'Cosmic String' Gravitational Waves Could Solve Antimatter Mystery (scientificamerican.com) 80
An anonymous reader quotes a report from Scientific American: Billions of years ago, soon after the Big Bang, cosmic inflation stretched the tiny seed of our universe and transformed energy into matter. Physicists think inflation initially created the same amount of matter and antimatter, which annihilate each other on contact. But then something happened that tipped the scales in favor of matter, allowing everything we can see and touch to come into existence -- and a new study suggests that the explanation is hidden in very slight ripples in space-time. "If you just start off with an equal component of matter and antimatter, you would just end up with having nothing," because antimatter and matter have equal but opposite charge, said lead study author Jeff Dror, a postdoctoral researcher at the University of California, Berkeley, and physics researcher at Lawrence Berkeley National Laboratory. "Everything would just annihilate." Obviously, everything did not annihilate, but researchers are unsure why. The answer might involve very strange elementary particles known as neutrinos, which don't have electrical charge and can thus act as either matter or antimatter.
One idea is that about a million years after the Big Bang, the universe cooled and underwent a phase transition, an event similar to how boiling water turns liquid into gas. This phase change prompted decaying neutrinos to create more matter than antimatter by some "small, small amount," Dror said. But "there are no very simple ways -- or almost any ways -- to probe [this theory] and understand if it actually occurred in the early universe." But Dror and his team, through theoretical models and calculations, figured out a way we might be able to see this phase transition. They proposed that the change would have created extremely long and extremely thin threads of energy called "cosmic strings" that still pervade the universe. Dror and his team realized that these cosmic strings would most likely create very slight ripples in space-time called gravitational waves. Detect these gravitational waves, and we can discover whether this theory is true. The findings have been published in the journal Physical Review Letters.
One idea is that about a million years after the Big Bang, the universe cooled and underwent a phase transition, an event similar to how boiling water turns liquid into gas. This phase change prompted decaying neutrinos to create more matter than antimatter by some "small, small amount," Dror said. But "there are no very simple ways -- or almost any ways -- to probe [this theory] and understand if it actually occurred in the early universe." But Dror and his team, through theoretical models and calculations, figured out a way we might be able to see this phase transition. They proposed that the change would have created extremely long and extremely thin threads of energy called "cosmic strings" that still pervade the universe. Dror and his team realized that these cosmic strings would most likely create very slight ripples in space-time called gravitational waves. Detect these gravitational waves, and we can discover whether this theory is true. The findings have been published in the journal Physical Review Letters.
Are cosmic string observable? (Score:2)
Didn't the Enterprise once collide with a cosmic string nearly destroying it? Good times.
When they say "extremely long" what do they mean exactly?
Kling ons (Score:1)
They got roped in.
Re:Are cosmic string observable? (Score:4, Funny)
Re:Are cosmic string observable? (Score:4, Funny)
Can't I turn it into a cosmic string by sending out an inverse tachyon pulse?
Re: Are cosmic string observable? (Score:2)
Gotta reconfigure the deflector dish first. :)
Scotty would have told them it takes 24 hours. But he'll do it in 10. Scotty would also actually have done it in 4. And could have done it in 1. :)
Re: Are cosmic string observable? (Score:1)
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Shatner hates everyone and was never thrilled that his most famous role was for Star Trek.
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Would he be thrilled if his most famous role was for T.J. Hooker?
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imidan noted:
Shatner and Doohan had some kind of longstanding feud, and I've purposely avoided learning about it. Nevertheless, happy birthday, Scotty! I'm sorry about Star Trek V... that was painful for us all.
It was pretty simple, actually. Shatner was a flamiing, narcissistic assclown in the period when ST:OS was being made - and the show's success only made him more unbearable. Everyone in the cast despised him. Doohan just never bothered to hide it.
And, yeah, it's too bad he lived to make ST V: The Unabashed Clusterfuck. If only he had had the good judgement to pass away before then, he could have been spared the embarrassment of being associated with that giant, steaming pile of feces.
But, hey,
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Re:Are cosmic string observable? (Score:5, Funny)
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"And it's done what?"
Don't believe the lies! (Score:2)
It's lies, I tell you! This doesn't solve any antimatter mysteries, they are just stringing you along. ;)
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It's lies, I tell you! This doesn't solve any antimatter mysteries, they are just stringing you along. ;)
Are you saying that they are Roping us into a solution? ;)
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PLOT TWIST. (Score:2)
This doesn't solve any antimatter mysteries,
In an unexpected plot twist, it was revealed today that all matter is actually made up of ANTImatter, and that antimatter is actually the ONE TRUE matter.
Philosophers still out drinking heavily, deciding whether to just exist or to explode instead. It may take them a few more decades to debate cans vs bottles vs kegs.
That settles it then (Score:3)
There is a cat at the other end.
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Gah.... existence
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Oh, I though you were taking a stance.
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How so? [wikipedia.org]
Now who spoke *me* into existence? -- God. (Score:2)
You don't believe I'm God? :D
What happened to faith?
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Your father and mother moans *spoke* you into existence.
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It will be more informative when he's talking to Asimov himself.
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G-d was also into smiting a bunch of innocent babies and such back in the day. And skull crushing, He was big on that for awhile as well. Lately, his son Jesus was seen down at the U.S. border turning away would be immigrants.
Might I remind you of the poem on the statue of liberty, it is for what the U.S. used to stand:
Not like the brazen giant of Greek fame,
With conquering limbs astride from land to land;
Here at our sea-washed, sunset gates shall stand
A mighty woman with a torch, whose flame
Is the imprison
Re: Almost like the cosmos was spoken into existan (Score:2)
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What this website needs is a good, 5-cent banhammer ...
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A better prescription is the one on the Statue of Liberty, no mention of G-d yet it is more in keeping the spirit:
Might I remind you of the poem on the statue of liberty, it is for what the U.S. used to stand:
Not like the brazen giant of Greek fame,
With conquering limbs astride from land to land;
Here at our sea-washed, sunset gates shall stand
A mighty woman with a torch, whose flame
Is the imprisoned lightning, and her name
Mother of Exiles. From her beacon-hand
Glows world-wide welcome; her mild eyes command
T
the universe cooled? (Score:3)
"...the universe cooled..."
I hope someone can help me understand. I've read that phrase in other astrophysics theories and explanations. Here's my quandary: "universe" means everything, and if energy is conserved, how can the universe cool? Where does the heat go? Does it escape the universe? Is it somehow annihilated?
Saying the (heat) energy of the universe somehow underwent a transformation into solid matter, as in E = mc^2, would preserve conservation of energy in the universe. Is that what's happening? If so, anyone understand the process?
Re:the universe cooled? (Score:5, Informative)
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Because the universe expanded; same energy over greater area = drop in temperature.
And if we look far enough away (which is far back in time), we can see the Universe when it was hotter and denser. That's what the cosmic background radiation is: us seeing the hot dense Universe but cooled down and stretched out.
Re: the universe cooled? (Score:2)
Also, energy doesn't have to be conserved. (Score:2)
Not in all cases.
Normally yes. But there are situations where it doesn't have to. And silly things like the universe actually having no problem with "0=1-1" so you can have matter (and E=mc^2) come into existence from nothing, as long as antimatter comes into existence too.
Re:Also, energy doesn't have to be conserved. (Score:5, Interesting)
But remember, when antimatter and matter collide, pure energy is released during the annihilation, and that upsets conservation of energy.
Instead, what happens is the universe "borrows" some energy to create your matter-antimatter pair, so the energy released is what was borrowed in a galactic savings and loan. And thanks to quantum mechanics, the terms of that loan are known - the more energy is borrowed, the less time you have to pay it back - can't have excessive debt on the books for too long - the cosmic ledger much still balance. (This is all part of quantum mechanics - the whole Heisenberg Uncertainty Principle is the cause - position and velocity can be changed into energy and time)
This isn't terribly interesting, except when things happen to one member of the pair - like say, the matter particle falls into a black hole and now the universe balance sheet needs to be fixed. Which leads to the whole thing with black holes, Hawking radiation, and information destruction. And why black holes don't keep growing bigger and bigger.
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Re:Also, energy doesn't have to be conserved. (Score:4, Informative)
> But remember, when antimatter and matter collide, pure energy is released during the annihilation,
Excuse me, but what? No. "antimatter" is merely matter with opposite electrical charges to its particles. The name is confusing. It's stall a form of matter as far as energy conservation is concerned..
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Re:Also, energy doesn't have to be conserved. (Score:4, Informative)
" when antimatter and matter collide, pure energy is released during the annihilation, and that upsets conservation of energy."
This is absolutely not true, energy is conserved in these collisions. There are no challenges for the conservation law in the Standard Model. Look at dark energy, that is a concept where energy gets 'created' (negative pressure)
Antique Geekmeister said it right
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The exact shape is still a matter of debate in physical cosmology, but experimental data from various independent sources (WMAP, BOOMERanG, and Planck for example) confirm that the universe is flat with only a 0.4% margin of error.
I will not, however, take a homemade rocket and try to get high enough to p
Why was antimatter part of the Big Bang? (Score:2)
What if antimatter was not part of the Big Bang? Yes, it is produced under certain natural conditions and can be produced in a particle accelerator, but how do we know antimatter was part of the universe's inception?
Re: Why was antimatter part of the Big Bang? (Score:2)
I guess they are going for matter + equal amount of antimatter = still zero, so it "explains" how there can be something from nothing ... because all in all, in sum, there still would be "nothing". :)
But then they should really know that antimatter travels backwards in time by definition, and therefore went *the other way* at the big bang.
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Yeah, I believe I understand the problem: they want to reconcile how 50% matter + 50% antimatter resulted in all the matter we see today instead of complete annihilation of all matter. My question is: how can we assume that antimatter was involved at all?
I don't know if antimatter goes back in time - isn't it just about reversed particle charges? Still has mass. How/why is Time handled differently with antimatter?
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A positron is, in the current mathematical physics theory of quantum stuff, an electron traveling backwards in time. Remember that physics theories are written in mathematics. There's no telling whether they are 100% true to the world (Kant's Ding an Sich), we only get to determine to what percentage they accord with our observations.
Now, let's discuss aliens...no, not those bug-eye critters. I mean real aliens: cats. I predict if we ever snare one of those UFOs, we'll find cats running it.
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A positron is, [...] an electron traveling backwards in time.
Nope!
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gtall stated (in part):
A positron is, [...] an electron traveling backwards in time.
Prompting angel'o'sphere to object:
Nope!
Except that the reverse-time-traveling-electron model has not been falsified, and is still considered by some mainstream particle physicists to be a possible explanation of the existence of positrons. Just because you reject it, doesn't mean they do.
N.B. - I'm not arguing in favor of the bassackward electron hypothesis's accuracy here. I'm merely pointing out that, amongst the various hypotheses still fighting it out for the flyweight belt, it's still a contender (instead
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Except that the reverse-time-traveling-electron model has not been falsified, and is still considered by some mainstream particle physicists to be a possible explanation of the existence of positrons. Just because you reject it, doesn't mean they do.
Nope, such an idea never existed
We would never be able to "create" antimatter if that was the case, and observe it.
If no Anti-matter then no Energy Conservation (Score:2)
The problem with the latter interpretation is that in physics every symmetry has an associated conservation law. The symmetry of translation in time i.e. that I get the same result today from an experiment tha
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So either the laws of physics today are the same as they were back then and anti-matter was definitely produced just after the Big Bang in particle collisions or conservation of energy is not correct.
Or we're not getting the simulated conditions correct. It is, after all, happening in a universe that exists, already filled with regular matter and quantum foam.
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I think you have you chain of reasoning a bit mixed up here.
I completely agree that symmetry laws say that each symmetry has an assocaited conservation law. Therefore if a new symmetry is discovered it implies that a new conservation law should exist, and we can then go and look for it.
However, if does not follow from this that if the symmetry is disproved therefore the conservation law is also disproved, it might merely disprove our theory that the two are associated.
Noether's Theorem (Score:2)
However, if does not follow from this that if the symmetry is disproved therefore the conservation law is also disproved
Actually it does. Go look up what, in my opinion, is perhaps the most beautiful piece of maths: Noether's Theorem. This shows that if a system has a symmetry i.e. an operation which leaves it unchanged - i.e. a symmetry - then there is a related quantity whose derivative with respect to time is zero i.e. it does not change with time. If the symmetry does not exist then this derivative is not zero and hence the quantity will change with time. Thus if the symmetry does not exist then neither does the conserv
It is not a mystery! (Score:4, Funny)
Antimatter, by quantum physics definition, is matter that moves backwards through time.
Now guess where the antimatter from the big bang went...
Yes, obviously in the other direction in time!
And hey, maybe we are the anti-matter to them! :)
So obviously the only anti-
matter we see today, is some matter that changed direction in our future. Aka matter that will be "annihilated" in the future. Clearly a rare event.
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Does that mean if we see a big wave of it coming we know time is running out?
Duck and cover !
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This is moderated funny... but there's an actual theory that there is only one electron/positron and just keeps bouncing back and forth between the ends of the universe.
https://en.wikipedia.org/wiki/... [wikipedia.org]
Doesn't have to be just one electron. (Score:2)
And I wasn't being funny either.
I guess every sufficiently advanced science is indistinguishable from a joke...
Even when it is very very very established science (standard model of quantum physics), but that bit of it, that people usually have a blind spot at because they don't want to accept it.
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And hey, maybe we are the anti-matter to them! :)
That could be but we could know because of parity violation.
https://www2.lbl.gov/abc/wallc... [lbl.gov]
Uuum, aren't there anti-neutrinos? (Score:2)
Wanna bet there are anti-neutrinos, but since there is no property left to distinguish them from "normal" neutrinos, they are the same?
I've never heard the statement that neutrinos don't have a counter-part, and I don't think that is established science.
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Wanna bet there are anti-neutrinos, but since there is no property left to distinguish them from "normal" neutrinos, they are the same?
That's a very intriguing concept - indeed, I was surprised nobody had explored this idea before. Your comment spurred me to embark on an extended scientific study of the problem. After more than five seconds of extenuating intellectual effort I actually discovered antineutrinos, hidden deep in the secret article on neutrinos on Wikipedia [wikipedia.org]!
Re:Uuum, aren't there anti-neutrinos? (Score:4, Informative)
Anti-neutrinos are a thing and they are distinct from regular neutrinos. In usual beta decay (like the decay of a free neutron to a proton, electron and anti-neutrino) the "neutrino" created is an anti-neutrino. This ensures that the total lepton number in the process is conserved (one lepton and one anti-lepton created). I'm too tired to look up any better reference but beta decay on Wikipedia is a start (https://en.wikipedia.org/wiki/Beta_decay).
No - we do not actually know this! (Score:5, Interesting)
What we do know is that there are two spin-states of a neutrino. We call these left-handed and right-handed (clockwise and anti-clockwise as viewed from the direction of travel is a simplified way of looking at it). The particles we call neutrinos are all left-handed and the particles we call anti-neutrinos are righthanded.
This leads to two possibilities: the right-handed particle (i.e. the one we call an anti-neutrino) could be a completely different particle to the neutrino. This type of neutrino is called a Dirac neutrino and it is what is in the Standard Model. However, it is also possible that the thing we call anti-neutrino is just the right-handed spin state of the same neutrino particle i.e. there is only one particle but two possible spin-states. This type of neutrino is known as a Majorana neutrino.
The Majorana case is not ruled out by any experiment (yet!). However, if neutrinos are Majorana particles then something called neutrino-less double beta decay is possible. This decay is being actively searched for in deep, underground experiments like SNO+ [queensu.ca] and, if we can probe with sufficient sensitivity then depending on how the neutrino masses as arranged we may be able to rule out Majorana neutrinos. Confirming them is a bit harder since a positive decay signal may be due to their Majorana nature or it may be different, lepton-number violating physics...but either way it would be new physics and very exciting!
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Dang, guess I haven't been paying attention and didn't know that the status of neutrinos as Majorana particles was enough of a possibility that people were looking for it. Thanks for the correction. To it's credit, the Wikipedia article on beta decay does at the very end have a short mention of neutrino-less beta decay.
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Wanna bet there are anti-neutrinos, but since there is no property left to distinguish them from "normal" neutrinos, they are the same?
Anti neutrons are made from anti quarks. Easy to google and it leads you directly to the relevant wikipedia article: https://en.wikipedia.org/wiki/... [wikipedia.org]
Connection with String Theory (Score:5, Interesting)
The connection between the sub-nuclear strings studied in String Theory, and the cosmic strings such as those in this study, has been pointed out by Ed Copeland and Paul Saffin:
"For a long time the main connection between Strings and Cosmic Strings is that they were both much studied but never observed"
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"For a long time the main connection between Strings and Cosmic Strings is that they were both much studied but never observed"
False! I have personally seen cosmic strings on several episodes of Star Trek TNG as well as Voyager.
Ya know ... (Score:2)
But then something happened that tipped the scales in favor of matter, ...
The people living in the anti-matter universe(s) see things the other way around. Anti-matter is matter and vice-versa ...
When you start with a wrong assumption.... (Score:3)
Why?
Serious question... why would it have to have been exactly the same amount? I won't dispute the probability of each was identical, but if you flip even a perfectly balanced coin a million times, I can all but garantee that you won't get half a million heads and half a million tails exactly. It will be close, of course, but there will a difference.
And if you flip it a billion times, the difference between the heads and tails is likelyt o be even greater (it may be in the other direction, even, but it is unlikely to be any smalleer than the difference that you had with a smaller number of flips).
And if you flip it a trillion times you have an even larger difference, and so on. Don't believe me? Do a simulation. Graph the results. While the ratio of heads to tails approaches 1 as the number of cases grows, the absolute difference between the number of heads and tails slowly tends to infinity like a very slow rising log function.
It seems to me that it's entirely possible that the matter we have in the universe is just the left-over stuff from a completely unimaginably much larger (but still finite) amount of matter and antimatter that was created in the aftermath of the big bang that just didn't happen to be exactly equal, even though the chance of each was the same.
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We know gravity causes matter to clump, perhaps antimatter has anti-gravity properties. I believe the verdict is still out on this.
Furthermore, a third type of matter besides matte
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Dark matter isn't really any kind of matter at all. The naming of it as such is only an artifact of where it would otherwise go in a gravitational model.
Further, by definition, dark matter only interacts with itself or anything else in the universe through gravity. If it affected the rate at which matter and antimatter would react with eachother, because gravity itself does not have that property, then what might otherwise be called dark matter would have some non-gravitational interaction with matter w
It didn't annihilate (Score:2)
Matter/Anti-Matter problem (Score:1)