Chandra Provides Support For Dark Energy

starannihilator writes "The Chandra X-Ray Observatory has provided new evidence supporting the existence of dark energy, the force causing the acceleration of universal expansion. The new findings support the theory that the universe will expand forever, provided there is enough dark matter. CNN and Newsday are running the story, originally reported by NASA. Chandra's site has some good images and information on the three galaxies clusters studied (Abell 2029, MS2137.3-2353, and MS1137.5+6625)."

Re:Dark matters

[Mz6]

No kidding...

Why can't scientists just make up their minds already?

First it's not expanding, now it is... Oh well now it's slowing down again, and now expanding agian.

I also see no end in sight...

Re:Dark Matter

[fr2asbury]

If the universe was expanding at the speed of light. It would look pretty dark out there at night.
Or at the very least it would be awfully hard to see some of those distant galaxies.

Re:Dakr Matter

[llamaguy]

Consider for a moment that Einstein might have been wrong? Since we can't actually study anything at the speed of light properly, it's all down to the calculations and even great minds might make errors. So, you never know...

FYI for all you Hubble nuts

[Anonymous Coward]

This telescope is doing the exact same type of science that hubble is. The only difference is there is not some irration emotional attachment to this telescope and there is a much better return on investment for dollars going forward.

Re:Dark matters

[Anonymous Coward]

Seperate paths with conclusions you could make with that data put on them, ultimatly you'd want them all to be explained by a single theory. Or in other words, all the good measurements need to be accounted for. Incidentally, we know there is some dark matter out there, afterall anything that's pretty dark as in doesn't shine or doesn't reflect much light is dark matter. Just how much, well that's what they're arguing over.

Quickshot

Re:Dakr Matter

[CodeMonkey4Hire]

Hell, Newton was "wrong," but it wasn't the end of the world. In fact, the corrections to his theories led to some amazing discoveries. I would imagine that any theories that "prove" Einstein wrong will lead to some amazing technology themselves. Of course such speculation leads to... Science Fiction (I am not saying it would be wrong - remember that flying to the moon used to be scifi).

Re:Dark matters

[Too Much Noise]

It's not that simple. Cosmology is now in a position pretty much similar to that of a butterfly trying to understand the passing of seasons. Moreover, as the name says, "dark" matter/energy is undetectable directly (at least, so far) - and it's quite challenging to figure out a 'simple' theory for something that not only you can't observe directly, but the indirect observations are difficult and not always very accurate.

Anyway, since it's not very likely that the knowledge of dark matter will have a significant impact on the daily life anytime soon, relax and enjoy the (slow-moving) show.

Headline is an Exaggeration

[m1a1]

The headline to this story is an exaggeration. Of course, you can't blame it on the author seeing as the headlines of the major news sources were exaggerations as well.

So what, we have more evidence the universe is expanding at an accelerating rate. WE ALREADY KNEW THAT! This is just another indication that it's happening. This doesn't "prove" the existence of dark energy. It's still entirely possible (and I would suggest probable) that we just don't know the entire story about gravity. Physicists have gotten gravity wrong before after all.

Re:Ptolemy's back!

[FlynnMP3]

While astronomy does need another Copernicus, the times are different today. Most everything cosmologists discuss is theory these days. Only after the mathamatical models provide sufficient backing data, experiements are performed. Namely because these experiements are so costly.

I do agree all this dark matter seems like hand waving. Part of that is a lack of understanding on my part. But to be fair, even the cosmologists don't even have a handle on what they are talking about.

Re:Ptolemy's back!

[Anonymous Coward]

I think physics is overdue another Copernicus.

Feel free to step up at any time. Certainly many of us in the physics community feel likewise. And there have been many crazy ideas. Unfortunately, the experimental data rules out almost everything proposed so far.

Mark Twain once remarked: "Everyone talks about the weather but no one ever does anything about it." The same could be said for cosmological theories. Many people complain about the current system, but no one ever offers anything better.

assumption...assumption...assumption

[Anonymous Coward]

This proves nothing and provides no evidence. Read the report... everything it states about ratios and measurements involves assumptions. This isn't science. This is a bunch of people with too much time on their hands and not enough real information.

This isn't science.

unknown type of material, is POSTULATED to hold clusters together.

The observed values of the gas fraction depend on the ASSUMED distance to the cluster.

they are THOUGHT to represent a fair sample of the

ASSUMING that dark energy is responsible for the acceleration

The new Chandra results SUGGEST that the dark energy

Re:Dakr Matter

[sindarin2001]

Not only that, but I daresay there is no "correct" theory. Genius after genius creates a model that describes an ever increasingly complex universe, and then a new odd discovery throws a monkey wrench into the theory. The theory isn't really wrong, it's just no longer all-encompassing like we previously thought.

That said, sometimes a theory can be just plain wrong.

Re:Dark matters

[hazem]

Why can't scientists just make up their minds already?

Because if they did, they'd be theologians, not scientists.

Why not oscillation rather than expansion?

[Chemisor]

Why are they ignoring the obvious (at least to me) possiblity that the universe oscillates around some optimal size. Imagine the universe as a rubber ball. Squeeze the ball and let it go. Every particle inside will immediately start moving away from the others at an accelerated pace, continuing to accelerate until passing the rest boundary, when it will start slowing down. What's causing the expansion? How about the reduction of space curvature? Imagine space as a tablecloth (ok, so I'm knee deep in analogies :) on a table with a hole in the middle. Place a heavy pitcher in the middle and the tablecloth will be pulled through the hole, pulling its edges closer together. This is what happens around a star according to general relativity theory. Now, the star is constantly radiating energy and losing mass, so the space is constantly uncurving. Because it is uncurving, it is expanding. When all the stars burn out, space will start collapsing again as energy falls into black holes. Then the black holes coalesce and make the big bang singularity, which explodes for some reason and everything starts all over again.

Re:Goofy gravity

[Decaff]

If it sounds strange enough, you can probably bet there are real physicists who see it that way...

Re:Dark matters

[ArsonSmith]

I think it is common for people to make up something that helps fill gaps in science. sometimes it turns out right many times it turns out wrong. many times this happens such as space ether [tu-harburg.de].

When we can't explain something we are sometimes better off makeing something up that fills the gap until we can find the more correct answer. There is no such thing as exact science. Only reproduceable observation which eventually becomes accepted fact. Although there is no reason for it to always stay fact if someone says, "Hey, I tried to do the experiment and used this method to test it and I got a diffrent observation!" Well, now it's time to re think that scientific fact.

What happens typically is that the person is downplayed as doing something wrong, adding some new variable to the mix, or something that would throw off the observation in some way. Politics in science is as complicated and painful as anywhere.

Could we be seeing the vascilation of branes?...

[innerweb]

...I was just wondering if the expansion/contraction might not have something to do with outside forces acting upon the brane (as always, still theory) that our Universe exists in. Think of a piece of rubber sheet with a map of our cosmos on it, then think of it being stretched in different directions, around things, etc. Being stuck in a rather two dimensional viewpoint, we would see contractions and expansions over time, but the time frame may be so great that a very young society (like ours) may not really see the changes.

It may be possible to have a universe that is expanding and contracting at different times based on variables we have no ability to measure, hence never be able to know which way we are going to go, only where we seem to have gone.

For some great educational sources for the non-astro-physicist, see The Elegant Universe [pbs.org] excellent program (my six and ten year olds understood most of it). A few other articales are at Sky and Telescope [skyandtelescope.com] and Scientific American [sciam.com]

InnerWeb

Re:Dark matters

[NanoGator]

"Why can't scientists just make up their minds already?"

Because, by their very nature, they need proof?

Re:Ptolemy's back!

[pavon]

On the other hand, the decades of precise mesurements by people like Ptolemy provided the data needed to spark an idea in the mind of Copernicus. Science seems to work that way. You have a wonderful complete theory, then a long period of gathering empirical data which conflicts the theory. During this time many cludges are suggested, but real understanding does not come because there isn't enough data yet. Then you reach a point where all the pieces of the puzzle are finally available and 3 people independently discover the new complete theory.

I don't think it is a Coperinicus that the world is lacking right now, but rather understanding of the concept in general. This can only be gained by the tedious emperical work which is being done by very smart people who will likely never have the good fortune of ending up in history books simply because they were around at the wrong time.

Universal Catapult

[deathcloset]

I've always been bothered by the "the universe will expand forever, and it's accelerating" theories.

Not that I have an a fraction the knowledge or mathematical skills of these scientists; but correct me if I'm wrong.

Doesn't gravity effecct objects regardless of the distance between them? Meaning to say, that gravity, however weak, will always have this attractive force.

so, won't this energy causing this accelerating expansion eventually burn up/out?

couldn't the universe be Like the release of a stretched-out, very long rubber band (played back in slow motion). At first release starting from a velocity of 0 and then accelerating. but after expending it's energy, slowing? heck, then even retracting?

in other words, what evidence supports that this thing is going to expand at an accelerating rate forever? seems like gravity is going to get a little upset about that eventually.

Re:"Dark matter" != "Dark energy"

[Mr. Slippery]

Dark matter is normal matter.

Depends on which theory of dark matter you subscribe to. I don't think WIMPs [eclipse.net] could be considered "normal" matter.

Re:Why not oscillation rather than expansion?

[efflux]

I sure hope you have some sort of caveat on that statement... such as "a blackhole *with* an equivalent amount of mass as the sun". Otherwise the question is quite meaningless.

Re:Ptolemy's back!

[Anonymous Coward]

> Most everything cosmologists discuss is
> theory these days.

Well, yes, in the sense that EVERYTHING scientists talk about is theory. Even our descriptions of simple harmonic motion is "theory". But we are, right now, in the beginning of the era of OBSERVATIONAL cosmology - we have begun to verify theory with strongly supportive observation, via multiple methods, multiple teams, etc. No good scientist would ever claim to have the "final solution" to cosmological questions, and we all recognize that Newton (and, thus, Einstein, etc) had descriptions of reality that were CORRECT, but INCOMPLETE.

But to say that cosmologists are simply engaged in hand-waving & theorizing without any substance is to miss the point. We don't simply invent theories out of thin air - we develop them to explain good evidence, and only when evidence dictates that we must.

Re:Dark matters

[Anonymous Coward]

You mean like anthropomorphising the weather into a Sun God until you collect enough evidence to create a farmer's almanac?

Sounds like its quite a bit the opposite of science.

Re:Universal Catapult

[Anonymous Coward]

Right, gravity is always attractive and the more massive the body the stronger the gravitational attraction to it.

What the theory says is that the amount of mass in the universe is finite, and that this amount of mass is not enough to ever slow down the acceleration that is seen.

Re:Dark Matter

[wanerious]

There is no problem with space-time *coordinates* moving with respect to each other faster than c . Consider the old analogy of dots on an expanding balloon. The dots are moving away from each other, yes, but that is a result of the expansion of the *coordinates* of the balloon. The dots are not actually moving about the balloon's surface. When we say that the galaxies are expanding away from each other, it is subtle and important to realize that they are *not* moving through space, but rather that the expansion of space itself is carrying them along.

what it really comes down to is:

[amwassil]

... never was so much inferred from so little.

Re:Serves the Palestinian rabble right

[escallywag]

...God's chosen people. Palestinians are just reaping the results of working against God's will and worshipping pagan gods.

Heh, and you still wonder why people hate fundamentalist nutters like you. It's weird that fundamentalist muslims and orthodox jews are at each others' throats... You have more in common then you are different

Dark energy

[no reason to be here]

dark energy is completely unlike anything we've seen before.

Well, except that Einstein had already predicted it in his original formulation for the theory of relativity.

Re:Ptolemy's back!

[nine-times]

I know. I wasn't really disagreeing with the spirit of what the poster was saying when he said, "I think physics is overdue another Copernicus."

Copernicus is often used as an example of how a revolution of ideas can happen by only a change of perspective, a consolidation of ideas, a new way of seeing things, a return ot basics, or a simplification, and I agree physics need this. Really, science pretty much always needs this in every field.

But that last statement makes it sound too trite, so I'll be more emphatic about modern physics.[**opinions**] What seems particular about modern physics is a disregard for things that make sense- it's all about equations that come to correct values. We don't need to be talking about anything, so long as we have equations, and equations don't need to mean anything as long as they work out mathematically. So, we end up with with equations that require all sorts of exotic particles, each with 20 different types of "spin", dark matter, dark energy, 200 different dimensions, and no explanation. The physicists that come up with these theories will admit that none of this makes sense to them, and simply say "Maybe the universe doesn't make sense." Most people go along with this, but every major scientific advancement comes when someone looks at the phenomena, looks at other scientists interpretations, and says, "This is stupid! This doesn't make any sense!" and proceeds, right or wrong, to lay out an explanation that makes more sense.[/**opinions**]

So... I was only making a side comment, that Copernicus is really over-rated as an example of this kind of revolution. He entered a long-existing argument and took a side, and his great achievement was probably being more convincing and more well rememberred than others. Newton, Einstein, and the much under-rated Leibnitz are much more the real deal when it comes to genius changes in perspective. And now I've made more side comments, hopefully interesting ones.

Re:"Dark matter" != "Dark energy"

[TMB]

E=mc^2 doesn't mean that mass and energy are the same, it means that's the conversion you use when you convert between them. So if you could turn two 500nm photons into two massive particles (you can't turn a single photon into particles because of conservation of momentum), you could create two 4.4x10^-36 kg particles at rest in the center of mass frame.

It also means that photons do act as a source of gravity, with a strength equal to something with a mass of E/c^2. But in the current universe, their gravitational effect is tiny compared to the gravity of the mass... as a little exercise, try calculating the equivalent rest mass of the entire luminosity of the Milky Way and compare it to the mass of the moon. :-)

[TMB]