Record Breaking “Dark Matter Web” Structures Observed Spanning 270 Million Light Years Across

by Ian O'Neill on February 25, 2008

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The distribution of dark matter obtained from a large numerical simulation (credit: Max-Planck Institute for Astrophysics)
It is well documented that dark matter makes up the majority of the mass in our universe. The big problem comes when trying to prove dark matter really is out there. It is dark, and therefore cannot be seen. Dark matter may come in many shapes and sizes (from the massive black hole, to the tiny neutrino), but regardless of size, no light is emitted and therefore it cannot be observed directly. Astronomers have many tricks up their sleeves and are now able to indirectly observe massive black holes (by observing the gravitational, or lensing, effect on light passing by). Now, large-scale structures have been observed by analyzing how light from distant galaxies changes as it passes through the cosmic web of dark matter hundreds of millions of light years across…

Dark matter is believed to hold over 80% of the Universe’s total mass, leaving the remaining 20% for “normal” matter we know, understand and observe. Although we can observe billions of stars throughout space, this is only the tip of the iceberg for the total cosmic mass.

Using the influence of gravity on space-time as a tool, astronomers have observed halos of distant stars and galaxies, as their light is bent around invisible, but massive objects (such as black holes) between us and the distant light sources. Gravitational lensing has most famously been observed in the Hubble Space Telescope (HST) images where arcs of light from young and distant galaxies are warped around older galaxies in the foreground. This technique now has a use when indirectly observing the large-scale structure of dark matter intertwining its way between galaxies and clusters.

Astronomers from the University of British Columbia (UBC) in Canada have observed the largest structures ever seen of a web of dark matter stretching 270 million light years across, or 2000 times the size of the Milky Way. If we could see the web in the night sky, it would be eight times the area of the Moons disk.

This impressive observation was made possible by using dark matter gravity to signal its presence. Like the HST gravitational lensing, a similar method is employed. Called “weak gravitational lensing”, the method takes a portion of the sky and plots the distortion of the observed light from each distant galaxy. The results are then mapped to build a picture of the dark matter structure between us and the galaxies.

The team uses the Canada-France-Hawaii-Telescope (CFHT) for the observations and their technique has been developed over the last few years. The CFHT is a non-profit project that runs a 3.6 meter telescope on top of Mauna Kia in Hawaii.

Understanding the structure of dark matter as it stretches across the cosmos is essential for us to understand how the Universe was formed, how dark matter influences stars and galaxies, and will help us determine how the Universe will develop in the future.

This new knowledge is crucial for us to understand the history and evolution of the cosmos [...] Such a tool will also enable us to glimpse a little more of the nature of dark matter.” – Ludovic Van Waerbeke, Assistant Professor, Department of Physics and Astronomy, UBC

Source: UBC Press Release

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Hello! My name is Ian O'Neill and I've been writing for the Universe Today since December 2007. I am a solar physics doctor, but my space interests are wide-ranging. Since becoming a science writer I have been drawn to the more extreme astrophysics concepts (like black hole dynamics), high energy physics (getting excited about the LHC!) and general space colonization efforts. I am also heavily involved with the Mars Homestead project (run by the Mars Foundation), an international organization to advance our settlement concepts on Mars. I also run my own space physics blog: Astroengine.com, be sure to check it out!

Astrofiend February 25, 2008 at 5:35 PM

Jeeeez people!

Dark Matter and Dark Energy are mainly used as general and catch-all terms in astronomy. They are used to describe, in the broadest possible terms, something that exists that causes a corresponding effect.

Dark matter is the term that refers, in the broadest possible terms, to the implied cause of an observed effect. Namely, the effect that the magnitude of the gravitational force in most parts of the Universe appears to be greater than what we can account for by adding up the contributions from all of the observable matter that we know about.

Likewise, in a Universe whose expansion is apparently accelerating, our current understanding of gravity demands that there be a cause of this acceleration. The cause is termed ‘dark energy’, because it needs a name and nobody knows for sure what it might be.

Many scientists have proposed specific phenomena as being the answer to DM and DE – the theories are out there, and now we await the observations that will either cut them down or lend them credibility. But lets just remember that, in broad terms, the terms DM and DE are really just names for gaps in our current understanding… In this respect, there is nothing really wrong at all with the original article.

kservall Kimball Service February 26, 2008 at 5:47 AM

W. Scott –

Your postings are most informative and well considered. “We need to keep open minds, and explore ALL the possibilities” is so relevent in matters of cosmology. That said, I would like to acknowledge Jovica Aleksik’s reference to “Dark Matter, Dark Energy” DVD course from The Teaching Company. Yes – a bit pricey (you can get the package during one of their frequent sales) but I could not stop watching the entire course, almost at one sitting! Sean Carroll from Cal Tech did the presentation. I can not do the material justice here (or anywhere else for that matter) but the thread that I got from Dr. Carroll’s class was his openess to “ALL the possibilities” – including M-theory, string theory, and branes etc.

My copy of “DM, DE” is on loan to a friend now. I wish the public library would have a copy available for those so interested. Until then, good mentors like youself and others will continue to presnt us with “ALL possiblities.”

John Mendenhall February 26, 2008 at 6:28 AM

“W. Scott Says:
February 25th, 2008 at 12:45 pm
Dear John Mendenhall,

I submit that quantum entanglement and quantum tunnelling are evidence supporting multiple dimensions.

Spontaneous quantum eruptions of paired particles in empty space is supporting evidence of multiple dimensions.

String Theory’s consistent Quantum Theory of Gravity works where the standard model never has. Supersymmetry eliminates Quantum Theory’s open-door-policy on spectacularly absurd particles like Tachyons.

A multidimensional universe, like dark matter, is still one hypothesis, unproven, but also like dark matter, has a statistically non-random positive distribution of supporting evidence, and an absence of directly conflicting evidence. Just because one scientist uses a telescope, and another uses mathematics doesn’t mean either has the superior approach to the truth.”

You miss the point. There is no observational evidence to support more than 3 space and 1 time dimension. It is a great disappointment; we casually bandy about the idea of multiple dimensions all the time, and it becomes part of our way of thinking. But the best research finds no physical evidence of multiple dimensions. Believe me, I was shocked to find this out. The real universe cold, cruel, and simple. One, two, three, and it only moves in one direction in the fourth.

The quantum phenomena are not evidence of multiple dimensions, they are predicted as events with a non-zero probablity. The string theories, as we all know, have not yet made any testable predictions. SR and GR make and have made many, many testable predictions, using 4-space, and have passed them all with flying colors.

dave February 26, 2008 at 12:19 PM

i believe dark matter is matter not yet discovered;dark energy seems to have better explanations.

Tobias Maramba February 27, 2008 at 12:37 AM

To Jovica Aleksik,
“Neutrinos and black holes have nothing to do with dark matter.”

I don’t think you know what you’re talking about here. Dark matter is merely matter that does not emit any form of electromagnetic radiation. Because the matter in black holes does not emit light, you can say it is in fact dark matter.

alphonso richardson February 27, 2008 at 7:53 AM

Another good set of postings, Guys!
I agree with with W Scott & Astrofiend, in the sense that there seems to be some confusion as to what Dark Matter & Energy actually ARE, what scientist mean when they use these terms & what the rest of the (non)-Scienctific community mean.

What was taken as a shorthand to describe effects that couldn’t be readily explained has taken a life of it’s own beyond the original meaning, especially in a sound-bite culture

rob February 27, 2008 at 10:36 AM

very interesting talkback. i’m not smart enough to comprehend the math behind M-theory and the current debate over the existence of dark matter, but one thing seems clear: that we are at a kind of impasse. sounds like physicists and cosmologists are struggling greatly to come up with a theory that explains how the universe continues to expand, but nothing anyone’s come up with so far is testable.

the universe is keeping its mysteries for now.

it would be very interesting to me if we eventually discovered that the speed of life and force of gravity were in fact not uniform throughout the universe.

how strange and intriguing this all is to ponder. sometimes i look at the sun and can’t believe it ever even formed.

rob February 27, 2008 at 10:37 AM

i meant ‘speed of light’. a nice slip.

Jovica Aleksik February 27, 2008 at 12:50 PM

Heh, I was already trying to imagine a meaning for “speed of life” :D indeed a nice one..

About the non-testable predictions of String Theory: Let’s wait a year or so.. The Large Hadron Collider at CERN is only about to begin operation.. There might be some interesting new observations at the energy levels it will reach. Maybe there won’t be any surprises at all, but I definitely doubt that ;)

Ignoramus February 29, 2008 at 3:08 PM

Some good criticism being formulated about this article.
One wonders what individual is capable of writing something as asinine and wrong as “It is well documented that dark matter makes up the majority of the mass in our universe. The big problem comes when trying to prove dark matter really is out there” If it is so well documented why is it difficult to prove?
If “It is dark, and therefore cannot be seen” why does the title say “Dark Matter Web Structures observed”.
And this gets published!!!!

Tissa Perera March 3, 2008 at 7:14 AM

Forget about trying to find real dark matter.
My hypothesis shows how real visible matter
can mimic the so called dark matter. Read my
idea at my website:
cosmicdarkmatter.com

HolyAvengerOne March 3, 2008 at 8:06 PM

W. Scott, I lift my hat to you, sir.

While the original article left me dubious on its validity and scientific value, your replies and those of others above really got me thinking… and left me lost in their wake.

As a casual observer of the cosmological and astrophysical scene, as well as an avid reader of Universe Today, all this left me more confused than ever. And even more skeptical about the scientific interest of the articles presented herein. I’m not too sure anymore of what credibility I should attribute to UT !

Thanks (sort of, lol) ;)

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