B Are Antiparticles the Key to Understanding the Universe?

[Malek]

There is an assumption in cosmology say that there is another universe Composed of antiparticles?
I mean that the atom composed of positron rather than an electron, anti-proton rather than a proton and anti-neutron rather than a neutron.

 

[phinds]

There is an assumption in cosmology say that there is another universe Composed of antiparticles?
I mean that the atom composed of positron rather than an electron, anti-proton rather than a proton and anti-neutron rather than a neutron.

No, there are highly speculative theories regarding that kind of thing but no such assumption.

 

[mathman]

The problem that has not been solved is why matter exists? Big bang led to a lot of energy, where photons can split into matter and antimatter pairs. Why is there an excess of matter?

 

[Grinkle]

The problem that has not been solved is why matter exists? Big bang led to a lot of energy, where photons can split into matter and antimatter pairs. Why is there an excess of matter?

A boring (because I think its untestable) proposal might be that its anthropic.

The early universe was infinite in extent, there are many post-expansion regions where complete annihilation took place and some regions where either anti-matter or matter (by chance) pre-dominated. We can only exist in one of those areas, and we will name the region where we exist as "matter", not "anti-matter", because we can't completely shed the human pre-disposition to believe we are special.

Are there models that eliminate such conjecture by showing that large areas of either matter or anti-matter occurring by chance in an infinite universe are not possible?

 

[mathman]

A boring (because I think its untestable) proposal might be that its anthropic.

The early universe was infinite in extent, there are many post-expansion regions where complete annihilation took place and some regions where either anti-matter or matter (by chance) pre-dominated. We can only exist in one of those areas, and we will name the region where we exist as "matter", not "anti-matter", because we can't completely shed the human pre-disposition to believe we are special.

Are there models that eliminate such conjecture by showing that large areas of either matter or anti-matter occurring by chance in an infinite universe are not possible?

It seems highly unlikely, since these particles are created in pairs, so it is hard to see how they could separate on a large scale.

 

[Malek]

No, there are highly speculative theories regarding that kind of thing but no such assumption.

A boring (because I think its untestable) proposal might be that its anthropic.

The early universe was infinite in extent, there are many post-expansion regions where complete annihilation took place and some regions where either anti-matter or matter (by chance) pre-dominated. We can only exist in one of those areas, and we will name the region where we exist as "matter", not "anti-matter", because we can't completely shed the human pre-disposition to believe we are special.

Are there models that eliminate such conjecture by showing that large areas of either matter or anti-matter occurring by chance in an infinite universe are not possible?

believe me, I don't know

 

[PeterDonis]

Big bang led to a lot of energy, where photons can split into matter and antimatter pairs.

According to our best current model, the Big Bang happened at the end of inflation, and the reheating process that took place then put lots of energy into all of the Standard Model particles, not just photons. The current matter in the universe was not created by photons creating matter-antimatter pairs; it is what's left over after all of the particle-antiparticle pairs that could annihilate as the temperature went down, did annihilate. The reason we still have matter in our universe is that, when that annihilation took place, there was an excess of about one part in a billion of particles over antiparticles; so about one matter particle for every billion photons remained after the annihilation was complete.

The unresolved question is where that one part in a billion excess of matter particles came from: was it put there by the reheating process that took place at the end of inflation? (And if so, why?) Or did it develop because there are high energy processes, not currently included in our Standard Model of particle physics, that favor matter over antimatter instead of being symmetric between them? (And if so, what are those processes and how can we extend our models of particle physics to incorporate them?)

 

[PeterDonis]

It seems highly unlikely, since these particles are created in pairs

As stated in my previous post, your underlying assumption here, that the matter in our current universe was created as particle-antiparticle pairs from photons, is not correct.

We don't know enough about whatever process created the one part in a billion excess of matter in our universe to tell whether it is possible that there are other "universe" regions which had an excess of antimatter over matter instead.

 

[alantheastronomer]

The propositions put forth in posts #4 and #7 are not borne out by observations of the microwave background radiation.

 

[mark!]

As stated in my previous post, your underlying assumption here, that the matter in our current universe was created as particle-antiparticle pairs from photons, is not correct.

We don't know enough about whatever process created the one part in a billion excess of matter in our universe to tell whether it is possible that there are other "universe" regions which had an excess of antimatter over matter instead.

The Universe obviously has a baryon asymmetry, but what about the conservation of charge? Is there an equal amount of plus/minus charge in the Universe?

 

[PeterDonis]

The propositions put forth in posts #4 and #7 are not borne out by observations of the microwave background radiation.

Please give more details and references; I don't understand what you are referring to here.

 

[PeterDonis]

Is there an equal amount of plus/minus charge in the Universe?

As far as we can tell, yes, the universe (or at least the part that we can observe) is electrically neutral.

 

[DAH]

Hi
If the early universe created one more anti-matter in a billion over matter, then would stars, planets and life still evolve with opposite charges within atoms?

 

[phinds]

Hi
If the early universe created one more anti-matter in a billion over matter, then would stars, planets and life still evolve with opposite charges within atoms?

Exactly. We would just call it matter since as has already been pointed out, the distinction is arbitrary anyway.

 

[bahamagreen]

Exactly. We would just call it matter since as has already been pointed out, the distinction is arbitrary anyway.

Well, the distinction is arbitrary up to interacting with stars, planets and life of opposite charge; exchanging space probes, trading cards and letters, and handshakes leads to annihilation... :)

 

[phinds]

Well, the distinction is arbitrary up to interacting with stars, planets and life of opposite charge; exchanging space probes, trading cards and letters, and handshakes leads to annihilation... :)

No, we would call whatever world we lived in matter and the other stuff anti-matter, just like we do now. It's just words. The anti-matter would, as you say annihilate with our matter.

 

[alantheastronomer]

Please give more details and references; I don't understand what you are referring to here.

If there were areas where annihilations didn't take place they would show up as anisotropies in the microwave background radiation that just aren't there. Similarly, if there were a vast number of annihilations leaving a small excess of matter particles, the gamma radiation left from the annihilations would show up as a higher radiation excess than observed as the radiation of recombination.

 

[PeterDonis]

If there were areas where annihilations didn't take place they would show up as anisotropies in the microwave background radiation that just aren't there. Similarly, if there were a vast number of annihilations leaving a small excess of matter particles, the gamma radiation left from the annihilations would show up as a higher radiation excess than observed as the radiation of recombination.

Do you have references to support these claims? You appear to be saying that our best current model of the universe is wrong. You need to back up such a claim with strong evidence.

In particular, are you aware that the ratio of photons to baryons has been measured and is about a billion to one? (That is the basis for my statement in post #7 that the excess of matter over antimatter was about one part in a billion.)

 

[mark!]

If there were areas where annihilations didn't take place they would show up as anisotropies in the microwave background radiation that just aren't there. Similarly, if there were a vast number of annihilations leaving a small excess of matter particles, the gamma radiation left from the annihilations would show up as a higher radiation excess than observed as the radiation of recombination.

Do you have references to support these claims? You appear to be saying that our best current model of the universe is wrong. You need to back up such a claim with strong evidence.

In particular, are you aware that the ratio of photons to baryons has been measured and is about a billion to one? (That is the basis for my statement in post #7 that the excess of matter over antimatter was about one part in a billion.)

There are slight anisotropies in the CMBR. There has been much publicity about analysis of results from the Wilkinson Microwave Anisotropy Probe (WMAP) and Planck mission that show both expected and unexpected anisotropies in the CMB map. If we would look at the Universe far from our location, we would not see the same concentric cell structure, or a non-homogeneous Universe. There's still much debate regarding this subject, but the CMB map does indeed correlate with plane of the Earth orbiting the Sun. (There's about 250 million light years space between every shell in this picture). If you take a look at the distribution of quasars in the universe there seems to be a "quasar spherical void" roughly one billion lightyears in radius around us. How to interpret these observations? That is not up to me, but they are significant measurements not to be ignored.

 

[nikkkom]

If you take a look at the distribution of quasars in the universe there seems to be a "quasar spherical void" roughly one billion lightyears in radius around us. How to interpret these observations?

How about "accretion rates onto SMBHs in galaxy centers drastically decreased as galaxy mergers become much rarer"?

 

[mark!]

How about "accretion rates onto SMBHs in galaxy centers drastically decreased as galaxy mergers become much rarer"?

Do I understand you correctly that the distribution of quasars have already been irrefutably explained and supported by scientific evidence? That would be interesting, where can I read more about this? And what about the anisotropies of the CMB map?

 

[nikkkom]

Do I understand you correctly

No, you do not :)

 

[mark!]

No, you do not :)

Ah OK, so you were just hypothesizing then. I sounded a little bit like you've provided the answer to this proposed observation of which I wasn't aware, but these observations (quasar distribution + CMB anisotropies) will remain a mystery to science.

 

[phinds]

... these observations (quasar distribution + CMB anisotropies) will remain a mystery to science.

That seems overly pessimistic. Do you really think we will never figure it out?

 

[mark!]

That seems overly pessimistic. Do you really think we will never figure it out?

I meant that they will remain a mystery until now, I didn't mean that they will remain a mystery in the future. But I'm sceptical whether these findings indicate that the Universe has a center (which these spherical CMB anisotropies, and spherical distribution of quasars are implying), but I don't have any other, more plausible, explanation. Hopefully we will find it soon!

 

[phinds]

... I'm sceptical whether these findings indicate that the Universe has a center (which these spherical CMB anisotropies, and spherical distribution of quasars are implying),

They do not imply any such thing. There is no center. I think you are confusing the Observable Universe, which DOES have a center of course, with The Universe, which does not.

 

[Bandersnatch]

How to interpret these observations? That is not up to me, but they are significant measurements not to be ignored.

I think you're overselling their significance.
In particular

(There's about 250 million light years space between every shell in this picture).

The quantized redshift is like the large-scale structures and voids that sometimes pop up in the literature - for every paper that says they exist, there's another showing them to be artefacts of the statistical methods employed in analysing the data. That does not constitute convincing evidence that periodicity exists, and for anyone not involved in researching this topic is best to ignore it. Same as one ignores any other claim presented with insufficient evidence.

If you take a look at the distribution of quasars in the universe there seems to be a "quasar spherical void" roughly one billion lightyears in radius around us.

That's not what the picture shows (paper, couldn't find the exact source of the figure, but this is the same author and discussion). It suggests a quasar-less sheet-like void, 3 Gpc away (bisecting the picture vertically), not an Earth-centred spherical one.
In any case, look at the date of that paper. I strongly suspect the anisotropy disappeared with further observations (if you can find modern papers on this topic, please post links).

The closest quasar detected so far is well within 1 Glyrs:
https://en.wikipedia.org/wiki/Markarian_231

As for the 'axis of evil' - the mere fact that it is aligned with the ecliptic strongly indicates that it is a local effect, and not an indication of some zany heliocentric cosmology.

All of these are interesting in the 'Where is Waldo' sense - only instead of for the eponymous character, this is searching for boobery in the data.

 

[Chronos]

Yes, there are quasars less distant than 1 billion light years as Bandersnatch noted, see also https://www.nasa.gov/feature/goddar...rest-quasar-is-powered-by-a-double-black-hole if wiki is not your cup of tea. The other stuff he mentioned is also more factually consistent than the mythology to which he refers. What we think we know is not necessarily the final word on the reality of deep space and it is certainly possible to produce any number of statistics from data already archived that seem to defy logic. Some people have actually made careers out of parading the dog faced boys of cosmology before the gullible. Objective and responsible researchers just roll their eyes at such nonsense. They find the subject uncomfortable; not because of any whitewash conspiracy, but, because it's not easy to engage in s*** slinging without some of it sticking to you.

 

[alantheastronomer]

Do you have references to support these claims? You appear to be saying that our best current model of the universe is wrong. You need to back up such a claim with strong evidence.
I'm not making any claims, I'm merely posing questions that need to be addressed if we are to have a full understanding of the origin of the universe.

In particular, are you aware that the ratio of photons to baryons has been measured and is about a billion to one? (That is the basis for my statement in post #7 that the excess of matter over antimatter was about one part in a billion.)

Yes, I'm aware, and I have no objection to your statement. I was merely pointing out that there should be an artifact of the gamma rays produced during the era of annihilation and there isn't. If you're suggesting that the photon to baryon ratio is a product of the era of annihilation as opposed to the era of recombination, then we should also see a separate remnant from the era of recombination. (By the way, if the microwave background radiation is due to recombination then it shouldn't be considered as thermal blackbody radiation, but rather as a redshifted lyman alpha emission line!)

 

[PeterDonis]

I was merely pointing out that there should be an artifact of the gamma rays produced during the era of annihilation

No, there shouldn't. The photons produced during annihilation have redshifted during the intervening time; their present temperature is the temperature of the CMB, because those photons are the CMB. See below.

we should also see a separate remnant from the era of recombination

No, we shouldn't. Recombination did not produce photons; it just drastically increased the mean free path of photons that already existed.

More precisely, before recombination, photons were constantly being created as electrons and nuclei combined into atoms, and then destroyed as they hit atoms just formed and split them apart again. The net effect was a constant photon number. Recombination simply established that constant photon number as free-traveling photons in a transparent universe, rather than an average of constant creation and destruction in an opaque universe.

 

[mark!]

It suggests a quasar-less sheet-like void, 3 Gpc away (bisecting the picture vertically), not an Earth-centred spherical one

Quasars are the most distant objects discovered by astronomers in the Universe. The peak epoch of quasar activity in the Universe corresponds to redshifts around 2, or approximately 10 billion years ago. An extreme redshift could imply great distance and velocity, but could also be due to extreme mass, or perhaps some other unknown laws of nature. The most distant quasar yet spotted sends its light from the Universe’s toddler years. existed when the universe was only 690 million years old, right when the first stars and galaxies were forming.

My point: if you observe quasars (that represent the Universe's toddler years) in the centers of the most distant galaxies in all directions, then how does this not make us the center?

 

[Bandersnatch]

My point: if you observe quasars (that represent the Universe's toddler years) in the centers of the most distant galaxies in all directions, then how does this not make us the center?

You observe them also in centres of relatively nearby galaxies in all directions. But I think you're asking why do they peak in activity at roughly the same distance?
Because, as you say, these are the objects associated with the early history of the universe. It is then a simple consequence of the finite speed of light that you see things that happened during the 'toddler years' far away and at roughly the same distance all around you.
This is much the same as how all observers see the CMBR as centred around each of them. It makes you the centre of your observable universe only. Any other observer elsewhere in the universe is expected to see a similar distribution of quasars.
I believe it has been alluded to by others in this thread already.Also, can you be clearer about attribution of the bits you're quoting from other articles (and how they're relevant)? In the paragraph above I can see sentences copied from the Wikipedia article, and from Science News (unattributed).
At least put them in quotation marks. Otherwise it's hard to tell where you're making your own points, and where you're providing sources in support of those points.
Thanks.

 

[mark!]

You observe them also in centres of relatively nearby galaxies in all directions

This is true for galaxies nearby, but a galaxy far away from us, say in between us and our observable Universe, isn't seeing the same distribution of quasars in all directions, right? Or is the distribution of quasars, just like the CMB anisotropy, distributed the same way for every galaxy?

 

[Bandersnatch]

but a galaxy far away from us, say in between us and our observable Universe, isn't seeing the same distribution of quasars in all directions, right?

It should be the same, yes. For the reasons given above. I.e., every (comoving) observer sees the universe at the same age, so every age-dependent distribution should be the same.

 

[phinds]

Or is the distribution of quasars, just like the CMB anisotropy, distributed the same way for every galaxy?

Yes, it's the same no matter where you are in the universe. Again, there is no center.

 

[mark!]

Yes, it's the same no matter where you are in the universe. Again, there is no center.

I'm not yet able to wrap my mind around the notion that quasars are the most distant objects (the Universe’s toddler years) in all directions, as seen from the Milky Way, but at the same time this is true for a galaxy that is located somewhere in a random direction near the edge of the observable Universe, in between the Milky Way and those distant quasars. How can they possibly observe the same thing as us? There must be something I'm missing here.

 

[PeterDonis]

How can they possibly observe the same thing as us?

They aren't observing the same quasars that we observe. They are observing our part of the universe as it was billions of years ago. At that time our part of the universe would have looked similar to the part of the universe that we currently observe to have quasars in it.

 

[Grinkle]

How can they possibly observe the same thing as us?

Imagine you are in the middle of the ocean and in a region with no land for many hundreds of miles in any direction, and your view is curtailed by the horizon. You see the ocean as far as you can see in every direction.

Now imagine another observer just over the horizon. Knowing what you know for certain about the ocean, you know for sure that the person just over the horizon sees some of what you see, some of what you cannot see, and that what you cannot see but they can see looks just like what you can see at a large enough scale, probably at a scale of 10x or 100x whatever the average length of the waves are. Don't imagine any approaching storms. ;-)

What you know for certain about the ocean in terms of the "observable ocean" being the same as what is over the horizon is how it is being suggested to you to think of the entire universe vs the observable universe.

 

[phinds]

I'm not yet able to wrap my mind around the notion that quasars are the most distant objects (the Universe’s toddler years) in all directions, as seen from the Milky Way, but at the same time this is true for a galaxy that is located somewhere in a random direction near the edge of the observable Universe, in between the Milky Way and those distant quasars. How can they possibly observe the same thing as us? There must be something I'm missing here.

To state what Peter and grinkle have already said but in slightly different terms, what you are missing is the Cosmological Principle, which states that the universe on large scales is homogeneous and isotropic (plus of course the fact that it at the very least WAY bigger than the Observable Universe)

https://en.wikipedia.org/wiki/Cosmological_principle

This leads to the obvious conclusion that there is no center and things on a large scale look identical no matter where in the universe you are.

Check out the link in my signature.

 

[alantheastronomer]

I'm not yet able to wrap my mind around the notion that quasars are the most distant objects (the Universe’s toddler years) in all directions, as seen from the Milky Way, but at the same time this is true for a galaxy that is located somewhere in a random direction near the edge of the observable Universe, in between the Milky Way and those distant quasars. How can they possibly observe the same thing as us? There must be something I'm missing here.

Quasars don't appear to be permanent; they seem to evolve over time, becoming quiescent galactic nuclei of normal galaxies. This is why there seems to be a dearth of them in the nearby region of the universe. We see quasars as they were tens of billions of years ago; shifting to the point of view of a galaxy located near the edge of the observable universe, you're no longer seeing them as they were tens of billions of years ago, instead you're seeing them as they look in the "present" day - as quiescent galaxies. You now also have a new horizon where you can look tens of billions of light years distant and observe new young quasars as they were tens of billions of years ago!

 

[mark!]

They aren't observing the same quasars that we observe. They are observing our part of the universe as it was billions of years ago. At that time our part of the universe would have looked similar to the part of the universe that we currently observe to have quasars in it.

Does this mean that other galaxies also see these distant quasars in all directions in the same way we do? (Because if they don't, that would imply that we're the center of the Universe, and not them).

Look at this picture I've quickly drawn: if our galaxy is A, and some random galaxy is B (see left image), is B really seeing the Universe's toddler years (quasar distribution) the same way A (us) are doing right now (see right image)?

 

[PeterDonis]

Does this mean that other galaxies also see these distant quasars in all directions in the same way we do?

Yes, but they are seeing those quasars billions of years away from them, and therefore they are seeing things as they were billions of years ago.

In other words, it isn't that our universe has normal galaxies here now, and quasars billions of light-years away now. Our universe has normal galaxies now, and quasars billions of years ago.

 

[CWatters]

It seems highly unlikely, since these particles are created in pairs, so it is hard to see how they could separate on a large scale.

Was it a large scale when they were created?

 

[mark!]

Yes, but they are seeing those quasars billions of years away from them, and therefore they are seeing things as they were billions of years ago.

In other words, it isn't that our universe has normal galaxies here now, and quasars billions of light-years away now. Our universe has normal galaxies now, and quasars billions of years ago.

So, there are no quasars right now? Indeed, there were quasars billions of years ago, but none of them exist right now?

This leads to the obvious conclusion that there is no center and things on a large scale look identical no matter where in the universe you are.

Does this mean that the Milky Way looks like a quasar from the viewpoint of a quasar?

I still don't fully grasp the notion that all these distant quasars (which surround us in all directions, the so called 'toddler years' of the Universe) seem to move away from us with the highest possible speed that a galaxy could move away from any other galaxy. Quasars in the north direction of our Solar System have redshifts that are equal to quasars with equal distance to us in the south direction of our Solar System. How then is it possible that a random galaxy (somewhere between the Milky Way and these quasars, in a random direction) is able to observe the same cloud of distant quasars surrounding that galaxy, with the same quasar-redshifts that we're seeing? It doesn't make sense to me how that random other galaxy could have the same viewpoint towards these quasars as us (probably because I don't understand it correctly).

 

[Justin Hunt]

@Mark you are thinking about this the wrong way. You never see anything in its present state, everything you see is in the past. The fraction of a second it takes for the photons to travel from your computer screen to your eyes and then to be processed means you are seeing your screen how it was a fraction of a second ago. While this isn't significant when we are looking at objects here on Earth, it is very important when observing the universe. When you observe an object millions of light years away, you are seeing what it looked like millions of years ago, not how it is right now at this moment. Big Bang theory has the universe expanding into its current state with everything starting at the same time. the reason we see these Quasars at far distance in all directions is because that many billions of years ago they were very common. When we look at closer objects, they are much less common and we won't see anything. No matter where you are in the the universe, closer objects will be seen closer in time to the present and further away objects will be further back in time. If we are in Galaxy A and you see a Quasar in Galaxy C, someone in Galaxy B, close to galaxy C probably won't see said Quasar because they are seeing Galaxy C much closer to the present then we are.

 

[PeterDonis]

So, there are no quasars right now?

Do you see any in our near neighborhood?

Since as far as we can tell the universe is homogeneous, then anywhere in the universe "right now" looks similar to the part of the universe where we are, right now.

You do realize that when we see quasars billions of light-years away, we are seeing them as they were billions of years ago? So those observations are not telling us what those distant parts of the universe are like "right now"; they are telling us what those distant parts of the universe were like billions of years ago.

Does this mean that the Milky Way looks like a quasar from the viewpoint of a quasar?

No, it means that billions of years ago, in our region of the universe, there wasn't the Milky Way; there was a quasar. In other words, our region of the universe has evolved; it is not the same now as it was billions of years ago.

 

[timmdeeg]

I still don't fully grasp the notion that all these distant quasars (which surround us in all directions, the so called 'toddler years' of the Universe) seem to move away from us with the highest possible speed that a galaxy could move away from any other galaxy.

I strongly recommend to read Phinds's article (see his signature) to clarify this key question. At all times things are moving away from each other in all directions, regardless where you are in the universe. Someone very far away from your position will see other galaxies and other quasars but the phenomenon that from any arbitrary position things are receding holds.

 

[Justin Hunt]

@PeterDonis isn't the question of why our observable universe is made of matter still an open question? my understanding is that some kind of asymmetry is just our best guess at the moment. I believe we discovered asymmetry in the weak force, but it wasn't enough to account for our observable universe being all positive matter. I would imagine this is the main avenue of research mainly because it is something that can actually be tested.

If we knew the matter to antimatter composition of our universe and how large our observable universe is compared to our universe, then we would be able to determine statistically how likely it is for the entire observable universe to be comprised of only one or the other. If the entire universe is dominated by matter, then this would obviously be 100%. But, depending on the composition of the universe, it could be nearly 100% chance as well even with no asymmetry. Unfortunately, it is unlikely we will ever know the composition of the entire universe, which is why focusing on matter/antimatter asymmetries makes much more sense.

I have an idea for how matter and antimatter could have separated. Big Bang theory has the entire universe expanding by many orders of magnitude. Now, if matter and antimatter pairs were being created at tremendous rates, then couldn't pieces of pairs annihilate with other pieces of pairs and allow some random distribution of the matter to antimatter ratios (Brownian motion)? This would cause slight fluctuations in the matter to antimatter distribution that would be magnified as the universe expanded. would it be possible for slight variations such as this to be magnified to the size of the observable universe?

 

[PeterDonis]

isn't the question of why our observable universe is made of matter still an open question?

Yes. I believe I already said that early in this thread.

If we knew the matter to antimatter composition of our universe and how large our observable universe is compared to our universe, then we would be able to determine statistically how likely it is for the entire observable universe to be comprised of only one or the other.

According to our best current model, our entire universe is spatially infinite. Our observable universe is spatially finite, meaning there is no way to compare its volume with the volume of the entire universe. So this method doesn't help.

I have an idea for how matter and antimatter could have separated.

Please review the PF rules on personal speculations.

 

[Justin Hunt]

@PeterDonis Sorry for breaking the rules! I will remove the speculative part and ask it as a question. My understanding of Big bang theory is that the concentration of matter in the universe was due to quantum fluctuation in the early stages (I am talking about the location of galaxies and other structures, most of space is empty). My question is then would any fluctuation in the distribution of matter and antimatter in the early stages of the big bang lead to large areas dominated by matter and antimatter at this point?