My idea on what happened to all the antimatter.

[derek.basler]

I have recently been reading Moment of Creation by James Trefil, and I have stumbled upon the question, where has all the antimatter gone? I asked myself, what if micro black holes produced by the tremendous energy at the big bang are the answer? If you have an understanding in hawking radiation then you know particle-antiparticle pairs are produced at balck holes. What if, by chance, antiparticles were absorbed by these micro black holes more than regular particles. It could explain why there is more matter than antimatter. Has this been dissproved by anyone? Is this a plausible theory?

 

[LURCH]

I have to admit; that's a new one on me. Not completely ridiculous, especially since the emmitted particle from Hawking radiation is always matter (or positive energy), never antimatter. On the surface, I can't see any glaring flaw, but let's see what other PFer's have to say.

 

[derek.basler]

I would like to know if there is perhaps any possible mathematics available to back this statement in anyway or even dissprove it. It seems to make sense to me.I'm only a Junior in high school so I don't have the necessary math skills or anything like that, just an idea.

 

[Arch2008]

http://en.wikipedia.org/wiki/Baryogenesis
Well, Derek, this is a rather complex version of how antimatter got the short end of the stick, so to speak. The quick version of the explanation is that there was an asymmetry between decaying boson-anti boson pairs that left something like one part of matter for every billion boson pairs that annihilated (I’ve got a book with the exact figure that I can post later). This happened about 10^-32 seconds after the Big Bang.
In Hawking radiation, a virtual particle falls into a black hole and the other particle gains enough energy to become “real”.
http://en.wikipedia.org/wiki/Hawking_radiation

At this point in the early universe however, all the virtual particles and antiparticles were real because of the energy level created by the separation of the Super Force. So, if an antiparticle fell into a black hole, it would not create a real particle by this action. Thus, for your explanation to work, you must describe how more of the antimatter fell into the black holes than matter.

 

[derek.basler]

Ok that sounds good. Thank you for your insight! However, like previously posted, does Hawking Radiation "prefer" antimatter or matter? But also, it could occur by chance. It could have just been chance that caused more anti-matter to fall in than matter.

 

[mathman]

Ok that sounds good. Thank you for your insight! However, like previously posted, does Hawking Radiation "prefer" antimatter or matter? But also, it could occur by chance. It could have just been chance that caused more anti-matter to fall in than matter.

Looking at on a large scale, the chance occurence could not account for the existence of matter.

 

[Arch2008]

As a gross oversimplification of Hawking Radiation, the virtual particle falling into a black hole causes the black hole to lose the energy that creates the real particle. So whether this was a particle or an antiparticle that fell in, the overall effect was that the BH lost energy. Thus, the particle that fell in had the effect of “negative energy” and the other particle gets created from positive energy and so becomes “real” matter.
(The actual process is more involved but uses quantum tunneling and is less intuitive.)

The high energy levels before 10^-32 seconds after the Big Bang created X bosons and anti-X bosons. One hundred million of these X boson pairs instantly decay into one hundred million quarks and leptons, but only 99,999,999 anti-quarks and anti-leptons! So as this happened, the matter in the universe ballooned up to about 10^50 tons. At 10^-32 seconds the energy level had dropped to the point that no more X boson pairs were created. This asymmetry is what accounts for all the matter in the universe and evidence for it is found in what is called Charge-Parity (CP) violation.
http://en.wikipedia.org/wiki/CP-violation

So there is really no need for reliance on chance.

 

[derek.basler]

So does this mean that this theory may have some sort of credibility?

 

[Arch2008]

The scientific method is really pretty brutal, because what we are looking for is the truth. That said, there are about 10^95 nuclear particles that make up the matter in the universe, each made of several quarks or leptons. You propose that at a strictly 50-50 chance ratio, each time the antiparticle fell in instead of the particle. So the odds of this happening would be one divided by the product of two multiplied by the total number of particles, or 1/(2*10^95), which is approximately: 0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000005% chance of happening naturally.
I think that most people would consider this as not very credible. However, don’t be disheartened, Edison supposedly said “I haven’t failed I just discovered ten thousand things that don’t work.”

 

[derek.basler]

hahaha alright I understand that. I recently emailed a professor from University of Chicago and he showed me a paper that I could read, entitled Matter-antimatter accounting, thermodynamics, and black-hole radiation, so I guess I will read that and see where I can go from there. Thanks for your input!

 

[LURCH]

I don't think that is true, about the 50/50 chance. The part of the VPP that falls into the BH is always the antiparticle.

Don't get me wrong, I am still pretty sure this is not the correct explanation for the predominance of matter, but the part about antimatter falling into micro-BH's is credible. Even the idea that these micro-BH's would have existed in abundance in the early universe is a fairly safe bet, along with the idea that they would evaporate quickly and release normal matter as they did so.

Still probably not the right explanation, but nto bad speculating.

 

[derek.basler]

What states that it is always the antiparticle? I didn't know that it was always the antiparticle. Thats pretty interesting.

 

[cristo]

I don't think that is true, about the 50/50 chance. The part of the VPP that falls into the BH is always the antiparticle.

This isn't true. What is true is that the particle that falls into the black hole is always the particle with 'negative energy,' but nothing states that this particle must be the antiparticle. Antiparticles and particles are emitted via Hawking radiation with equal probability.

 

[Arch2008]

Remember, this is the early universe where the virtual particles were real due to the energy released by the separation of the Superforce, so the BH's don't need to radiate anything to absorb these particles. The premise is that all of the antimatter fell into the BH’s and none of the 10^50 tons of matter. That is where the 50-50 chance comes from. This really has nothing to do with Hawking radiation, its strictly 10^95 coin tosses coming up antimatter and no matter every time.
Also, there is still no oservational evidence of Primordial BH's.

 

[derek.basler]

what do you mean by negative energy?

 

[cristo]

Remember, this is the early universe where the virtual particles were real due to the energy released by the separation of the Superforce, so the BH's don't need to radiate anything to absorb these particles. The premise is that all of the antimatter fell into the BH’s and none of the 10^50 tons of matter. That is where the 50-50 chance comes from. This really has nothing to do with Hawking radiation, its strictly 10^95 coin tosses coming up antimatter and no matter every time.
Also, there is still no oservational evidence of Primordial BH's.

This doesn't seem to be the argument proposed in the OP, though. Surely if one suggests that *all* the antimatter fell into black holes, then we should have a hell of a lot of PBHs knocking around!

 

[derek.basler]

I'm saying that more antimatter may have fell into black holes than regular matter. Is this feasible?

 

[Arch2008]

Cristo, there were basically three questions that Derek posed: where has all the antimatter gone; what if micro black holes produced by the tremendous energy at the big bang are the answer; and what if, by chance, antiparticles were absorbed by these micro black holes more than regular particles? I replied that the antimatter was asymmetrically produced by the decay of X boson pairs that resulted in a very small surplus of matter, that PBH had nothing to do with this process and that the chance that PBH absorbed all of the antimatter was practically zero. Derek, if you now want to say that just more antimatter fell in than matter that is a different question. How much more do you mean?

 

[Phrak]

Yeah, but...

Could black holes serve as an imbalance catalytic.

 

[derek.basler]

Well, I'm not just going to throw out numbers. But I was wondering if perhaps just enough to produce an imbalance of matter and antimatter. Is there ANY speculation at all that black holes may prefer antimatter over matter? Has there ever been any papers posted on the subject that anyone may know of?

 

[derek.basler]

anything?

 

[spidey]

This isn't true. What is true is that the particle that falls into the black hole is always the particle with 'negative energy,' but nothing states that this particle must be the antiparticle. Antiparticles and particles are emitted via Hawking radiation with equal probability.

are particles with ' negative energy" and anti particles different?

 

[George Jones]

are particles with ' negative energy" and anti particles different?

You might want to read through the thread

https://www.physicsforums.com/showthread.php?p=619311#post619311.

 

[Arch2008]

Sorry, we lost power here in Ohio and when the power came back on after several days, some of us had no internet.
To clarify, scientists think that X bosons and anti-X bosons decayed in such a way that the quarks and leptons for 10^50 tons of matter had no antimatter counterpart and thus did not get annihilated. Derek, you are now saying that there would be less matter today, except that PBH’s somehow attract antimatter more than matter.
First off, we have no observational evidence of PBH’s. Second, you would have to show how our understanding of X boson pair decay is actually flawed and requires your “tweak” to match observations. Lastly, you would have to describe a mechanism other than random chance that caused this loss of antimatter. So, if we just accept that the scientists got the existence of PBH’s right (there may be only one within a half trillion km of the Earth) and X-boson pair decay wrong (its pretty iffy without proof of CP violation), then you just have to solve the problem of how what you think happened to the antimatter might have actually happened.
A matter particle and its antimatter particle counterpart have the same mass and spin, but differ in two respects, electric charge and magnetic moment.
http://www.lbl.gov/abc/Antimatter.html
Now black holes may have an electrical charge and these come in two types, Reissner-Nordtroem for non-spinning singularities and Kerr-Newman for spinning singularities.
http://en.wikipedia.org/wiki/Kerr_metric
So you could explore determining a way that the electrical charge of a PBH attracted antimatter but somehow repelled matter. That’s the best I can come up with.

 

[Phrak]

The labeling of matter and antimatter is arbitrary up to partlcle --family?

So under some arbitrary relabeling, I ask, what missing antimatter?

The question that is masked by all this talk about matter and antimatter (that have gone undefined) is__________.

 

[spidey]

You might want to read through the thread

https://www.physicsforums.com/showthread.php?p=619311#post619311.

Thanks for the info..

 

[derek.basler]

thank you very much arch. that was extremely helpful. Hopefully when I move on in my career (I am only a junior in high school), I can maybe prove or disprove any of these issues. I'll have to keep this idea in the back of my mind. Thanks again!

 

[Arch2008]

You're welcome, and good luck!

 

[theLHC]

hmm...
maybe there is some sort of boson particle such as the higgs boson that altered the properties of most of the existing antimatter and therefore caused the imbalance

just some thought coming out of a high schooler

 

[Chronos]

The universe has no net charge, for starters. Anti-matter is more hypothesis than fact. There should be tons of it, by some calculations, but there is not. The question is not where it 'went', more like why did we think there was so much of it?

 

[Arch2008]

“…why did we think there was so much of it?”

http://www.crystalinks.com/antimatter.html
http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980330a.html
http://www.answers.com/topic/antimatter

I think that there is ample reason to think this.

 

[LURCH]

So far as is known, there is no way for a particle of matter to form without an antimatter particle forming at the same time.

When you say "...Anti-matter is more hypothesis than fact..." exactly what do you mean?

 

[spidey]

I have recently been reading Moment of Creation by James Trefil, and I have stumbled upon the question, where has all the antimatter gone? I asked myself, what if micro black holes produced by the tremendous energy at the big bang are the answer? If you have an understanding in hawking radiation then you know particle-antiparticle pairs are produced at balck holes. What if, by chance, antiparticles were absorbed by these micro black holes more than regular particles. It could explain why there is more matter than antimatter. Has this been dissproved by anyone? Is this a plausible theory?

if there are equal number of matter and antimatter at the beginning then there should be equal chances of micro black holes formed with antimatter too...this is just opposite...so if you say antimatter gone because of micro black holes formed with matter,then matter should also have gone because of micro black holes formed with antimatter...

 

[TalonD]

this may be a dumb question, but how do we know there is no antimatter in the univers. By looking at some distant galaxy is there something about it that we can distinguish that it is made of matter rather than antimatter?

 

[derek.basler]

Well we receive many particles from distant galaxies, and none of them turn up to be antiparticles, so it gives us a good indication that they are not made of antimatter.

 

[Haelfix]

To the OP. In order to have a matter/antimatter asymmetry the necessary and sufficient conditions were layed out by Sakharov in the 60s.

A black hole in and of itself is not sufficient to meet these bounds, however a black hole and other physics is. So while this isn't exactly what you had in mind, its somewhat related.

For instance Grand unified theories provide a mechanism to have baryon number nonconservation and CP violation. So indeed, if you combine a black hole with something like that, you presumably satisfy the conditions necessary.

This is what's called black hole baryogenesis, and it has been looked at before (Hawkings and Zeldovitch were the pioneers afair). The idea being, a black hole while its radiating under the Hawking process can spit out a bunch of heavy particles, and they in turn can violate lepton or baryon number. The black hole in that case, acts like a sort of multiplier to the final observed asymmetry.

The problem is, you need a lot of primordial black holes in the early universe to be of relevance, and this in turn is very sensitive to inflation and is highly model dependant. Moreover Sphaleoron processes damp some of this as well.

You'd probably have to search arxiv for the modern parameter spaces where this hypothesis lives in. I don't know off the top of my head if its been falsified or whether its still active.

 

[TalonD]

where is all the antimatter. I was reading up on Fienman diagrams, in an electron / antielectron(positron) interaction, the two particles anihilate and yeild a high energy photon. but that is mathmatically equivilant to an electron absorbing a high energy photon and traveling backwards in time as a positron. So from that argument, an antiparticle is the same as a particle that is traveling back in time. So could the absence of antimatter be a consequence of the one directional nature of time? So to have equal quantities of matter and antimater, time would have to be bidirectional? Seems as reasonable as primordial black holes?

 

[derek.basler]

yea that actually sounds pretty interesting. But we can create anti-particles, so that would break times one-directionality right?

 

[Vanadium 50]

There are multiple parts to this question. The first question is "is there a global baryon asymmetry (the technical term for the matter-antimatter asymmetry) or are there pockets of matter and pockets of antimatter?" We don't really know the answer to this, but we do know that if there are pockets, they are quite large - perhaps 100 Mpc across. We know this because we don't see evidence of nearby annihilation radiation.

The second question is whether there were enough primordial black holes to force an asymmetry. I don't know for sure, but I suspect that the answer is "no". If the expected asymmetry was due to chance alone, it would mean you'd end up with an excess that is about the size of the square root of the number of PBH's. For example, a 10% matter-antimatter asymmetry would mean ~100 PBH's. A 1% asymmetry would mean ~10,000 PBH's.

The problem is that there's not enough dark matter out there. There is ~8x as much dark matter (including PBH's) as ordinary matter, which would suggest only 64 PBHs. We know that dark matter is very smoothly distributed, and we would need many trillions of them, not just 64. So this doesn't work out well quantitatively.

 

[butthead]

isnt it possible that the antimatter might have got liberated to form something outside the uiniverse and may be it is supporting the universe