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back to article BOSS Bang boffins: DARK ENERGY spreading across the Universe

New data from looking at black holes has confirmed a theory that dark energy is accelerating the expansion of the universe. The findings come from a research team that goes by the name of BOSS (Baryon Oscillation Spectroscopic Survey). Scientists have used a technique of measuring the light emitted from quasars - dying galaxies …

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Boffin

Dark Energy-

Phlogiston Proven.

Next- Aether; Where have you been hiding?

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WTF?

Re: Dark Energy-

Very easy fallacy to fall into, but giving something a name does NOT mean we understand anything at all about it. It's just that it sounds cleverer to say "73% of the universe is made of dark energy" as opposed to "we have absolutely no idea what 73% of the universe is made of except that it makes the Universe expand faster so we'll tag on the word 'energy' onto the name"

Also, this - "We know very little about dark energy but one of our ideas is that it is a property of space itself - when you have more space, you have more energy" . Is this in fact stating that "dark energy", whatever that might be, is effectively being created out of nothing, and thus is a completely different beast from the energy we know and love and which cannot be created or destroyed?

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Re: Dark Energy-

Actually, it just makes it easier to discuss and use in sentences. Try it and you will see that dark matter/energy is quite easy to use.

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IT Angle

Re: Dark Energy-

"Is this in fact stating that "dark energy", whatever that might be, is effectively being created out of nothing, and thus is a completely different beast from the energy we know and love and which cannot be created or destroyed?"

Space as we know and love cannot be created or destroyed either. And yet The Universe does exactly that at its expanding borders. Conceivably, it's quite a different environment out there. If this 'dark energy' really is a property of space ('vacuum energy' anyone? ;-), it must have been created when space came into existence.

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space

We know that spacetime is bent by gravity - we even need to account for this stuff to use GPS - so why can't it be created or destroyed?

'Out there' uses the same physics as 'down here'

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Anonymous Coward

Is it me?

Or does this sound very much like evidence based on a theory?

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Alien

Re: Is it me?

"Dark Energy" sounds very much like a theory based on sub-standard SF.

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Re: Is it me?

Welcome to how Science actually works.

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Re: Is it me?

what I want to know is how long before we've gone to PLAID?

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JDX
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Flame

It strikes me that if our theory of the universe relies on 73% of the universe being something we cannot observe or understand, it's perhaps not a very good theory.

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It's the best theory we have so far

Unless you have any better ideas that fit with the experimental observations made?

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Re: It's the best theory we have so far

How about this: our models are wrong.

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Keep IT Stupendously Simple

"It strikes me that if our theory of the universe relies on 73% of the universe being something we cannot observe or understand, it's perhaps not a very good theory." ..... JDX Posted Tuesday 13th November 2012 14:00 GMT

Cannot yet observe or understand supports the theory admirably, JDX.

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Headmaster

Re: It's the best theory we have so far

I don't know about the universe as a whole, but you don't need exotic matter, Modified Newtonian Dynamics (MOND) or "Scalar-tensor-vector gravity" to explain the observed rotation curves of galaxies. Any schoolboy with a knowledge of ordinary Newtonian gravity theory, a knowledge of computer programming and an ordinary PC can write a physics model and demonstrate the fact.

I realised this myself about a year ago and wrote a physics simulation of my own which panned out as I'd suspected. However, as I started to write up a paper on the subject (and did a better literature-search), I realised that I was by no means the first to spot the mistake: see http://arxiv.org/pdf/astro-ph/0309762.pdf for a paper by Nicholson dating from 2007. Nicholson's computer model deals with the thickness of galactic disks, mine assumed infinitesimal thickness but modelled the disk with a lot more point-masses than Nicholson did.

Regardless - we both get the same results as far as I can see. Huh: I was (at least) five years too late. No Nobel Prize for me :-(

What I can't understand is why the mainstream astrophysics community are still banging on about Dark Matter as an explanation for the "galactic rotation anomaly" when the real explanation is so simple and has been known for so long. They're not going to find any dark matter, y'know...... I strongly suspect that with Dark Matter not required to hold galaxies together, similar mistakes will be found to banish it from its other assumed purposes between galaxies.

You can't apply Newton's Theorem of Shells to disks! Isaac Newton himself knew that his theorem only applied to *spheres* of mass. Nicholson (mentioned above) wasn't even first to spot that error, but his paper is the first (that I've found) that actually reports results from computer modelling.

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" it's perhaps not a very good theory."

Or perhaps it's not a very good universe.

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Stop

Re: It's the best theory we have so far

1) We are talking Dark Energy, not Dark Matter

2) Dark Matter is pretty well established by observation and detailed computer simulation

> Any schoolboy with a knowledge of ordinary Newtonian gravity theory, a knowledge of computer programming and an ordinary PC can write a physics model and demonstrate the fact.

> You can't apply Newton's Theorem of Shells to disks!

I think therein lies the problem. You seem to assume that these simulations take short cuts of the "Computer Recreations" sort. These simulations run on large machine clusters for weeks on end and use code that is well-justified by theory, with tweaks well-justified by observation. Have a gander:

http://www.ibtimes.com/supercomputers-allow-first-detailed-milky-way-simulation-video-306976

http://en.wikipedia.org/wiki/Millennium_Run

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Megaphone

Re: It's the best theory we have so far

"How about this: our models are wrong."

About time someone said that, well done.

Sorry, but I can only give you one up vote.

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Re: It's the best theory we have so far@Destroy All Monsters

"Dark Matter is pretty well established by observation "

Well I've not seen any, and I've turned all the cushions over, and put my hand into the sofa silt. You send me a matchbox of the stuff and I'll upvote you, can't say fairer than that.

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Facepalm

Re: It's the best theory we have so far@Destroy All Monsters

> Well I've not seen any

Well, guess what, I can't send you a gravitational field either. Or show you a gluon. So maybe it's little angels pulling you down onto your sofa. Yeah. And Gremlins keeping those nuclear balls in your body in check. That's as good an explanation as any.

Really, the doofosity of the Scepticalism of the Reg Readership is amazing. Pretty sure most Scepticalists couldn't even do a simple matrix multiplication even if their last wifebeater depended on it.

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Re: It's the best theory we have so far

> "How about this: our models are wrong." About time someone said that, well done.

Babby's first illuminating thought?

Tell you what - why not go and develop your own. The whole arxiv lies open for daring publications. Have a go. Protip: Don't write in Microsoft Word.

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Holmes

Lambda

"if our theory of the universe relies on 73% of the universe being something we cannot observe or understand"

actually, no: in order to explain our observations with the theories we have, we need to introduce an arbitrary number that has the same dimension as "mass" (as in energy = mass, E=mc2) and represents 73% of the known mass (dark+normal). There can be many explanations to that, "dark energy" being only one of them. This more-or-less translates into: "we bloody don't understand what's going on, let's call it dark energy, it sounds much more professional than to justify this by some giant goat."

Another explanation is that the universe wasn't created at t=0, but was created already aged and we try to explain something that never was (anyone having programmed the game of life knows what I mean)

Another explanation is that speed of light has changed during the times, therefore the expansion of the universe is not accelerating at all.

"it's perhaps not a very good theory"

well, it works pretty well close to us, it only fails when looking far away. May-be the theory is good, but our observations are poor.

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Devil

Re: It's the best theory we have so far

"Dark Matter is pretty well established by observation and detailed computer simulation"

Eh? That isn't true at all. All we know if that certain things deviate from Relativity and that we call what causes this "dark matter". We then tweak our equations to find out what its mass must be, all the time assuming relativity is correct.

There's absolutely no observational evidence for it at all. Indeed, models have shown that it should be fairly evenly spread around our own galaxy, but absolutely no evidence for its effects can be seen in our vicinity. I don't call bullshit on it, but I think it's a bit of a long-shot.

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Stop

Re: It's the best theory we have so far

"How about this: our models are wrong."

That's odd, because they've been working and predicting things for literally decades!

*Incomplete* is the word you are looking for. If they were 'wrong' we wouldn't have managed to build all these neat toys that let us bicker from miles away.

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Re: It's the best theory we have so far

Re: Destroy All Monsters:

> 2) Dark Matter is pretty well established by observation and detailed computer simulation

Dark Matter has SO not been established by observation! That's a serious part of the problem. Even worse is the smoking gun that "Dark Matter" isn't needed to explain the rotation motion of globular clusters. You see, you *can* apply Newton's Theorem of Shells to globular clusters, and oh look, no need for dark matter.

The mistake is to use Theorem of Shells to summarise gravity behaviour in disks.

>> Any schoolboy with a knowledge of ordinary Newtonian gravity theory, a knowledge of computer programming and an ordinary PC can write a physics model and demonstrate the fact.

> I think therein lies the problem. You seem to assume that these simulations take short cuts of the "Computer Recreations" sort. These simulations run on large machine clusters for weeks on end and use code that is well-justified by theory, with tweaks well-justified by observation.

It doesn't matter what the simulations run on! If they've got their sums wrong, the results will be wrong. Large machine clusters for weeks on end or a simple PC for 10 min - it doesn't matter. Rubbish in, rubbish out.

It's your "tweaks well-justified by observation" that worries me....

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Holmes

Re: It's the best theory we have so far

"How about this: our models are wrong."

That's odd, because they've been working and predicting things for literally decades!

*Incomplete* is the word you are looking for. If they were 'wrong' we wouldn't have managed to build all these neat toys that let us bicker from miles away.

There does seem to be a habit in modern physics of inventing new stuff to keep the old theories working. As a scientist I was taught that if the evidence doesn't fit the theory, then the theory is wrong (I'll accept "incomplete"). The trend with physics these days seems to be that if the evidence doesn't fit the theory, speculate about what evidence we must be missing. It's almost a religious mindset, clinging to the Standard Model, since if if that's proven wrong then cosmologists (at least) have to start again, and many of them will have wasted their entire lives. Vested interests are as powerful in theoretical physics as they are in any other area of life.

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Re: It's the best theory we have so far

"You see, you *can* apply Newton's Theorem of Shells to globular clusters, and oh look, no need for dark matter."

Unfortunately, doing that doesn't fit with OTHER observations, like the orbits of satellites around our planet, or the orbit of our planet around the sun. So in order to make this fit the observable data, you have to start adding all sorts of arguments and 'environment variables' to Newton's laws...without any sense of what, if anything, all those new terms actually mean in the real world.

In other words, you can kludge Newton's laws to explain the observed rotational speed of galaxies, but then they break for the observed motions of smaller systems, so you have to add a whole bunch of terms of unknown real-world relevance to make it model both, and, well...it all starts to look pretty messy.

It's a lot like the "electric universe theory" in that respect. It models one currently poorly-understood system well, at the cost of abjectly failing to model systems that we already understand. And kludging it to work with both starts looking pretty arbitrary and made-up.

A model that correctly predicts the behavior of galaxies and galactic clusters but fails to predict the behavior of solar systems or galactic superclusters isn't really an improvement on what we have now.

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Mushroom

Or perhaps it's not a very good universe.

It's the best we have, lovingly blasted together by the Big Bang. But with zillions of planets, there's bound to be a few who think it's rubbish.

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Holmes

Re: It's the best theory we have so far

"There does seem to be a habit in modern physics of inventing new stuff to keep the old theories working"

Because they *mostly* still work. Just because Newtonian physics don't quite work on a galactic scale, it hasn't stopped them working for everything else.

"The trend with physics these days seems to be that if the evidence doesn't fit the theory, speculate about what evidence we must be missing."

That's only part of the story. Plenty of people are working on a swathe of alternative theories and gambling their entire intellectual career on them paying off. The problem is that very few of them even get as far as what we already have as regards actually working.

Meanwhile, the new theories that do seem to fit what we observe have already had to have large fudge-factors built in, and don't predict anything new, making them essentially rather useless.

"clinging to the Standard Model, since if if that's proven wrong then cosmologists (at least) have to start again. "

Theoretical physicists would love to have a reboot and the chance to be at the cutting edge of new ideas. Cosmologists wouldn't really have to start again, as nothing has changed what they have observed, and the old tools still *mostly* work. It's just that someone will be tapping them on the shoulder and passing them a new wrench and some fresh drill-bits.

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Re: It's the best theory we have so far@Destroy All Monsters

"I can't send you a gravitational field either"

You're wrong: You send me a matchbox, I'll bet that there's gravity inside it that I can test by putting a marble in and turning it over.

As for gluon, you physicists are just making that one up. Taking the august scientific journal that is Wikipedia, I see that it has a mass of zero, an electric charge of zero, but that it has a colour charge of octet. Who writes that stuff? Terry Pratchett?

"Really, the doofosity of the Scepticalism of the Reg Readership is amazing".

Do they extract the sense of humour from physicists by surgical means, or is it simply ejected by the sub-atomic interactions brought on by thinking too hard?

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Re: It's the best theory we have so far

Re: Franklin....

>>"You see, you *can* apply Newton's Theorem of Shells to globular clusters, and oh look, no need for dark matter."

>Unfortunately, doing that doesn't fit with OTHER observations, like the orbits of satellites around our planet, or the orbit of our planet around the sun.

Wrong way round, Franklin! Newtonian gravity fits in with all those classic observations you've listed - after all it was *derived* from them. Apparently Newtonian Gravity (with no help from "Dark Matter") explains the rotation of globular clusters too.

"Dark Matter" is deemed necessary to explain the rotation of disk-like galaxies. I call shenanigans on that and can show that Newtonian Gravity will do that job just fine too. All you've got to do is get your sums right!

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Pint

Re: It's the best theory we have so far@Destroy All Monsters

"As for gluon, you physicists are just making that one up. Taking the august scientific journal that is Wikipedia, I see that it has a mass of zero, an electric charge of zero, but that it has a colour charge of octet."

Maybe... but it *wooooorrrrrkkkks*

And that's the crucial thing. Quantum mechanics and tiny things might not actually be anything like we envisage and label them to be, because they sometimes exist outside of our perception. But for all the stupid names and ideas, it all results in a model that can explain *and predict* actual things which we can observe.

What does it matter if you label a particle's properties 'Pink Orange and Sunday'? How is that different from 'Alpha, Beta, Gamma'? So long as you can remember them and attribute characteristics to them, it doesn't make any difference.

Example: I have an electric drill at home. It has a motor in it... so I've been told. I haven't seen it, but I'm told it's called a motor. It could be called George, or Cheese. I know that if I put in current, the bit at the end goes around. So why can't I call the current 'Toast' and the resultant motion 'Snack'. So I now know that Toast+Cheese=Snack.

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Re: It's the best theory we have so far

Perhaps the full quote works better; "All models are wrong; some are useful" This is found in George Box's 1954 book. If there is an earlier citation, I have not found it but would welcome an update.

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Re: It's the best theory we have so far

Nicholson's "paper" is a pdf on arxiv. Will it ever be published or peer reviewed? It is not cited either.

Has he or have you tried to contact any active astrophysicists about their mistake? It you really have something, I'm sure they're all ears.

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Call me a sceptic

But doesn't this somehow contravene the concept of conservation. What next? A Perpetual Motion machine?

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Thumb Down

Re: Call me a sceptic

What "concept of conservation" would that be, oh illuminated one? Dontcha think someone maybe someone would have thought about it?

Really, with commentards falling all over themselves to discredit observational evidence by mentioning something they might have heard on BBC Science one day, just between brushing their teeth and playing Vidya for the night, it's a wonder Keynesians, Intelligent Designers and Antivaxers are not joining the fray.

What next indeed?

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Re: Call me a sceptic

I too was struck by the expansion is creating energy remark, which they neglect to explain - it would contravene thermodynamics.

But the view from my barely informed armchair is it could mean the Universe is expanding due to an injection of energy.

- If we take Brane theory and that gravity seems to be leaky i.e A force possibly acting over all dimensions etc. Then Dark Energy could be the gravitational effects of other Branes moving in our neighbourhood - where's my Nobel?!

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Re: Call me a sceptic

The Law of conservation of energy need not be compromised at all by this. You're talking about expansion in (at least) *four* dimensions, of which we can *directly observe* only three. You're also looking at processes that are well beyond day-to-day cares and worries, so it may well be that the law of conservation of energy is a subset of a larger set of rules that applies to the universe as a whole. Not unlike Newtonian mechanics, which work just fine as long as you don't move at relativistic speeds ( which last time I checked we're still not in a habit of doing regularly or consistently.)

I'm just as wary as the next guy of the phlogiston fallacy, but dark matter/energy as a concept plugs the hole between observed fact and theoretical model. Which is fine as long as you treat it as a blob of "we don't know yet"s instead of an actual "physical" entity.

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Re: Call me a sceptic

> it would contravene thermodynamics.

Well, most likely not. "Vacuum background energy" does not seem to be transferrable to any actual classical system. Which may be a good thing. If the vacuum is not in its lowest energy state and you start to mine it, who knows what will happen?

> A force possibly acting over all dimensions

There are just four dimensions. Anything else is ... very speculative indeed.

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Re: Call me a sceptic

'thermodynamics' has only been proven to apply to the 'normal' energy and mass that we know and understand. If we're basically positing that we know nothing about 73% of the stuff in the universe, why should we impose limits on it, especially when those limits completely contradict observed data? i.e why should we expect it to NOT contravene thermodynamics?

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Anonymous Coward

Re: Call me a sceptic

Still, it will be a depressing outcome. All the content of the entire universe, all that stuff, destined to puff away into an ever expanding oblivion. Quite glad I'll not be around to see it.

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Re: Call me a sceptic

> There are just four dimensions. Anything else is ... very speculative indeed

oh yes, theoretical physics by it's very nature is highly speculative, many theories call for more than 4 dimensions. I used parts of existing theories (M-Theory and Supergravity) to come up with my own speculative theory - I fail to see your point

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Anonymous Coward

Expansion isn't accelerating due to some mysterious energy -- time is slowing down giving the impression accelerated expansion.

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Facepalm

I'm starting to blame Hollywood!

> time is slowing down

What the hell does that even mean?

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Anonymous Coward

Re: I'm starting to blame Hollywood!

I have no time to explain it to a nincompoop. Or perhaps I have more time.

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Facepalm

Re: I'm starting to blame Hollywood!

Explain it to yourself, then. Don't fail totally while doing so.

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Mushroom

Re: I'm starting to blame Hollywood!

Its an interesting idea that's not occurred to me before: Universe expanding in all four dimensions. Certainly the idea that the speed of light has somehow changed over the eons, or that the basic electrical properties of free space may have changed has occurred to me.

Let me see - space expanding so it becomes less dense - so permittivity and permeability decrease - so EM waves speed up - or time appears to slow down.

I'm sure Mr Destroy All Monsters is about to flame me.

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Is dark energy not magic?

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So far yes, but lets not forget it's not a long time since we knew nothing about, for instance, rontgen, and science tends to start with a theory. It's also possible that we are very very far from understanding dark this or that, perhaps dark is a very good word to use for now.

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Happy

"Is dark energy not magic?"

When infrared light was first detected (with prism experiments in 1800), the notion that there could be light that we could not directly see was quite baffling to people. If I recall correctly, Herschel referred to it as "dark light."

Today, infrared light is well-understood and doesn't seem mysterious or magical to us at all, even though it seemed that way at first.

I reckon that with time, as our understanding of the physical world expands, "dark energy" and dark matter" will become better understood and will no longer seem strange or magical; indeed, referring to them by those names will sound as quaint as calling infrared light "dark light."

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Anonymous Coward

The article states "By analysing the patterns of the light they were able to create a three dimensional map showing the position of the quasars as they were when the light left them 10 billion years ago."

Interesting stuff. I have just one question, and please do correct me if I am wrong, but to determine their past 'positions' would require use of the Hubble Constant. The last time I looked there was still debate and uncertainty (although tending towards a general consensus) about past and present values. What values* have they used here?

*Plural, because the Hubble Constant is not in fact constant, but changes over time.

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