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Missing Matter, Parallel Universes?

Soulskill posted about 2 years ago | from the cosmic-whodunnit dept.

Space 154

Phoghat writes "Could mirror universes or parallel worlds account for dark matter — the 'missing' matter in the Universe? In what seems to be mixing of science and science fiction, a new paper by a team of theoretical physicists hypothesizes the existence of mirror particles as a possible candidate for dark matter. An anomaly observed in the behavior of ordinary particles that appear to oscillate in and out of existence could be from a 'hypothetical parallel world consisting of mirror particles,' says a press release from Springer. 'Each neutron would have the ability to transition into its invisible mirror twin, and back, oscillating from one world to the other.'"

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Mirror Universe? (4, Funny)

Akido37 (1473009) | about 2 years ago | (#40376833)

And in this parallel universe, everyone has a goatee.

Re:Mirror Universe? (0)

Anonymous Coward | about 2 years ago | (#40377031)

And in this parallel universe, everyone has a goatee.

That explains it! I don't have a goatee because I'm too lazy to trim around and make one. I thought I was just "un-cool" but the real answer is that I'm from another universe.

Help me get back, please! Unfortunately, Wil Wheaton doesn't post here anymore - HE could tell me how to reverse the phase inducers to produce the proper tachyon field that would send me back to the universe of no goatees! Or get with Fargo and Henry and maybe THEY can come up with something.

Re:Mirror Universe? (0)

Anonymous Coward | about 2 years ago | (#40377133)

Or a cowboy hat.

I'm jealous. Why don't I have a hat? And why am I Foghat grey?

Re:Mirror Universe? (1)

Anonymous Coward | about 2 years ago | (#40378263)

I've got both. No wonder this place feels strange.

Re:Mirror Universe? (2, Insightful)

Caerdwyn (829058) | about 2 years ago | (#40377303)

Baryonic matter ("normal" matter from our perspective) is the minority.

WE are the Goatee Universe.

"WE are the Goatse Universe." (2)

zooblethorpe (686757) | about 2 years ago | (#40380479)

Baryonic matter ("normal" matter from our perspective) is the minority.

WE are the Goatse Universe.

NOOOOOOOoooo ... oh, wait, that's not what you said. Phew.

Re:Mirror Universe? (0)

Anonymous Coward | about 2 years ago | (#40377369)

The one day I don't have any mod points laying around...

Re:Mirror Universe? (0)

Anonymous Coward | about 2 years ago | (#40377921)

And in this parallel universe, everyone has a goatee.

And in another parallel universe everyone is a goatse.

Re:Mirror Universe? (0)

Anonymous Coward | about 2 years ago | (#40378281)

Man, I am so glad I read that twice. I don't want to go to the parallel universe where everyone has a goatse.....

Re:Mirror Universe? (0)

Anonymous Coward | about 2 years ago | (#40378369)

Or it's where coin tosses end up the opposite of what they do here.

"One year later, I got beat up at a Neil Diamond concert by a guy named Scrunchie!"

Re:Mirror Universe? (0)

Anonymous Coward | about 2 years ago | (#40379223)


Misread as goatse. would make for one twisted dark world!

Mirror, mirror (1)

stevegee58 (1179505) | about 2 years ago | (#40376853)

Home of the Evil Spock.

Mirror Mirror (0)

Anonymous Coward | about 2 years ago | (#40376907)

Anomaly of ordinary particles? Hypothetical parallel world?... c'mon! ... everybody in here knows that our evil twins exist there and kill and sabotage each other with the one goal of becoming captain of a starship.
The only way to transcend between the worlds is a modified transporter beam.
Slashdotter = unimpressed by this

What? (1)

Missing.Matter (1845576) | about 2 years ago | (#40376949)

I guess I'm my own invisible mirror twin then?

Re:What? (0)

Anonymous Coward | about 2 years ago | (#40377081)

Except that mirror Spock was actually sort of a decent fellow. Helped to reform the Terran Empire and all that.

Not parallel universes (1)

tylersoze (789256) | about 2 years ago | (#40376989)

I believe they're talking about mirror matter. It's still in this universe but doesn't really interact with anything else, kind of like, oh dark matter is suppose to. :) So rather than new particles, they're existing particles but with a reversed parity. I'm not really sure how this would account for how dark matter is distributed differently than normal matter since I would think it would pretty much clump together to form the exact same structures as normal matter would.

http://en.wikipedia.org/wiki/Mirror_matter [wikipedia.org]

Re:Not parallel universes (5, Insightful)

FrootLoops (1817694) | about 2 years ago | (#40378359)

Yes and no. Your link refers to mirror matter based only on parity symmetry while I believe the paper at hand is more general. The arXiv preprint [arxiv.org] discusses this at the start:

Concerns about parity are irrelevant for our following discussions: they extend to a parallel sector (or sectors) of any chirality. Nevertheless, in the following we shall name the twin particles from the `primed' parallel sector as mirror particles.

To set things up, imagine stepping through a mirror and doing some physics experiments. You would expect everything to work out the same as before so long as "left" and "right" were reversed (...along the axis normal to the mirror...). That turns out not to be the case, which was surprising--some decades ago a few experiments with relatively exotic particles didn't work out as expected (brief history here [wikipedia.org] ). Thus matter "through the mirror" and "before the mirror" are distinguishable. It's possible that matter through the mirror exists in our before-the-mirror universe, though it shouldn't interact much with the matter we're used to because the force-carrying particles need to be mirrored as well which ends up leaving only gravitational interactions. As you may have guessed, this is a potential candidate for dark matter. The lack of electromagnetic interactions would prevent distant mirror matter from being seen, and the lack of strong or weak interactions would nix many lab tests (like those that detect neutrinos, which are detected by their weak interactions).

My (poor) understanding of the paper is that they consider an essentially arbitrary parallel universe with wimpy interactions with our own universe (except gravitationally), not necessarily just one created by parity changes. In particular they focus on transitions of neutrons from our universe to the parallel one and use such transitions to explain an anomalous dependence on magnetic field direction in a previous experiment.

As usual, caution is the best plan. The authors call for more experiments, and I'm sure there are numerous explanations for their results that don't require (IMO) spooky transitions between parallel universes.

Re:Not parallel universes (2, Insightful)

grantspassalan (2531078) | about 2 years ago | (#40379585)

Is it possible that dark matter, dark energy, black holes and the Oort cloud don't exist at all, but are fanciful constructs that are required to explain certain observations according to currently “accepted” cosmological theories? There is a theory based upon known laws of electricity, that can explain the all observations without resorting to these esoteric constructs, which are nothing more than mathematical fiction. When the accepted picture of the universe put the Earth at the center, it also took fanciful models to account for the limited observations that were possible before telescopes were invented. When increasing technological ability made many observations and measurements of the solar system, the stars and eventually the galaxies, it was finally necessary to discard the old earth centric cosmology. In the same way, modern instruments have brought back a lot of results that are “puzzling” the scientists adhering to the present accepted view of the gravitational universe model. Interpreting these results by postulating that electricity and magnetism are the dominant forces, rather than gravity, the picture of the universe becomes much more coherent. Far out stuff like parallel universes and other exotic explanations are no longer necessary, but many PhD theses and science funding will have to be re-done. A fundamental paradigm shift of our view of the universe is necessary.

Re:Not parallel universes (1)

marcosdumay (620877) | about 2 years ago | (#40379703)

Is it possible that dark matter, dark energy, black holes and the Oort cloud don't exist at all

For dark matter and dark energy, yes, it is quite possible. But that possibility is becoming smaller near daily, with new observations. For black holes and the Oort cloud, no, and you should get more recent news.

There is a theory based upon known laws of electricity, that can explain the all observations without resorting to these esoteric constructs

No, there isn't. There is a theory pushed by some people that tries. It could even explain the rotation of galaxies, if you accept breaking several other theories that work well, but that's it. If you get a working theory someday that replaces dark energy with electricity, please tell me, I'm looking for a moto perpetual.

this shit? (0)

larry bagina (561269) | about 2 years ago | (#40377025)

If the facts don't line up with your theory, a normal person would say the facts are wrong or the theory is wrong (measurements and models, in this case). But cosmologists just invent outlandish theories and particles that can't be proven or disproven.

It's not all bad -- incorrect measurements of Neptune's mass lead to the discovery of Pluto searching for the nonexistent Planet X. I think I'll go with the incorrect measurements, again.

Re:this shit? (5, Funny)

thorist (1859732) | about 2 years ago | (#40377157)

Luckily we have more than one cosmologist, so it's not really a problem if some try new explanations (and maybe get to test them), because we have other cosmologists doing other things. Or are you going to suggest that there's only one cosmologist, going backwards and forwards through time and across the whole universe?

Re:this shit? (0)

Anonymous Coward | about 2 years ago | (#40377351)

I don't see what hair styles have to do with anything...

It's the economy... (0)

Anonymous Coward | about 2 years ago | (#40378291)

Luckily we have more than one cosmologist, so it's not really a problem if some try new explanations (and maybe get to test them), because we have other cosmologists doing other things. Or are you going to suggest that there's only one cosmologist, going backwards and forwards through time and across the whole universe?

Well we can only afford one in this economy. Be thankful we have him.

Re:this shit? (-1)

Anonymous Coward | about 2 years ago | (#40377425)

It is exactly as a religion. Nothing can be proved or disproved and it is all something that someone dreamed up.

We need to get religion out of science.


Re:this shit? (1)

History's Coming To (1059484) | about 2 years ago | (#40377813)

Science and religion (and philosophy for that matter) share many features, but the whole point of science is to protect against the incorrect or misleading statements of the others. So it's completely possible (and fairly common) for a scientist to hold religious beliefs, as long as science is practiced correctly then the religious beliefs will have zero impact on the results.

Re:this shit? (0)

Anonymous Coward | about 2 years ago | (#40378385)

That's assuming you can get to a result. Religious and anti-religious prejudices strongly control how and what scientists look for.

And assuming there are an infinite number of things to discover, and assuming we'll never discover all of them, prejudices have a very significant effect on the world science constructs.

Great Scientists (2)

grantspassalan (2531078) | about 2 years ago | (#40379761)

There were many scientists in earlier times when most people still believed in God, who did groundbreaking work in science and mathematics. There are names like Nicholas Copernicus, Sir Francis Bacon, Johannes Kepler, Galileo Galilei, René Descartes, Blaise Pascal, Isaac Newton, Robert Boyle, Michael Faraday, Gregory Mendel, William Thomson Kelvin, Max Planck and Albert Einstein. There are others that could be added to this list. It is quite clear from history, that belief in a Creator God does not preclude great scientific discovery and mathematics.

Re:Great Scientists (1)

Shavano (2541114) | about 2 years ago | (#40379985)

I think Einstein and Planck would be edge cases. The "god" each of them seemed to believe in doesn't seem to have been a personal god concerned with what human beings do.

Testability (5, Insightful)

DragonWriter (970822) | about 2 years ago | (#40377567)

If the facts don't line up with your theory, a normal person would say the facts are wrong or the theory is wrong (measurements and models, in this case). But cosmologists just invent outlandish theories and particles that can't be proven or disproven.

You mostly have that backwards. "Normal people" invent outlandish untestable explanations -- often with reference to supernatural intelligences -- for unexplained phenomena all the time, whereas the "mirror particle" hypothesis makes quite specific, testable predictions (and specific tests are recommended in the paper.)

I think I'll go with the incorrect measurements, again.

Dismissive assumptions are so much more scientific than actual testing.

Now all we have to account for (3, Interesting)

overshoot (39700) | about 2 years ago | (#40377041)

... is the observations that dark matter not only doesn't interrupt with electronic matter (except gravitationally) but also doesn't interact with itself.

Re:Now all we have to account for (0)

Anonymous Coward | about 2 years ago | (#40377789)

... is the observations that dark matter not only doesn't interrupt with electronic matter (except gravitationally) but also doesn't interact with itself.

Exactly - what a scam. When are cosmologists going to admit that the "missing" are energy?

Re:Now all we have to account for (0)

Anonymous Coward | about 2 years ago | (#40377991)

but also doesn't interact with itself.

Maybe it just doesn't want to get called crazy.

Re:Now all we have to account for (0)

Anonymous Coward | about 2 years ago | (#40379237)

but also doesn't interact with itself.

I'm betting it heard that doing that causes warts and blindness.

Re:Now all we have to account for (2)

FrootLoops (1817694) | about 2 years ago | (#40380707)

dark matter... also doesn't interact with itself.

Care to cite a source to that effect? It's a very strong statement. The paper specifically says the mirror matter interacts with itself in ways exactly analogous to regular matter:

There may exist a hidden parallel gauge sector that exactly copies the pattern of ordinary gauge sector. Then all particles: the electron e, proton p, neutron n etc., should have invisible twins: e', p', n', etc. which are sterile to our strong and electroweak interactions (SU(3) x SU(2) x U(1)) but have their own gauge interactions (SU(3)' x SU(2)' x U(1)') with exactly the same couplings.

and it also says that mirror matter is a good candidate for dark matter:

Mirror matter can be a viable candidate for dark matter

Unless you have something particularly compelling, I'm going to go with the pros on this one and call BS on your statement.

Oscillation (0)

Anonymous Coward | about 2 years ago | (#40377053)

Do they oscillate at 261Hz?

Re:Oscillation (0)

Anonymous Coward | about 2 years ago | (#40377445)

Not sure, but they do like Red Vines.

In a parallel universe this is a first post (0)

Anonymous Coward | about 2 years ago | (#40377131)

If you are reading this post not in first place, it means it has oscillated into your universe.

Dude where's my mass?! (0)

Anonymous Coward | about 2 years ago | (#40377219)

The idea of Dark Matter seems a bit fantastic to explain the observation of suns in the outer rings of the galaxy moving at the speed they apparently do. Maybe some development of alternative methodolgies at determining speed of celestial bodies?

What About Anti-Matter? (1)

sarku (2047704) | about 2 years ago | (#40377283)

Can someone with a good understanding of physics explain whether anti-matter could be a possible answer to this question?

Re:What About Anti-Matter? (1)

Qwertie (797303) | about 2 years ago | (#40380205)

Well, let's say there is a kilogram of antimatter floating through space and it hits Earth.

The antimatter is annihilated in an explosion of 180,000 Terajoules of energy. Oh, and some of Earth too.

There can't be much antimatter in the universe because it explodes on contact with any matter it touches. Given e=mc^2, one kilogram of antimatter plus one kilogram of matter equals 2c^2 = 18e16 joules of energy = 180,000 TJ.

IANAP (I am not a physicist, grain of salt etc.)

Direction of Toilets?! (0)

Anonymous Coward | about 2 years ago | (#40377409)

Really all that matters to me is the direction that toilets drain in this parallel universe. I can only believe that the water spins the wrong way, but to observe it would be science!

My own theory (0)

mark-t (151149) | about 2 years ago | (#40377431)

I have a theory on parallel universes.

And that's that if you have to invent the notion of a parallel universe to explain your own theory, then I think that there's a pretty good chance that your theory is bupkis. It's time to start over, examine the evidence that you have, and come up with a new theory.

Because when you add parallel universes into the mix, literally anything becomes instantaneously possible, and inherently not falsifiable.

For example... I can postulate that there are many multicolored dinosaurs living in my apartment... just in another universe. An utterly unfalsifiable claim, and ridiculous to even begin to argue that it is possible to objectively and scientifically study

Re:My own theory (2, Interesting)

Anonymous Coward | about 2 years ago | (#40378049)

When cosmologists talk about parallel universes, they have a very precise meaning, not Star Trek kinda parallel universes. In this case, a parallel universe is a plane of spacetime that is an actual distance away (through one of the higher dimensions in, for instance, M theory). Some particles that aren't attached firmly to our plane can travel between them (gravity is thought to be weak because of this). So if a cosmologist says that a parallel universe might be the cause of some effect, they *probably* have an idea for a mechanism, not just "They're like us, but they all have goatees!" These ideas are very difficult to test at the moment, so most of the work is theoretical, but they're not unfalsifiable in principle. This is why we do things like build bigger and bigger particle accelerators; it lets us create the conditions needed to test some of these crazier ideas.

Re:My own theory (4, Insightful)

demachina (71715) | about 2 years ago | (#40378079)

I'm guessing the people who thought relativity and quantuam mechanics were bupkis probably used similar lines of reasoning.

You might want to try reading Brian Greene's "The Elegant Universe" [amazon.com] . It a fairly approachable book on superstring theory and hidden dimensions for laymen.

The theories are very elegant and well thought out but are inherently difficult to prove since the sizes of the things that need to be seen are so small that they are currently unseeable, or energies required are so huge we can't produce them, so there is currently no way to experimentally prove the theories. The main superstring theories suggest 10, 11 or 26 dimensions of which we can actually see only four.

No one is advocating embracing superstring theory, hidden dimensions or multiverses as fact, since even their advocates know they are only theories, but neither should they be discarded as "bupkis" until they are disproved since they may be a way forward in understanding and resolving unresolved conflicts in quantum mechanics in particular. They are regrettably as difficult to disprove as they are to prove.

I'm of the opinion if smart people want to keep thinking about these things they probably should. Just because they are very hard problems doesn't mean they should be given up on. If smart people like the people that wrote this paper can figure out novel ways to test these hard problems, more power to them.

Re:My own theory (0)

Anonymous Coward | about 2 years ago | (#40378719)

You might want to try reading Brian Greene's "The Elegant Universe"

Yes, but can I buy it from another universe? One that have more than 26 dimensions?

Re:My own theory (1)

grantspassalan (2531078) | about 2 years ago | (#40380089)

Relativity and quantum mechanics has been experimentally tested. It used to be that ALL science was done by experimentation and observation. Unfortunately, nowadays cosmology is mostly mathematical modeling using powerful supercomputers. These mathematical models are getting increasingly complicated, in order to take into account many recent measurements and observations coming from modern telescopes and space probes. According to present theories, these models require esoteric, never yet discovered entities, such as dark matter and energy and black holes. It appears that present theories are based on fundamental assumptions that are evidently wrong.

Re:My own theory (2)

demachina (71715) | about 2 years ago | (#40380381)

As I recall general relativity took four years to confirm experimentally from the time it was published in 1915 until observations of a full eclipse established that space did bend around the Sun. Some of the teams involved had flawed experiments which seemed to disprove it, and Einsteins hopes for a Nobel Prize were frequenty dashed when, for example, an attempt to observe an eclipse during World War I ended when the German team was arrested in Russia for espionage.

One wonders how long it would have taken to prove general relativity if we didn't happen to have a moon just the right size to create a full eclipse of the Sun.

It wasn't until 1959 that better tests, using radio frequencies, were designed that better proved the predictions of the theory.

In the case of Superstring theory they have run in to an even tougher challenge since the things that need to be observed are the size of the Planck length [wikipedia.org] so they are impossible to observer with current technology.

In quantum mechanics there is still a dispute over a possible hidden mechanism behind quantum entanglement and "spooky action at a distance"

Re:My own theory (4, Informative)

FrootLoops (1817694) | about 2 years ago | (#40380759)

Just a minor note: Einstein won his Nobel for his work on the photoelectric effect (which ironically helped launch the quantum theory he distrusted the rest of his life), not for relativity. I'm not sure if you meant to imply that or not.

Re:My own theory (0)

Anonymous Coward | about 2 years ago | (#40378467)

You're confusing pop-culture illustrations with real science, or at least difference parallel universe theories. There are many conceptions of multiple universes. The dinosaurs living in your apartment seems to come from one of those theories which are at the edge of science and philosophy, which is to say, highly speculative.

I suspect, although IANAPP, the parallel universes theory implicated here is far more mundane and wouldn't necessarily implicate dinosaurs living in your living room.

Re:My own theory (1)

grantspassalan (2531078) | about 2 years ago | (#40379903)

There is an alternate theory that explains all observations in terms of electric and magnetic laws that are well understood and used every day here on earth. Because electric forces are so much greater than gravity, electricity gets things done much faster. This causes a great conflict with theories that try to explain how things came into being by processes that take immense amounts of time. This electrical theory CAN be tested by experiment and observations.

Particles Rotating in and out of "our" space (0)

Anonymous Coward | about 2 years ago | (#40377467)

Reminds me of the Genesis Machine http://www.amazon.com/The-Genesis-Machine-James-Hogan/dp/0743435974/ref=la_B000AQ4RKS_1_32?ie=UTF8&qid=1340144039&sr=1-32

missing matter question solved (-1)

Anonymous Coward | about 2 years ago | (#40377527)

it's a math error.
astronomy: grow some humility, admit mistakes, and move on...

Re:missing matter question solved (0)

Anonymous Coward | about 2 years ago | (#40377863)

Lemme guess, you have no substantial background in cosmology, physics or even mathematics? Clearly no one in the past 80 years has thought to double check their math and discover this error.

Occam's razor (1, Insightful)

slasho81 (455509) | about 2 years ago | (#40377617)

My keys seem to be missing. I can't find them anywhere! Could they be in a parallel universe? They could, but it's far more likely I'm just too stupid to figure out where they are.

Sure. (4, Funny)

Chrutil (732561) | about 2 years ago | (#40377651)

We read all this stuff trying to understand anything and all, and then the next paper they release will just say "Bazinga!"

Identify (0)

Anonymous Coward | about 2 years ago | (#40378125)

Time to start printing signs that read, "Planet Houston!"

Missing Matter, Parallel Universes? (1)

sumergo (2510518) | about 2 years ago | (#40378277)

Read the David Deutch books: "The Fabric of Reality" and/or "The Beginning of Infinity". Good "layman" descriptions of quantum theory and the possibility that we are indeed living in a multiverse where "our reality" intersects with many others . . .

Re:Missing Matter, Parallel Universes? (1)

Shavano (2541114) | about 2 years ago | (#40379827)

Disagree. If it interacts *at all* with what we can observe and measure it's part of our universe.

Dumb non-physicist question (1)

Moof123 (1292134) | about 2 years ago | (#40378307)

How do we know that all galaxies are made of matter, and that the universe isn't littered with some galaxies made out of antimatter? How would we be able to tell if a galaxy was made of anti-matter due to a different rounding error than occurred in our neck of the woods?

Re:Dumb non-physicist question (1)

Anonymous Coward | about 2 years ago | (#40378479)

One problem: The space between galaxies isn't empty - there is material there, mostly Hydrogen. So any anti-galaxy would, on its edges, be interacting with the normal material that is between galaxies. The matter-antimatter reaction would produce x-rays, which we don't see.

Re:Dumb non-physicist question (1)

Immerman (2627577) | about 2 years ago | (#40379351)

It seems to me we're in highly speculative territory here.

Firstly there's obviously very little matter in inter-galactic space, otherwise it would be too opaque to see galaxies billions of light years away, it's perfectly reasonable to assume any significant amount of normal matter near an anti-matter galaxy would have long-since been eliminated, so it would only be the occasional anti-atom that annihilates - in fact the vast majority of annihilation would probably occur deep in intergalactic space where the "galactic wind" of hydrogen and antihydrogen from normal and antimatter galaxies would occasionally interact. I'm unaware of any instrumentation in use that would detect such an extremely diffuse level of background x-ray emissions, feel free to educate me if they exist.

Secondly, if the imbalance *is* a local phenomena then it wouldn't be unreasonable to assume that it occurs at the galactic cluster or super-cluster level rather than between individual galaxies, which would significantly increase the "buffer zone" and drop the density of (anti-)matter wind by several orders of magnitude

And finally - our most powerful telescopes can't do much more than resolve the shape of nearby galaxies, do we really have anything that would detect the comparatively low level of x-ray emissions from the annihilation of a galactic wind against the foreground emissions of hundreds of billions of stars? Much less distinguish between such emissions and the expected x-ray sources such as black holes and neutron stars? Even for our nearest galactic neighbors I would be very surprised if the answer were yes.

Re:Dumb non-physicist question (1)

marcosdumay (620877) | about 2 years ago | (#40379843)

Yeah, things would be slightly different if you assume entire clusters are made of antimatter. There are plenty of galaxy colisions on the sky, and none of them emmit the gamma (for closer ones) or X-ray (for distant ones) radiation we'd expect.

But even with the cluster hypotesis (and assuming that earlier anihilations made enough pressure to completely separate the intergalatic matter from the intergalatic anti-matter) we'd have a problem, because there are cluster margers at the sky. Also, the simulations of the formation of the Universe give excelent results, what means that our theories proabably aren't that far off, and those results require that there is no anti-matter anywhere.

Anyway, I still thing the absense of X-ray comming from the intergalatic media is the best evidence for that. You see, the radiation shouldn't be strong enough to pressure matter and anti-matter apart; as you said, the intergalatic space is very empty. But we should be able to detect that radiation; since there isn't any difuse X-ray radiation at the sky, anything makes a difference.

Re:Dumb non-physicist question (1)

Immerman (2627577) | about 2 years ago | (#40380613)

Well, except for the fact that all our simulations require that the early universe go through a super-luminal expansion phase which we have no explanation for. Which actually introduces an additional possibility - that the matter-antimatter imbalance represents an uneven distribution in the first few moments, resulting in matter-dominated and antimatter-dominated regions which were rapidly carried so far apart that even light can't travel between them any longer.

Also, unless you know something I don't our theories don't actually require that there be no antimatter left, one of the big unanswered questions in science is actually why there (apparently) isn't. All we know for certain is that some normal matter wasn't annihilated, everything else is speculation. In fact we've yet to even experimentally confirm that antimatter interacts gravitationally with normal matter. Most theoreticians agree that it should, but without experimental evidence we just don't know - it could be that matter and antimatter are mutually repulsive, in which case collisions would be actively avoided except in the exceptionally rare cases where the stronger forces were causing an attraction. Even just a lack of interaction would make collisions exceptionally rare - space is big, the only reason pretty much anything interacts at all is because gravity causes it to clump together. Take that out of the picture and the antimatter would have just kept sailing on it's merry way while the normal matter was slowed by gravity.

From what I can tell though it's still an open question - researchers are studying colliding clusters looking for evidence of large-scale matter annihilation, without success so far, but absence of evidence yada yada. I can't find any evidence at all of a study of background gamma-ray emissions for evidence of diffuse annihilation in the intergalactic medium, and pretty much every x-ray telescope image I've ever seen features blurry "smudging" reminiscent of the CMBR in the background unless there's something extremely bright like a supernova in the foreground.

Re:Dumb non-physicist question (0)

Streetlight (1102081) | about 2 years ago | (#40378507)

If all those galaxies were made of anti-matter, then the light would be anti-light and we couldn't see them because anti-light would be invisible.

Re:Dumb non-physicist question (1)

grantspassalan (2531078) | about 2 years ago | (#40380141)

When matter and antimatter collide, the reaction products include ordinary light, usually in the x-ray spectrum. This has been experimentally verified with particle accelerators.

Re:Dumb non-physicist question (1)

FrootLoops (1817694) | about 2 years ago | (#40380801)

Not a dumb question at all. If you're actually interested in discussing this sort of thing, one place to go is PhysicsForums. Here's a thread [physicsforums.com] and paper [arxiv.org] on this topic. The general consensus is that annihilation events should be visible if a lot of the universe were made out of antimatter, but we don't seem to find any. (My very very unpolished view is that matter and antimatter were produced in slightly differing amounts for some reason during the universe's formation and the vast majority of both annihilated each other over time, leaving only a sliver of leftover, regular matter.)

Unicorn bosons (1)

WaffleMonster (969671) | about 2 years ago | (#40378935)

Sure neutrons have an aggregate charge of zilch yet quarks that make up the thing don't. We've been able to see fractional effects caused by constituents of neutrons for a while now.

It would be really interesting to understand why being able to effect a neutrons properties with a magnetic field warrants such exotic explanations.

A whole new universe? (1)

gmuslera (3436) | about 2 years ago | (#40379721)

Was just hoping that meant only just another spatial dimention or other relatively cheaper alternatives. But if we have to make guesses, lets think big from the start.

At last a testable hypthesis! (1)

Shavano (2541114) | about 2 years ago | (#40379803)

I like this because unlike most candidates for missing mass, it can be falsified. Congrats to Berezhiani and Nesti for having the balls to propose something that other scientists can measure! It should be feasible to distinguish neutrons that decay, neutrons that hypothetically oscillate into a non-interacting state and back, and those that simply escape the trap.

Strip Mining (1)

tengu1sd (797240) | about 2 years ago | (#40379923)

The Crosstime Engineers are strip mining this universe. It's close, from an energy consumption point of view and has no advanced civilization to get in the way. The testing phase is over and full scale exploitation will begin shortly.

Puzzle me this? (1)

Genda (560240) | about 2 years ago | (#40380161)

If dark matter is actually some effect of the relationship between matter in another universe and this, how is it that the two are typically linked gravitationally, but not always. If you look at this photograph recently taken by the HST [hubblesite.org] , one of the largest galaxy clusters we can see has its dark matter concentrated when the barionic matter is not. Puzzle me that? I'd have to have an explanation that would explain such anomalies.

implications (1)

Walt Dismal (534799) | about 2 years ago | (#40380229)

Would not these parallel universes be somewhat coupled, then, because moving particle positions one place could affect the other place? And obviously position could transfer energy. Would a neutron within a black hole in one universe then be able to transfer energy into or out of the black hole by means of its parallel connection? But doesn't that violate some premises of black hole physics? And finally, would evil Kirk ever be able to overcome good Kirk and absorb his acting skills?

DUH! (0)

Anonymous Coward | about 2 years ago | (#40380243)

Did you think it was some other way?

much, much, much more believable theory than that (1)

slashmydots (2189826) | about 2 years ago | (#40380687)

I have an alternative theory. How often do you see a story saying "astronomers find out ____ is actually much bigger/smaller than they thought" or "____ actually has more planets orbiting it than we thought." So they're supposed to be counting all mass in the universe AND they're using almost exclusively reflected radiation to do it?! Dark matter is a math error, if you can even call it that when the error itself is thinking you can even estimate something that complicated with our crappy technology. Creating all these theories about it are just idiotic. It's right up there with lightning....hmm, must = Zeus. Dark matter is 100% made up with almost no basis in reality.
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