soon to gleam in the eye of NESSI

Apr 18, 2014

(Phys.org) —The New Mexico Exoplanet Spectroscopic Survey Instrument (NESSI) will soon get its first "taste" of exoplanets, helping astronomers decipher their chemical composition. Exoplanets are planets ...

User comments : 9

Adjust slider to filter visible comments by rank

Display comments: newest first

frajo
1 / 5 (1) Nov 02, 2009
Unfortunately the article didn't answer the important question if they found any B-mode polarization component in the CMB. This in turn would mean a gravitational wave contribution to the cold and hot spot distribution in WMAP which could be explained by inflationary models but not easily by the cyclic/ekpyrotic model. If OTH there is no B-mode component then inflationary models need further fine-tuning while the cyclic/ekpyrotic model becomes still more attractive.
RayCherry
5 / 5 (2) Nov 03, 2009
I must admit that I don't like this news, but there we go. We all have to change and adapt our ideas in line with the new data. If this really is the initial evidence for conclusive path to Dark Matter and the fifth force, Dark Energy, then I am (sincerely) happy for those scientists who have stood by this theory in the past ten years and more.

Congratulations to them, and especially to Cardiff.
frajo
2.3 / 5 (3) Nov 03, 2009
We all have to change and adapt our ideas in line with the new data.
Yes. But these new data don't answer the old questions. Where's the GUT? The hierarchy problem? Why the metaphysical (and not physical) notion of a "beginning of space and time"?

If this really is the initial evidence for conclusive path to Dark Matter and the fifth force, Dark Energy, then I am (sincerely) happy for those scientists who have stood by this theory in the past ten years and more.

DM doesn't make things easier. As yet nobody knows where it fits into particle physics.
DE neither. As yet there isn't even a GUT for the four known forces. And the SN-Ia standard candle is empirical only.

I keep waiting for a theory with elegance and beauty.
sward
not rated yet Nov 03, 2009
If you were to physically reduce the universe to the size of molecules we would observe bonds between molecules, and these would be different as per chemistry bonds. Does any one think the likeness between the infinately small universe and the infitately large universe is similar ? and share the same characteristics and rules. After all we know these chemical bonds exist because we observe them ... could this DM we seem to be observing be these bonds on a grand scale ?.
frajo
3.3 / 5 (4) Nov 03, 2009
could this DM we seem to be observing be these bonds on a grand scale ?

We do not observe DM. Instead we have discrepancies between the masses we conclude from measurements of the visible stars/galaxies and the masses we conclude from measurements of galactic rotation velocities.
In order to resolve these discrepancies, the existence of DM is postulated. Not observed.
pauldentler
3 / 5 (3) Nov 03, 2009
could this DM we seem to be observing be these bonds on a grand scale ?

We do not observe DM. Instead we have discrepancies between the masses we conclude from measurements of the visible stars/galaxies and the masses we conclude from measurements of galactic rotation velocities.
In order to resolve these discrepancies, the existence of DM is postulated. Not observed.


We do however observe the "effects" of DM, the 90% of unaccounted gravity holding the finite universe together preventing uncontrolled expansion. The source of that missing 90-95% of "matter" should more precisely be dubbed "unobserved matter", not "dark"; "unobserved matter" simply meaning "it's there, it's just that we can't see it", the terminolgy "dark matter" carries a sinister sounding implication out of the Star Wars cowboy series of science fiction movies. Everything in the universe is in "orbit" about something else much bigger than itself, the law of "conservation of energy" mandates it.
yyz
5 / 5 (1) Nov 04, 2009
A paper recently appeared entitled 'Improved measurements of the temperature and polarization of the CMB from QUaD' with several authors mentioned in the article above. Head over to: http://arxiv.org/...03v3.pdf to read about their observations and subsequent implications.

It's refreshing to see that one of our regular, knowledgeable, posters (RayCherry), can honestly express his disdain for the new results reported on in the above article but at the same time keep an open mind as to where the evidence leads, and at least give some credence (as well as a shout out to the many scientists who have pored over this problem and come to their conclusions) to where the evidence has lead. If only others posting at PhysOrg could keep their personal beliefs in check. I know, easier said than done, but I applaud RayCherry on his openess to accept new ways to thinking (within reason of course) and not to dismiss out of hand plausible alternative explanations.
frajo
1 / 5 (1) Nov 04, 2009
Thanks a lot for the arXiv link. The paper states:
A detection of B-mode polarization (on any scale) has yet to be made.

Now two quotes from Steinhardt's and Turok's book "Endless Universe" (2006):
Is there any B-mode polarization in the WMAP pattern? If so, this verifies the presence of gravitational waves and inflation alone passes the ... test.

Although the team was emphasizing the agreement with the inflationary picture, by failing to find evidence for gravitational waves, they had actually ruled out some of the most promising models.

I'm confused. The article says that the paper supports the inflationary model. Steinhardt and Turok say that "no B-mode polarization found" supports the ekpyrotic/cyclic model and
push inflationary proponents into a corner where they would have to introduce further special fine-tunings.

Anybody around to show me what I got wrong?
CyberRat
1 / 5 (1) Nov 05, 2009
Again assumptions based on made up parameters like dark matter. The story continues, years of research used to make a new 'bible' "The Big Bang".

Btw why does the image of background radiation looks similar to a plasma universe? ;)

http://www.grg.or...erse.jpg

More news stories

Easter morning delivery for space station

Space station astronauts got a special Easter treat: a cargo ship full of supplies. The shipment arrived Sunday morning via the SpaceX company's Dragon cargo capsule.

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.