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Dark Matter and Dark Energy… the Same Thing?

6 Feb , 2008 by

I’ve said it many times, but it bears repeating: regular matter only accounts for 4% of the Universe. The other 96% – dark matter and dark energy – is a total mystery. Wouldn’t it be convenient if we could find a single explanation for both? Astronomers from the University of St. Andrews are ready to decrease the mysteries down to one.

Dr. HongSheng Zhao at the University of St. Andrews School of Physics and Astronomy has developed a model that shows how dark energy and dark matter are more closely linked than previously thought.

Dr Zhao points out, “Both dark matter and dark energy could be two faces of the same coin. “As astronomers gain understanding of the subtle effects of dark energy in galaxies in the future, we will solve the mystery of astronomical dark matter at the same time.”

Just a quick explainer. Dark energy was discovered in the late 1990s during a survey of distant supernova. Instead of finding evidence that the mutual gravity of all the objects in the Universe is slowing down its expansion, researchers discovered that its expansion is actually accellerating.

Dark matter was first theorized back in 1933 by Swiss astronomer Fritz Zwicky. He noted that galaxies shouldn’t be able to hold themselves together with just the regular matter we can see. There must be some additional, invisible matter surrounding the regular matter that provides the additional gravitational force to hold everything together.

And since their discoveries plenty of additional evidence for both dark energy and dark matter have been seen across the Universe.

In Dr. Zhao’s model, dark energy and dark matter the same thing that he calls a “dark fluid”. On the scale of galaxies, this fluid behaves like matter, providing a gravitational force. And in the large scales, the fluid helps drive the expansion of the Universe.

Dr. Zhao’s model is detailed enough to produce the same 3:1 ratio of dark energy to dark matter measured by cosmologists.

Of course, any theory like this only gains ground when it starts making predictions that can be tested through observation. Dr. Zhao expects the work at the Large Hadron Collider to be fruitless. If he’s right, dark matter particles will have such low energy that the collider won’t be able to generate them.

The paper was recently published in the Astrophysical Journal Letters in December 2007, and Physics Review D. 2007.

Original Source: University of St. Andrews News Release


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Guest
February 6, 2008 2:20 PM

Can we create the stuff?

Does it already exist around us, and if it does, can we measure it?

Stargeezer
Guest
Stargeezer
February 6, 2008 2:18 PM

Let’s see now. There’s got to be ‘dark energy’ and ‘dark matter’ because our theories say so. And of course our theories have always proven out to be correct. No other explanation apparently. Now if we could just do more than discover it, like maybe, actually find out what it is. Personaly, I’d be embarassed to have a ‘theory’ wherein 90% of the stuff is actually unknown. Oh well, back to our GUT theories. Maybe that new grant will come through!

Chris Paino
Guest
Chris Paino
February 6, 2008 2:37 PM

E=mc^2 works, so why not ED=md^2 ? my point being if there is a known relationship where matter and energy are known to be the same, then same is true for dark energy and dark matter. And for all those who still believe in the big bang, your are idiots. the universe is going through phase shift just like an atom does when it gains or loses energy, from say a neaby universe.

idiot
Guest
idiot
February 6, 2008 3:42 PM

I still believe in the Big Bang so I guess I’m an idiot.

Dwight
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Dwight
February 6, 2008 3:44 PM

Geez, here we go again. Another picture of some PhD standing at a blackboard… Put down the chalk and get back to real work. Even stop to think that the ‘dark’ stuff you’re looking for may actually be one of those extra-dimensions you physicists seem to have proven exist — we never know what it is but can only infer its existence by its effect on our universe. Oh how I love writing physics-babble…

idiot
Guest
idiot
February 6, 2008 3:52 PM

How i love to watch people attack physics–the most provable and disprovable science around. But I’m an idiot for believing the Universe began from a single point called the Big Bang. So let me know the real truth, you physics haters.

Superchill
Guest
Superchill
February 6, 2008 7:00 PM

I agree with Chris. If regular energy and mass are interchangeable why couldn’t the dark stuff do the same

idiot
Guest
idiot
February 6, 2008 7:15 PM

It seems to me that people who agree with someone else, are agreeing with themselves using different names…at least sometimes.

idiot
Guest
idiot
February 6, 2008 7:22 PM

I agree with idiot. DOH!

salineman
Guest
salineman
February 6, 2008 7:47 PM

“But I’m an idiot for believing the Universe began from a single point called the Big Bang.”

The Big Bang Theory, as I understand, its not an attempt to explain the origin of the universe. The Big Bang was not an explosion. It just states that the universe has been expanding from a super hot, super dense state ~13 billion years ago.

It is simply, the apparent expansion of the universe.

Saying “we came from the big bang” is therefore, in a sense, like saying “life on earth came from natural selection.”

It just bugs me when people talk about the big bang theory or the theory of natural selection in the context of origins (of the universe/life, respectably).

Jeffrey Boerst
Member
February 6, 2008 7:51 PM

Why is it that the internet is FILLED with people leaving passive/aggressive, smug, smart (bleeped) comments instead of constructive critisism, let alone anything insightful and/or intelligent?!? This covers the gamut from science sites such as this, to political, economic, computer gaming, et al…

salineman
Guest
salineman
February 6, 2008 8:05 PM

I didn’t think I was being rude, I was just making a point.

Feel free to correct me. I consider that constructive.

But about the article, it is an interesting thought. I’d like to read more about this “fluid” and how it drives expansion on the largest scales but acts as a “pull” on galactic scales. Very counterintuitive.

But isn’t it always?

VECTOR
Guest
VECTOR
February 7, 2008 3:24 AM

We searched for and rejected the idea that there is a fabric or medium, call it the aether, over a century ago.

Let’s start by dismissing the term particle as too specific to human sensory perception and instead call the collective observed phenonena – masses – instead just behaviors or functions.

Dark whatevers (mass and or energy) becomes the framework within which the observable functions operate.

Like the layers of abstraction that build up from machine language in a computer (read here dark whatevers or the medium) the observable behaviors of masss (e.g. inertial and weights) , etc. and energy become application layers on top f an operating system.

Gosh, aether is back!

N Stone
Guest
N Stone
February 6, 2008 9:01 PM

Maybe this dark stuff is a force that is kind of like antimatter and so it would accelerate things such as matter. just as matter causes friction and slows things down (decceleate), this stuff would speed things up (accelerate) things.This could also explain wormholes.

Cloy
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Cloy
February 6, 2008 10:16 PM

I’m trying to understand this as best as possible, being only in high school, but if it was antimatter and actually had the ability to lessen the friction between matter, how would it hold things together? Or does antimatter have a gravitational pull all it’s own? From what I gather from the article, this dark matter is something that can hold a galaxy together. I can see from your standpoint how it would accelerate the expansion of the universe, but I still don’t see how it would affect a galaxy. Wouldn’t the galaxy disperse if it was accelerating as fast as the universe?

Terragen
Member
Terragen
February 6, 2008 11:47 PM

Dwight, I like your point about the dark energy/matter actually being the higher dimensions. I’ve been thinking about that myself, I think we are just too small to observe them but yet all matter and energy that we see is nestled in this, whatever the stuff is!
I wonder if there is research out there on this.

Rev.
Guest
Rev.
February 7, 2008 1:03 AM

I think the suggestings made by of N. Stone are interesting concepts. Didn’t Einstein theorize the existence of something in his ToR beyond gravitional relationships of mass on mass?

Greg
Member
Greg
February 7, 2008 2:46 AM
Cosmology is a far cry from physics with regards to certainty. Of course the nature quantam mechanics still gives classical physicists headaches. Any physicist would cringe at a scientific discipline that has to invoke entities such as dark matter and dark energy to keep its theories from sinking. These concepts still seem a bit far fetched to me and I, like many others, would like to see either of these detected and measured for the first time before I am satisfied that everyone is on the right track. A little bit of reserved judgement and skepticism is always healthy. I always find it amusing how cosmologists can become absolutist when someone questions the existance of these entities which… Read more »
Bill Samson
Member
Bill Samson
February 7, 2008 4:50 AM

Unfortunately, much of the “I’m right and the rest of you are idiots” stuff comes from intuitive thinking.

It has long been known that intuition can be thoroughly misleading in physics – especially on very small or very large scales. Let’s all keep open minds on this. There’s a lot we don’t understand, and it could be some time until we do (if ever).

mike
Guest
mike
February 7, 2008 6:33 AM

I think i would have to say the some of you actually have valid points, Dwight, yes i can agree with you that this stuff might just be another higher dimension but what is it growing from?
My best guesstimate would be from everything that the black holes in our universe are eating up. I mean it has to be going somewhere right? And when this alternate universe fills up with too much matter then POOF another universe is so called born from our point of reality.

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