That's an interesting idea but I think any changes in Dark Energy or Dark Matter would be gradual and continuous; you wouldn't be able to measure them. I think there's an issue of size involved as well as a correlation between gravity and DM & DE; by that I mean you aren't going to measure a change in DM or DE unless you measure a change in gravity, which seems like it would be the same thing as detecting gravitational waves. It also doesn't seem like you can detect Dark Matter or Dark Energy without the help of Gravity on a very large scale. Though I'll admit I'm not up to speed on the most recent DE and DM theories.

Somehow the energy/mass content of the universe must be contained for entropy to occur. Without such containment, mass conversion to energy will be quickly expunged & galaxies cannot form, therefore the universe must be contained inside a "cosmic domain".

"Cosmic domain" thus is not descriptive of an "infinite flat universe", but a universe functioning as a giant pressure containment vessel radiating heat from warmer bodies to cooler bodies for the generation of entropy & thus motion, like the "big bang" & expansion of the universe.

Cosmic domain walls composed of combinations of DM & DE would have an intrinsic gravitational pull which would be countervailing to all galactic gravity thus preventing the universe from collapsing in on itself. If gravity of DM & DE cosmic domain walls exceeds that of all the galaxies, the universe will expand until maximum entropy is reached, as it must.

It's based on the idea that shortly after the Big Band,

Nothing important to contribute here, just laughed at how musical the universe must be, to have been created by a Big Band.

Actually, there is no indication that the author was attempting to propose that the universe was created by the Big Band, but merely that, presumably after the first performance of the Big Band, random energy fields were present. This Big Band performance may have been accompaniment for the creation of the universe - have you thought of that? The random energy fields are easily understood as the concert attendees wandering randomly, looking for the exit so they could go home. See, it is all understood simply and clearly!

It's based on the idea that shortly after the Big Band,

Nothing important to contribute here, just laughed at how musical the universe must be, to have been created by a Big Band.

The Big Band?

That would be Eru Iluvatar and his Ainur (with Melkor on harmonics).

It's based on the idea that shortly after the Big Band,

Nothing important to contribute here, just laughed at how musical the universe must be, to have been created by a Big Band.

And so it is, measure for measure.

Even if it is a poetic flight to interpret the universe in such a way, I suppose it can't be entirely ruled out.

Comforting, in a way, isn't it?

The idea is interesting. However it seems quite unlikely that we'd cross a domain wall within the timeframe of such an experiment (or they are a lot more abundant than I've last read)

Isaac Asimov once wrote me that the Tired Light theory had been discounted because it can't be proven in a laboratory. But these days, proof in a lab doesn't seem to be a criteria for giving credence to theories any more. And I still can't wrap my brain around the 'Big Bang' theory, either. a) it cannot be proved in a lab; and, b) it flies in the face of the most basic of physics principles: that energy can neither be created nor destroyed; i.e., you can't get something from nothing. It also puts the notion of Black Holes to the test; if everything we can perceive were in one infinitesimal point, the gravity would be so immense that nothing would have enough energy to go 'Bang'!

Maybe someone should revisit the tired light experiments with modern timing and measurement systems, bounce a laser off the moon to increase the distance travelled... gotta be a better use of taxpayer funds than endless theorising about 'the darkness'.

Stable topological defects of light (pseudo)scalar fields can contribute to the Universe's dark energy and dark matter. Currently, the combination of gravitational and cosmological constraints provides the best limits on such a possibility. We take an example of domain walls generated by an axionlike field with a coupling to the spins of standard-model particles and show that, if the galactic environment contains a network of such walls, terrestrial experiments aimed at the detection of wall-crossing events are realistic….

This seems to be a complicate and difficult to matter for most people (except the professional) in viewing for understanding what the dark energy/matter is and how to find it. Maybe this alternate simple scientific explanation could help to visualize the matter.
http://www.vacuum...14〈=en

".......,and dark energy – the mysterious force believed to be responsible for the accelerating expansion of the universe."

Again and again, the cosmos isn't expanding. It is only sky objects to spread away in accelerating way.

That energy isn't dark & mysterious at all. Sometime in the future, we will get there are two kinds of energy acting in mighty cosmos.

Dark matter? It is just a cosmic atmosphere of the Universe. It is an extremely small particle of compressed atom structure matters.

Since we already see the galaxies distributed along the walls and edges of the "soap bubbles", I always suspected that, early in the universe's history, the decay of some very high energy particle pushed away the matter to the "walls of the soap bubbles"; of course, it could be localized inflation.

However,
"As Benni states:
"Cosmic domain walls composed of combinations of DM & DE would have an intrinsic gravitational pull which would be countervailing to all galactic gravity thus preventing the universe from collapsing in on itself. If gravity of DM & DE cosmic domain walls exceeds that of all the galaxies, the universe will expand until maximum entropy is reached, as it must.

I would then draw the conclusion that "the gravity of DM & DE cosmic domain walls" is what drew the galaxies to the walls and edges of the "soap bubbles",

The real scientists are grasping at straws. The cosmic walls idea is a structural hypothesis without offering much insight, if any, into the mysteries of Dark Matter and Dark Energy.

And of course when real scientists are grasping at straws, the cranks come out of the woodwork to 'explain' their certainties.

Why do so many cranks - people who both are certain they know the answers and despise peer review - hang around a non-crank site? There's a mystery nearly as profound as DM and DE.

The idea is interesting. However it seems quite unlikely that we'd cross a domain wall within the timeframe of such an experiment (or they are a lot more abundant than I've last read)

Jeez I don't know - an international team of physics researchers thinks it is perhaps likely, as they describe in their paper published in Physical Review Letters, so maybe they know something you don't?

"a theory that many currently consider far outside of the domain of mainstream science."

The reason why it is considered unlikely is mostly because WMAP has excluded such artifacts of the early universe:

"Cosmological inflation has the important effect of smoothing out inhomogeneities, anisotropies and the curvature of space. This pushes the universe into a very simple state, in which it is completely dominated by the inflaton field, the source of the cosmological constant, and the only significant inhomogeneities are the tiny quantum fluctuations in the inflaton. Inflation also dilutes exotic heavy particles, such as the magnetic monopoles predicted by many extensions to the Standard Model of particle physics. If the universe was only hot enough to form such particles before a period of inflation, they would not be observed in nature, as they would be so rare that it is quite likely that there are none in the observable universe."

[cont] "Together, these effects are called the inflationary "no-hair theorem"[9] by analogy with the no hair theorem for black holes."

[ http://en.wikiped...smology) ]

I.e. pretty much what brt said.

@Benni: Entropy is a process in all systems, also non-isolated, by statistical physics. On the scale of cosmologies, FRW universes behaves as systems with exact zero energy, i.e. closed. This is explicit under inflation and the far future, as in both cases expansion is adiabatic (no energy exchange).

@Argiod: We do experiments, in this case it is the whole universe that is doing it, and observe what happens. The Standard Cosmology is tested in such "a lab".

GR doesn't preserve energy over non-local scales, or we wouldn't see redshift, decreased photon energy. But it _is_ preserved over cosmological scales, see my response to Benni above.

The real scientists are grasping at straws. The cosmic walls idea is a structural hypothesis without offering much insight, if any, into the mysteries of Dark Matter and Dark Energy.

And of course when real scientists are grasping at straws, the cranks come out of the woodwork to 'explain' their certainties.

Why do so many cranks - people who both are certain they know the answers and despise peer review - hang around a non-crank site? There's a mystery nearly as profound as DM and DE.

It's even worse because for as many cranks as there are, there are an equal number of morons who think that any proposed theory/hypothesis is correct because it is provided by one of those physicists grasping at straws. I guess the world is becoming more and more polarized on every topic; or it's just the nature of the internet.

@vm, natello, rubbersman: Nonsense all, see eg Standard Cosmology.

@yash: We know since about a century that the universe is expanding, alternative physics has all been rejected.

No one knows what DM is yet, except for its DM properties.

@ Urqelt: Read the article again, this isn't mainstream.

I'm not a big fan of theory of "cosmic domain walls which are colliding with Earth", particularly because the cosmic domains are preferably separated with fibers not branes and these fibers are moving together with galaxies - so there is very low opportunity, some measurable wall could pass the solar system. A much more probable situation will be, the Earth will pass through some dark matter cloud inside of galaxy, preferably through galactic plane.

"The doppler effect isn't debatable. The universe is expanding."

"The doppler effect"; YES! It is indubitable!
"The universe is expanding"; NO!!! So sorry about that!!!

It is that the celestial objects in cosmos travel relating to their doppler effect measurement (redshift/blueshift).

The space expanding was a translation of almost sky objects redshift, whilst friends couldn't interpret that as moving objects. This misconception urgently needs to be reevaluated.

I am aware almost all of you, legitimate professionals in this field, will veto this.
But believe me; This will be filed for future era! Many thanks to "Phys.org."

"@yash: We know since about a century that the universe is expanding, alternative physics has all been rejected."

@Torbjorn_Larsson_OM, Thank you. I appreciate that.

But, please forget all alternative theories before 2010. I am not talking about those all. I am talking of "Cloud & rain model" as a real model of Universe structure.

@Torbjorn_Larsson_OM. I trust all cosmological observations till today. I just debate current most acceptable: translations, interpretations & theories to those observations.

Oh look, another bs "theory" worked out upside-down.
The only funnier thing on this site than promoting fairy tales is the "rating system" for comments. You can give little stars to posters. (S)he loves me, (s)he loves me not... Then if someone rates my post highly, should I return the favor? Mimicking the buddy system aka "peer review"... Truly a sociological phenomenon of the gorillas herd type. Here's a big banana for a big banana.

But what a sicko you have to be to make a grading system for even them comments. It's lab Nazi control-freaks at their best: thinking science is about democracy, when it isn't. Worse yet, they indoctrinate kids into it.

In the meantime, on planet Earth: "How Wineland & Haroche Stole My Discovery (and got 2012 PHYSICS NOBEL PRIZE for it...)" https://sites.goo...ci#Nobel

Oh look, another bs "theory" worked out upside-down.
The only funnier thing on this site than promoting fairy tales is the "rating system" for comments. You can give little stars to posters. (S)he loves me, (s)he loves me not... Then if someone rates my post highly, should I return the favor? Mimicking the buddy system aka "peer review"... Truly a sociological phenomenon of the gorillas herd type. Here's a big banana for a big banana.

But what a sicko you have to be to make a grading system for even them comments. It's lab Nazi control-freaks at their best: thinking science is about democracy, when it isn't. Worse yet, they indoctrinate kids into it.

In the meantime, on planet Earth: "How Wineland & Haroche Stole My Discovery (and got 2012 PHYSICS NOBEL PRIZE for it...)" https://sites.goo...ci#Nobel

You are, without a doubt, the biggest whack job of all.

The idea is interesting. However it seems quite unlikely that we'd cross a domain wall within the timeframe of such an experiment (or they are a lot more abundant than I've last read)

I think it's a bit premature to even worry about this. They haven't even done the experiment yet. Once they do it, if there are any significant results, then we can worry about interpreting them.

As for the likelyhood of us passing through a domain wall: As I understand this version of the alternative theory, if it is correct then we should be very likely to be sitting on or near a domain wall. As I understand it, the structure of the Universe in this theory leaves matter concentrated along the domain wall intersections.

I'm not a big fan of proposing a theory and then setting out to do the observations. Proper science should start with observations and then propose theories that fit the data. In this case, they don't even have data yet, but they have a press release? Hmmmm.

As I understand it, the structure of the Universe in this theory leaves matter concentrated along the domain wall intersections.

I was sort of under the impression that the domain walls will be in the intergalactic space (i.e. the gravity that reigns in one domain intereres with the space in another domain via gravity - which is one alternative explanation for what DM is)..or the domain walls are the boundaries of separate universes (and I'd think the boundaries would hold very little matter)

Proper science should start with observations and then propose theories that fit the data.

Well, as DM is an observation I'd think the experiment would fit the bill.

In any case: it's a cheap experiment to set up - so why not run it.

Oh look, another bs "theory" worked out upside-down.
The only funnier thing on this site than promoting fairy tales is the "rating system" for comments. You can give little stars to posters. (S)he loves me, (s)he loves me not... Mimicking the buddy system aka "peer review"... Truly a sociological phenomenon of the gorillas herd type. Here's a big banana for a big banana.

But what a sicko you have to be to make a grading system for even them comments. It's lab Nazi control-freaks at their best: thinking science is about democracy, when it isn't. Worse yet, they indoctrinate kids into it.

In the meantime, on planet Earth: "How Wineland & Haroche Stole My Discovery (and got 2012 PHYSICS NOBEL PRIZE for it...)" https://sites.goo...ci#Nobel

You are, without a doubt, the biggest whack job of all.

Said an anonymous jerkoff capable of writing of himself only:
First Name: brt
Last Name: et
Username: brt

Ha! Love this Zoo. More!

Proper science should start with observations and then propose theories that fit the data.

Well, as DM is an observation I'd think the experiment would fit the bill. In any case: it's a cheap experiment to set up - so why not run it.

Cheaper yet would be to drill a whole in your scull to see if there's any hope. Let's do it!

Oh wait, let's do it upside-down according to your ingenious instructions: the drill's handle in first! That's cheapest. Plus fastest result.

What a Monty Python gallery visits here.

@rubberman, thank you.

Let's consider this:

"For several years, physicists have searched in vain for an explanation of dark matter – the invisible "stuff" that makes up what is believed to be approximately 86 percent of all matter, and dark energy – the mysterious force believed to be responsible for the accelerating expansion of the universe."

"Car model" is firstly derived base on "pattern equality fact & pattern stability fact of nature". Considering the above paragraph, almost all sky objects redshift & using the above 2 nature's facts, I got first expectation of Universe structure: The Universe has nucleus, and galaxies (while persistently leaving Universe nucleus) grow. By ageing, the galaxies will be condensed getting more compact. Then when they get too dense, galaxies will fleet back to Universe nucleus. Of course at this step, the model is yet immature.

I have to say; "Thank you Fleetfoot," regardless he denied my proposal of "Car model". By debates on "http://phys.org

By debates on "http://phys.org/n...n.html," I got the clue of Car model's cosmological figure, although my comments on above article still need many significant improvements.

Later on, I found high redshift sky objects (z>5) having tendency to correlate with the area around Ursa Major & Leo. I expect this area is the post of Universe nucleus hiding.

So, "Car model" expects:
-Dark matters (fleeting at extremely high speed) fill the cosmos as cosmic atmosphere that are responsible to cause low redshift sky objects (z around<1.2) to spread away leaving Universe nucleus. Huge amounts of DM keep intruding galaxies. Major amount of them become source of feeding black-holes growth & new stars construction in galaxies, while minor amount of them breaks becoming CMBR.
-High redshift sky objects (z around>1.4) fleet back toward Universe nucleus due to gravity becoming stronger than dragging force of dark matter wall (cosmic atmosphere).

@Benni: Entropy is a process in all systems, also non-isolated, by statistical physics. On the scale of cosmologies, FRW universes behaves as systems with exact zero energy, i.e. closed. This is explicit under inflation and the far future, as in both cases expansion is adiabatic (no energy exchange).

You need to undertake some courses in Thermodynamics, take a final exam, and get a passing grade. I've done all this which is why I understand "entropy" & you obviously do not as evidenced your haphazard paraphrasing of the language of my profession.

@Benni: Entropy is a process in all systems, also non-isolated, by statistical physics. On the scale of cosmologies, FRW universes behaves as systems with exact zero energy, i.e. closed. This is explicit under inflation and the far future, as in both cases expansion is adiabatic (no energy exchange).

You need to undertake some courses in Thermodynamics, take a final exam, and get a passing grade. I've done all this which is why I understand "entropy" & you obviously do not as evidenced your haphazard paraphrasing of the language of my profession.

And you should have taken one or two courses in addition to thermodynamics. Rudimentary mechanics would tell you that he it entirely correct, and you are not thinking beyond very basic heat transfer.

That's the trouble with a person learning one thing, they try to make everything fit that one thing. Sorta like the Plasma Man. When they only think they know that one thing, it's no longer a problem, it's entertainment.

You need to undertake some courses in Thermodynamics, take a final exam, and get a passing grade. I've done all this which is why I understand "entropy" & you obviously do not as evidenced your haphazard paraphrasing of the language of my profession.

And you should have taken one or two courses in addition to thermodynamics. Rudimentary mechanics would tell you that he it entirely correct, and you are not thinking beyond very basic heat transfer.

Six years of Engineering School education in Electrical/Nuclear Engineering has been serving me pretty well. In addition to the first two semesters of Thermo, I took special application Thermodynamics to learn water cooled nuclear reactor design (heat transfer). I know very well how to do this, as well as write fluently in English.

I did a bit more reading on the subject so that I could discuss this a bit more. There isn't much around the web because observations over the past 20 years have prety much ruled out most of the early proposals involving cosmic domain walls. Here's one of the better source I was able to find:

http://en.wikiped...l_defect

Most of the talk still going on regarding domain walls is coming from people still holding onto some variation of String Theory. Even if the experiment above is able to get any kind of meaningful result, it wouldn't be conclusive. Actually the opposite is true also. Even if they don't get any results, that doesn't really tell us much either.