If you stare into the abyss, then the abyss will stare right back at you.
Something's missing in our universe: Boffins look into the SUPERVOID
The biggest structure in the Universe has astro-boffins a-twitter because there's less stuff in it than there should be. If you pop over to the Monthly Notices of the Royal Astronomical Society you'll find the snappily-titled Detection of a supervoid aligned with the cold spot of the cosmic microwave background, which explains …
COMMENTS
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Wednesday 22nd April 2015 10:57 GMT Bunbury
How are they defining the coldness?
So this is a region containing galaxies, albeit that they seem less densely populated than elsewhere. Galaxies have shiny hot bits. So when they say it's colder than elsewhere, do they mean there are less hot bits so on average it's colder? Or are they referring to the spaces between the galaxies?
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Wednesday 22nd April 2015 09:24 GMT Panicnow
Er, Red Shift not just velocity then?
"That's what links the supervoid to the possible acceleration of the universe's expansion: over the 1.8 billion years between ingress and egress, the universe around the photons became less dense, leaving less stuff to give the photons back their kinetic energy."
Photons loss energy as they travel it seems, i.e. they Red shift?
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Wednesday 22nd April 2015 11:55 GMT Anonymous Coward
Re: Is it just me...
Yes, because dark matter is known to form haloes around galaxies, and dark energy drives cosmic expansion. The aether was a supposedly steady state field that provided a medium for the EM wave to propagate in, whereas dark matter doesn't feel the EM force at all.
Quite different.
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Wednesday 22nd April 2015 10:40 GMT tony2heads
Catch up
Radio astronomers (Larry Rudnick, Shea Brown and Liliya Williams) saw this in a lower number of radio sources there back in 2007. It is just that now the infrared astronomers have confirmed the void.
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Wednesday 22nd April 2015 10:44 GMT Anonymous Coward
Does there have to be a reason for it?
Can't it just be the random outcome of the Big Bang? I don't understand why cosmologists assume that everything must have been smooth and even at the moment of the Big Bang. Since we don't even know what caused the BB that assumption is based on guesswork, not physics.
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Wednesday 22nd April 2015 11:51 GMT Anonymous Coward
Re: Does there have to be a reason for it?
Seems to me "quantum" is just a physics code word for "something happened but we have no idea how".
I suggest you read this (it's free) written by one of the early quantum physicists. It's very out of date but it will explain the history of quantum physics almost as it emerged, and it will show you just how wrong you are. Then you can read the Feynman lectures.
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Wednesday 22nd April 2015 16:26 GMT Anonymous Coward
Re: Does there have to be a reason for it?
"Quantum theory explains WHAT can happen. It does not explain HOW"
I repeat; read Hoffman's book and a few others. I don't think you quite understand what science does and how it works. Of course at one level of explanation we don't know why we live in a quantised universe. But we do understand to a considerable degree why classical mechanics doesn't work at atomic scales (the UV catastrophe for a start) and how uncertainty and quantisation explain many phenomena - such as how the electron can orbit an atom without spinning into it in a small blast of radiation. In essence, these are the axioms on which we build a working physical model of the world which is very precise indeed. And everything in that model has to be intellectually consistent to fit in. Therefore, suggesting that physicists simply handwave and say "quantum" when anything unexpected happens is just nonsense.
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Thursday 23rd April 2015 08:31 GMT Anonymous Coward
Re: Does there have to be a reason for it?
"I don't think you quite understand what science does and how it works"
Thanks for the assessment, but I did a chemistry degree so I have a pretty good idea.
"Of course at one level of explanation we don't know why we live in a quantised universe"
Which is just paraphrasing my point really. Quantum phenomena have to be accepted as just-is. There is currently no explanation for why or how they occur.
"Therefore, suggesting that physicists simply handwave and say "quantum" when anything unexpected happens is just nonsense."
In the context of Causes of the Big Bang theories, handwaving speculation and chucking around the word "quantum" is exactly what happens.
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Thursday 23rd April 2015 08:49 GMT Anonymous Coward
"but I did a chemistry degree so I have a pretty good idea"
I think therein lies your problem. Chemistry is at bottom the science of the behaviour of electrons that orbit atoms. It isn't really concerned with the more metaphysical questions that arise in fundamental physics.
One of my supervisors, a metallurgist, was of the view that it was a mistake for scientists to study metaphysics and the philosophical issues raised by quantum mechanics. He felt that asking too many questions along that line would stop someone being an effective working scientist. I do have sympathy with this viewpoint, because clearly if (in my case) you were investigating surface absorbtion of hydrogen in transition metal alloys, spending a lot of time thinking "When you get right down to it, what is an electron?", or "what exactly is the nature of experimentation and the status of theories?", wouldn't help. But since I ceased actual research, I've had time to investigate the more theoretical stuff and try to understand the grounding of physics. It turns out we have constructed a very effective model of the world based on a set of axioms which we are having trouble pushing down to a deeper level of explanation. But that goes for maths too.
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Thursday 23rd April 2015 13:08 GMT Anonymous Coward
Re: "but I did a chemistry degree so I have a pretty good idea"
"I think therein lies your problem. Chemistry is at bottom the science of the behaviour of electrons that orbit atoms. It isn't really concerned with the more metaphysical questions that arise in fundamental physics."
One minute you're talking about the scientific method, next your handwaving about metaphysics. Goalposts moved, much? Oh, and if you're going to try and be patronising - try harder.
"based on a set of axioms which we are having trouble pushing down to a deeper level of explanation"
Which again is paraphrasing my point. For someone who claims to be so smart you do seem to have an awful lot of trouble understanding simple statements.
I imagine you have to be very careful walking down stairs in case you trip over that massive ego you're clearly carrying in front of you.
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Friday 24th April 2015 16:16 GMT Michael Wojcik
Re: Does there have to be a reason for it?
Quantum phenomena have to be accepted as just-is. There is currently no explanation for why or how they occur.
Epistemological rubbish. Any "explanation for why or how" of any physical phenomenon is simply an appeal to a theory at another level of abstraction. This is farcically represented by the "purity argument", but as Anderson pointed out back in '72, there are unavoidable information-losing consequences in making such transitions.
Complaining that quantum theories (QED, QCD, whatever) do not answer "how" and "why" questions is simply a complaint that there is no commonly-accepted definition of a lower level of abstraction. And that's because the quantum theories as a body typically define their domain as going all the way down. There are no more turtles; you're at the last one.
If you want to make a meaningful argument that quantum physics lacks a "why or how", you're either going to have to define that next abstraction (to your interlocutors' satisfaction), or argue that we should operate under a different epistemological model. And good luck with that.
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Wednesday 22nd April 2015 11:24 GMT Primus Secundus Tertius
Re: Does there have to be a reason for it?
@boltar
Yes.
The very early universe went through an "inflationary" phase, when everything was smoothed out: the geometry, and the distribution of photons and other particles.
The reported temperature deviation is about four standard deviations, so is worth investigating.
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Wednesday 22nd April 2015 11:41 GMT Anonymous Coward
Re: Does there have to be a reason for it?
"The very early universe went through an "inflationary" phase, when everything was smoothed out: the geometry, and the distribution of photons and other particles."
Since the theory of inflation isn't looking as sure these days as it once was, using as a predictor perhaps isn't the best approach.
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Wednesday 22nd April 2015 12:04 GMT David Pollard
I don't understand this at all
"The low mass helps explain the low observed temperature of the cold spot. Crossing the region, CMB photons lose energy ... Were the universe regular, those photons would recover energy from other mass exiting the region; the shortage of mass means the energy isn't recovered."
Imagine a photon traveling from afar and crossing a region of the universe where the density is different from the average. If this was a region where density is locally higher than average, the photon's energy would increase as it approaches and then decrease back towards its original energy as it moves back into the overall average density; as it 'climbs out' of the gravitational well. So why don't photons approaching a region of lower density lose energy as they approach and then gain it back again when they move away; as in going over a gravitational hillock?
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Wednesday 22nd April 2015 14:55 GMT David Pollard
Yes, but
Suppose there happened to be massive objects situated such that through gravitational lensing there were two (or more) paths available from wherever the photon started out in the distant past to a detector on Earth, one going through the less dense region the other(s) not. Depending on the path that the photon took, its energy would be different when it arrived.
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Wednesday 22nd April 2015 13:40 GMT Wilseus
What's a cold spot not?
A hot spot!
Seriously though, I was reading in other articles that the distance to this void is approximately 3 billion light years, yet as this article states, it's 1.8 billion light years across. With this in mind, I can't understand why it appears so small in the 360 degree image, I'd expect it to take up about half the sky!
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Wednesday 22nd April 2015 15:15 GMT Anonymous Coward
That's actually the spot where the Universe's first intelligent life evolved, but many of the Galaxies were wiped out when their civilisation destroyed itself in a war. Hence the void. In a few milling years someone will be looking at the Local Group and saying "Shouldn't there have been a few more galaxies there?"
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Wednesday 22nd April 2015 19:01 GMT Cynic_999
Is it really surprising?
Throw a handful of rice onto a worktop, and you will most likely see several "holes" in the pattern where the grains are far less dense than in surrounding areas, as well as "bumps" where a small area is more densely populated. IIUC it would be an anomaly if such patterns did *not* occur in a random distribution.
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Wednesday 22nd April 2015 19:29 GMT Mark 85
Since what we see from earth is a mix of the history of the universe as far as time goes... the light we see from something 2 million light years away left there 2 million years ago... I'm puzzled by this. As they look deeper into space and find things like this void.. that's how it was, not how it is. Right? Can they extrapolate what "was" to what "is"? I'm trying to make some sense of this... A void 1.x billion light-years across means what they're seeing is a younger version on the farside than the nearside (to us). So..... what does it really all mean?
Hmm..... I guess that's why I'm not an astronomer or a quantum theory type.
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Thursday 23rd April 2015 08:22 GMT Sweep
"the light we see from something 2 million light years away left there 2 million years ago"
not quite! That would only be true if the universe was static. It isn't. Your something is 2 million light years away. The light leaves on its way to us but will take more than 2 million years to reach us as the fabric of the universe itself is expanding as the light is travelling...headfuck, right?
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Thursday 23rd April 2015 00:13 GMT John Brown (no body)
And there was me...
...expecting a story about boffins finally discovering why mobile phone signal propagation doesn't match up to the marketing hype.
So, it's a cold spot, not a hot spot and definitely not a nor spot. Although based on the details in the story it's not so much a cold spot as a very slightly more freezing humongous blemish than the normally fookin' freezing temperatures found in "average" spatial voids.