Galaxy cluster Abell 85, seen by Chandra, left, and a model of the growth of cosmic structure when the Universe was 0.9 billion, 3.2 billion and 13.7 billion years old (now).  Credit:  Chandra

No “Big Rip” in our Future: Chandra Provides Insights Into Dark Energy

Article Updated: 24 Dec , 2015

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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


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Hunnter
Member
Hunnter
December 16, 2008 4:39 PM
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… Read more »
Nephish777
Member
Nephish777
December 16, 2008 5:09 PM

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.

Farcall
Guest
December 16, 2008 5:42 PM

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… sad

Jeffrey
Guest
Jeffrey
December 17, 2008 2:37 AM

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?

Silver Thread
Member
Silver Thread
December 16, 2008 8:20 PM

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.

Joe Shobe
Guest
Joe Shobe
December 16, 2008 9:12 PM
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,… Read more »
Farcall
Guest
December 17, 2008 2:10 AM

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.

Feenixx
Member
December 17, 2008 2:45 AM
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… Read more »
edunuke
Guest
edunuke
December 17, 2008 7:38 AM

“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.

Eric Near Buffalo
Guest
Eric Near Buffalo
December 17, 2008 7:52 AM

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.

Dark Gnat
Guest
Dark Gnat
December 17, 2008 8:09 AM
Huygens
Guest
Huygens
December 17, 2008 8:10 AM

The Big Rip will come the day God asks us to pull His Finger.

Jeffrey Boerst
Member
December 17, 2008 8:50 AM

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?

Feenixx
Member
December 17, 2008 8:58 AM
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… Read more »
clear
Guest
clear
December 17, 2008 9:06 AM

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.

Spoodle58
Member
December 17, 2008 9:12 AM

>>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.

Richard Kirk
Member
Richard Kirk
December 17, 2008 10:53 AM
> 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… Read more »
Shaun
Guest
Shaun
December 17, 2008 11:17 AM

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?

Feenixx
Member
December 17, 2008 11:57 AM
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… Read more »
James
Guest
James
December 17, 2008 1:35 PM

“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?

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