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When you throw a ball up into the air, you expect gravity will eventually slow the ball, and it will come back down again. But what if you threw a ball up into the air and instead of coming back down, it accelerated away from you? That’s basically what is happening with our universe: everything is accelerating away from everything else. This acceleration was discovered in 1998, and scientists believe “dark energy” is responsible, a form of repulsive gravity, and it composes a majority of the universe, about 72%. We don’t know what it is yet, but now, for the first time, astronomers have clearly seen the effects of dark energy. Using the Chandra X-ray Observatory, scientists have tracked how dark energy has stifled the growth of galaxy clusters. Combining this new data with previous studies, scientists have obtained the best clues yet about what dark energy is, confirming its existence. And there’s good news, too: the expanding Universe won’t rip itself apart.
Previous methods of dark energy research measured Type Ia supernovae. The new X-ray results provide a crucial independent test of dark energy, long sought by scientists, which depends on how gravity competes with accelerated expansion in the growth of cosmic structures.
“This result could be described as ‘arrested development of the universe’,” said Alexey Vikhlinin of the Smithsonian Astrophysical Observatory in Cambridge, Mass., who led the research. “Whatever is forcing the expansion of the universe to speed up is also forcing its development to slow down.”
Vikhlinin and his colleagues used Chandra to observe the hot gas in dozens of galaxy clusters, which are the largest collapsed objects in the universe. Some of these clusters are relatively close and others are more than halfway across the universe.
The results show the increase in mass of the galaxy clusters over time aligns with a universe dominated by dark energy. It is more difficult for objects like galaxy clusters to grow when space is stretched, as caused by dark energy. Vikhlinin and his team see this effect clearly in their data. The results are remarkably consistent with those from the distance measurements, revealing general relativity applies, as expected, on large scales.
Previously, it wasn’t known for sure if dark energy was a constant across space, with a strength that never changes with distance or time, or if it is a function of space itself and as space expands dark energy would expand and get stronger. In other words, it wasn’t known if Einstein’s theory of general relativity and his cosmological constant was correct or if the theory would have to be modified for large scales.
But the Chandra study strengthens the evidence that dark energy is the cosmological constant, and is not growing in strength with time, which would cause the Universe to eventually rip itself apart.
“Putting all of this data together gives us the strongest evidence yet that dark energy is the cosmological constant, or in other words, that ‘nothing weighs something’,” said Vikhlinin. “A lot more testing is needed, but so far Einstein’s theory is looking as good as ever.”
These results have consequences for predicting the ultimate fate of the universe. If dark energy is explained by the cosmological constant, the expansion of the universe will continue to accelerate, and everything will disappear from sight of the Milky Way and its gravitationally bound neighbor galaxy, Andromeda. This won’t happen soon, but Vikhlinin said, “Double the age of Universe from today, and you will see strong affect. An astronomer would say this may be a good time to fund cosmological research because further down the road there will be nothing to observe!”
Vikhlinin’s paper can be found here.
Source: Chandra Press Release, press conference
Almost makes me wonder how fast this acceleration will reach.
So far, it shows no signs of slowing down.
Whats going to happen if it reaches c?
Whats going to happen if it exceeds c?!
It could very well create a “physical end” to the universe, one that would probably destroy anything on contact, or trap it forever in a loop.
Or it might now, it could keep going, and we’d need to massively change our equations.
And it makes me wonder what life will do to survive the big freeze.
Could a race create artificial galaxies given enough time? Create a large barrier all the way around the galaxy that absorbs energy from outside of it, and only radiates energy if there is excess.
Maybe we could even harness the power of dark matter itself to create said galaxy.
That is, of course, if it exists and isn’t something else entirely.
T’is all a spooky mystery that i fear probably won’t be understood because of humanities stupidity and in-fighting.
Sad, i know.
Since it is space itself that is expanding (IF the “Big Bang” and the inflation theory of the “Big Bang” is correct) much of the universe is already moving a way from us faster than the speed of light. To me it appears that the laws of physics, as we understand them, is the same throught the universe.
Actually, in the “Multiverse”, all we have to do is find a way to move civilizations to them – they’re said to be always popping into existence – and, problem solved! Intelligence will be immortal!
Of course, first we have to evolve intelligence, and when I see the news, I despair of that ever happening… 🙁
Not Nancy’s best bit of writing. She seems to confuse dark matter & dark energy at times.
Why can’t dark energy be the shock wave front of inflation?
So, if we’re in an area of High Concentration and the area outside of the area we are in is an area of Low Concentration owing to it’s vacancy at creation of the universe, isn’t it the natural course of things that stuff will attempt to fill in the void even as the void continues moving away from us? I don’t really understand much of this mind you but I have often wondered if this does explain why everything is apparently moving away from where we are.
Glad to see Ms Atkinson is back – been away for a week or so? I’ve read this story told by three other science writers, and again Ms. Atkinson hits the nail on the head ..”throw a ball up in the air…” tells the whole story.
That said, there’s so much room for reasonable speculation with this story. The visual that best applies here, in my humble estimation, is filling a baloon with 4% oil, and an expansive 96% air. The film of baloon material can be considered the boundry between dark matter (the air) and regular matter (the oil) and dark energy; but this baloon has to be expansive (nearly limitlisly)and compresive, like an intestine wall.
Now, place the baloon under deep enough enough water to represent the pressure dark energy is placing on our expanding universe Could be pretty deep. The baloon will compress in areas where air and oil are coalessed into globs similar to our galaxy clusters. Where the oil separates with pockets of air would represent a galaxy or clusters of galaxies spreading ever faster apart from each other.
Dark energy is the matter into which our universe initially banged. Inflation spread the baloon broadly, but relatively flat, and dark energy is cavining in on any gaps where the air and oil have not coallessed. Hmm.
Actually, at least the way I understand it, everything is moving away from most everything else. For instance, the Local Group of galaxys may be bound together by gravity, but it you were in *any* other spot in the universe, everything would appear to be moving away from you.
It is the space *between* the galaxys that is expanding.
Very interesting, thanks for this article.
It’s been a subject of lighthearted “pseudo scientific” speculation for me for quite a while:
“If the expansion of the Universe keeps accelerating, will we be able to observe forever less of it as time passes, and keeps passing… by the billions of years?”
It looks like this little speculation may actuaqlly become real science…
….and another such speculation just occurred to me, quite a silly one, but intriguing and entertaining:
If it is true that there was an episode of “inflation” at a speed greater than the speed of light early in the history of space and time, then Goodness only knows what may be “hiding” in the portion of the Universe which has become invisible to us….
“So far, it shows no signs of slowing down.
Whats going to happen if it reaches c?
Whats going to happen if it exceeds c?!”
to Hunnter:
–> nothing can reach C for starters.
“It could very well create a “physical end” to the universe, one that would probably destroy anything on contact, or trap it forever in a loop.”
—-> No it can’t. Read more physics and less science fiction.
If galaxies are pushing away from galaxies, even in their own clusters, could it even be a product of those galaxies’ individual magnetism? For instance, their magnetisms could be pushing them apart like when you try to put the two magnets together and the polarity of one resists the other.
I’m probably way off base, but I don’t have the time or mental capacity to read all of the laws of physics and be able to understand them at the same time.
To Hunnter and edunuke
http://www.sciam.com/article.cfm?id=the-end-of-cosmology
The Big Rip will come the day God asks us to pull His Finger.
So Hunter…
That means that our whole solar system
could be, like one tiny atom in the fingernail
of some other giant being. This is too much! That means one tiny atom in my fingernail could be… Could be one little… tiny universe.
Could l buy some pot from you?
edunuke says:
“Read more physics and less science fiction.”
You write harsh words. Let me have a closer look… you say
“nothing can reach C for starters”.
That’s true, but it’s a bit like telling a child “don’t do this” and leaving it at that, resulting in a puzzled and cranky child – I’ll try and put it into a phrase that explains it a little better: “Accelerating massive objects or particles to reach c would require infinite energy – hence, if Relativity is valid, it cannot be done”
The “Big Bang” was not an explosion, resulting in bits flying off in all directions from one point. Space itself began expanding.
According to “Inflation”, an object in an expanding space can indeed recede from an observer at greater than c. See, it doesn’t need to accelerate. Space itself expands.
And then the object becomes invisible to the observer.
Even though I have read quite a lot of Physics, it gets too complicated for me from there on, but… there’s even a name for all the unusual phenomena caused by this effect: “The Horizon Problem”.
since when scientists have exchanged science for superstition?
so now every time that we fail to understand a phenomenon, well just associate some weird nick name to it hoping that should explain it…
dark matter, dark energy… whats next? dark aliens that we cant see, detect nor study are causing all the weird stuff to happen…
that’s simply us failing to justify our incompetence in physics, our academic fields need a deep cleaning.
>>edunuke
“Read more physics and less science fiction”
Their are some good ideas in Science Fiction.
A lot of physics is only theory which may as well be science fiction anyway as we know little or nothing about particular areas, the fate of our universe would be one of those areas where by we know little or nothing and no one here in the present time will ever get to say I told you so because we will not be around to witness proof.
So even Hunnter may be correct.
> Clear
“since when scientists have exchanged science for superstition?
so now every time that we fail to understand a phenomenon, well just associate some weird nick name to it hoping that should explain it…”
‘Gravity’ in Newton’s day meant the opposite of ‘levity’. It also had a sense of ‘weight’. Newton used the word to describe some invisible spooky action at a distance and theorized that this was what was keeping the moon and planets in orbit. His use of the word ‘gravity’ gave rise to some cartoons in the papers on Newton’s law of levity, har har har and so forth.
Newton’s theory works if he assumed the earth had an average specific gravity of about 6. This is a lot more than most of the stuff you find on the surface, so he had to suppose that the heavy stuff had sunk to the middle to get his theory to work.
Yep. We’ve been doing this sort of thing for some time, now.
It works, even when it doesn’t work. The ‘big rip’ theory was a big extrapolation from some rather scanty data. However, unless you publish ideas like that, then people who might come up with a disproof are not likely to do so. It seems like they have, and in doing so they have drawn our attention to the ‘arrested development’ of the universe. This in turn may get modified, but the general trend is onwards and upwards.
I have a question. If space is actually expanding, would it be possible to stop yourself from moving with the expansion?
For instance, if I grab my space ship, fly towards the moon and “stop” half way, where I am no longer making progress toward the moon and no longer receding from the earth and remain in a constant with the two, I’m essentially only stopped in relation to those and my solar system. But could I actually hit the brakes and stop, watching our solar system and galaxy drift away from me at the rate of the universe’ expansion?
Shaun asks:
“could I actually hit the brakes and stop, watching our solar system and galaxy drift away from me at the rate of the universe’ expansion”
I’ve been doing this kind of thing at college, with OTHER ssolar systems and galaxies…. by calculating the redshift.
My attempt at explaining how I see it working probably stinks a bit…. 😉
As long as you are part of our galaxy, you won’t see it drift away.
If you were watching from somewhere in the Andromeda Galaxy, you’ll see our own Galaxy APPROACHING.
See, these are movements of objects within space, relative to WHERE you are…
…..as opposed to….
the space within which the objects move, expanding, relative to WHEN was the last time you looked.
Ah, well, I tried….
“Read more physics and less science fiction”
“Nothing can reach C for starters.”
How about I read science fiction by physicists such as Benford, Baxter, and Forward? Am I then straddling the line enough to not be boxed in by preconceived notions created by our currently limited understanding of the universe?
What if ( i have no scientific basis for this, so it’s just a thought) that even though the expansion keeps on going “forever” there might still be a big crunch after all?
It may be possible, if dark energy causes a velocity(v) tangent. As matter is pushed more and more towards c you see an asymptotic curve forming in a graph. If you then also picture the universe as a globe in which our 3 dimension represent the surface of the globe, any matter passing the other side of the globe relative to the point you are standing, v would immediately negate itself, ie from 10^7 to -10^7 or 10^5 to -10^and the matter would also be coming towards you then. Dark energy would start slowing it down again, until gravity takes over and pull everything back into a big crunch.
My 2c
Reading more physics is always a good idea. But so is learning the liminations of “modern” science. I, too, like R Kirk says, have a feeling scientist are taking a “Cosmic Map”, and so to speak, are writing “Here there be monsters” each time a new unknown pops up.
Imagine reading what would pass for a physics textbook a thousand years ago. Now imagine reading one from a thousand years from now. The difference could be as greater or greater.
Dark Matter, Dark Energy, the Multiverse, clashing “Branes”, respected cosmologist speaking of alternate worlds, and mirror worlds like our own, but different. I have a hunch – oh, I know, not very scientific – but none the less a hunch we are standing on the edge of a revolution in our understanding of the universe that may dwarf everything that has gone before.
I think more people should read more science fiction. We’re going to need a lot of imagination to replace the sea serpents and “monsters” on the new Cosmic map with facts. And prepare for the possibility these new “facts” may sound like science fiction…
Thank you for this great piece of news!
Though I missed somehow one important point. You say the dark matter has features of a cosmological constant which implies that the expansion of the universe will continue to accelerate. On the other hand, at the very beginning of your article you claim that the Universe is not going to rip itself apart. Is not one of those two statements excluding the other one? It reads somehow confusing and contradictive
Last week I posted as Steve, but decided to be more creative…
Last week it was Black Holes. This week, Dark Energy. I am glad these scientists are keeping busy ‘discovering’ thing that don’t exist.
When the Standard Model fails again and we need a new force, they will contact George Lucas and ask what he would like us to call it.
I refuse to believe we live in a universe where 96% of everything is undetectable.
There is no way any of this is real. the EU theory explains all this with no mysterious and unexplained forces. EU theories are sound and based on things that can be replicated in a lab.
Hiker,
Refusing is the essence of your perception.
Ostriches refuse as well, to see what might frighten or confuse them. (I know they don’t really, just using a metaphor).
I too, thought the article lacked for layman english that would explain the difference between “creating gulfs between us and the known universe” and “the big rip”. Is it saying that gravity will keep local things together so that subatomic particles never have to worry about losing their neighbours?
Peter Says:
December 17th, 2008 at 8:59 pm
Hiker,
Refusing is the essence of your perception.
Ostriches refuse as well, to see what might frighten or confuse them. (I know they don’t really, just using a metaphor).
I too, thought the article lacked for layman english that would explain the difference between “creating gulfs between us and the known universe” and “the big rip”. Is it saying that gravity will keep local things together so that subatomic particles never have to worry about losing their neighbours?
~~~~~
The concept of the big rip boils down to the concept that eventually space would be stretched so much that the laws of physics would no longer apply and matter would start to break down. Essentially with the removal of all of the forces, noting remains to keep molecules and even atoms together and everything gets ripped apart. The difference between that and what the article describes is that we would no longer be able to see anything that isn’t local – it would still exist, but we would have no way to look at it or measure it.
I’m sorry but I see a strong contradiction between article statement: “there’s good news, too: the expanding Universe won’t rip itself apart.”
And the words of Vikhlinin :
“Double the age of Universe from today, and you will see strong affect. An astronomer would say this may be a good time to fund cosmological research because further down the road there will be nothing to observe!”
This a strong confirmation of the Big Rip scenario, then it is therefore confirmed not refuted.
Please clear it up
Hiker 9965 Says: When the Standard Model fails again and we need a new force, they will contact George Lucas and ask what he would like us to call it.
Are you implying the standard model fails?
If you ever take a class, or even watch enough lectures about particle physics, you would know that the standard model doesnt “fail”, it grows.
If String Theory was ever proven correct (a long shot), it would jst be added to the Standard Model.
If thats not what your implying, then my apologies.
Well said James
Odisea- As stated in the article, everything in the universe will move so far away from everything else that nothing will be visible. It won’t rip apart, but will just keep expanding. It won’t rip because dark energy is a constant across space, with a strength that never changes with distance or time. Since dark energy’s strength doesn’t grow over time, it won’t rip the universe apart.
I understand your explanation, you’re right. Sometimes it is not easy too understand topics about cosmology.
Keep it up your good work!
Thanks Nancy
The only reason the Standard Model does not ‘fail’ is that cosmologists keep adding patches when a new bit of information comes along that contradicts it.
When a patch can not be added, the data is swept under the carpet. Like Halton Arp’s work.
The Standard Model is also self contradictory. Like…. Nothing can go faster than the speed of light… unless of course we need it to go faster than the speed of light to patch our model.
Why are we looking for Dark Energy? Because without it the model fails. Lets stop putting patches on a dead theory and take a new, fresh look at the universe.
more jargen:
all galaxies flying away from each other. except andromida & the milkey way (and all other colliding galaxies) Dark matter/energy? Lets call it what it is-cosmological constant (unkown). Must be their for theory to be correct, its not possible we’ve error’ed
If the Universe is expanding at a faster rate,
maybe at 13.7 billion years old the universe hasn’t started to slow down yet. And will start slowing sometime in the future..
Or maybe the Universe has already stopped expanding and is now speeding up returning to the ‘beginning” of time.
Can we take from this that galaxies will become further apart from each other, but that individual galaxies themselves will remain unchanged, i.e. stars will not drift apart eventually dissipating the milky way into nothing? I’m not sure if i’ve phrased that well enough- will galaxies be undamaged, but isolated?