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ETpro's avatar

Why did the Big Bang make more matter than antimatter?

Asked by ETpro (34466points) August 17th, 2010

The Big Bang, to the best of our present knowledge, produced a great deal of matter and antimatter. There was enough antimatter around that some still survives today, 13.75 billion years after the BB.

Generally, when you have a reciprocal relationship in nature, things get produced in equal amounts. Of course, in the case of the Universe, if that had been true the entire creation would soon have annihilated itself. Thankfully, that did not happen. There was more matter than antimatter, and so matter won and we are here today.

Why wasn’t the equality of polar opposites upheld in the Big Bang?

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29 Answers

wundayatta's avatar

It doesn’t really matter, does it?

ragingloli's avatar

He misplaced some of the matter because his place looks like after an explosion.

CMaz's avatar

I believe it is equal.
Antimatter being anti and spread out AHEAD of matter itself. We have just not caught up to it and it having a great spread pattern. Think of a shotgun blast pattern, the target being infinity.

That pattern gets pretty broad.

Ah, what the hell do I know. But is a better answer then those. ;-)

BhacSsylan's avatar

I’m really not sure about the original question, not being a physicist I have no clue how the equations work out on that (besides “hey, we’re here. Totally means there was more matter”). I do have to make one correction, though. That link you have doesn’t actually pertain to remnants of antimatter left from the big bang. The intriguing thing about that supernova, and those general type of supernovae, is that the star was so hot that it actually created antimatter. It took photons and split them (er, sorta) into electron-positron pairs. So, there wasn’t necessarily any extra antimatter to start, it only needed what it created to start and maintain it’s nova. Which is pretty cool in it’s own right, frankly.

Still, though, good question. Wonder if there’s any physicists on fluter who could enlighten us.

BhacSsylan's avatar

@hiphiphopflipflapflop Wow. That’s completely fascinating. Could answer the question quite well, although I think they still have to answer the question of why the hell that happens. But still, wow. Good old Fermilab. Bending our supposed rules of spacetime on a regular basis.

As I was writing that, i accidental wrote ‘God old Fermilab’, which was an entertaining enough slip I though i would share

Fyrius's avatar

Obviously, not all things that are opposite are necessarily also equal, in number or size or intensity. Emptiness is also far more common than matter in the known universe, and cold is more common than heat, and darkness more common than light. And from where we’re standing, “down” only goes on for about six thousand kilometres before you’d reach the core of the earth and the same direction becomes “up” again, whereas “up” goes on quite a bit further.

I also think you’re seeing patterns that aren’t objectively there. For starters, are the opposites you’re generalising this principle of equality from, the same kinds of opposites as the matter/antimatter opposition?
Notice that we’d call the matter/antimatter distinction as well as the things I just mentioned “opposites”, yet none of the things I mentioned are opposites in the same way that matter and antimatter are opposites; that’s a matter of positive and negative charge, not of presence versus absence or literal directional opposition.

So, to cut down to the real point: do we have any physical reason to expect that positively and negatively charged particles should exist in equal amounts, or is this a generalisation from examples that are actually fundamentally different?

I don’t know the answer. I don’t know what data you based your generalisation on.

Winters's avatar

From what I understand from several physics professors, Antimatter for some odd reason is more unstable than Matter, hence by this point in time, most if not all antimatter has deteriorated. But hey, that’s still a question that physicists are arguing about. Until we can figure out what happened at time 0, then I don’t think we’ll ever know.

ETpro's avatar

@hiphiphopflipflapflop Awesome answer and link. Thanks.

@BhacSsylan Thanks for offering some expert analysis. I hope more physicists can join in the discussion.

@Fyrius I do not know how the singularity that created matter and antimatter operated, but as the Fermilab article notes, the observed results in their experiment, while far less symmetrical than the Big Band matter/antimatter asymmetry, still violates CP symmetry. That’s why I asked.

This wasn’t one of those questions where I asked to see if others knew what I already know. :-)

Fyrius's avatar

I’d never heard of CP symmetry until now; that’s probably the answer to my question why you would expect there should be an equal quantity of both types of matter. All right. :)

But it also says here that other CP symmetry violations have been known since the sixties.

ETpro's avatar

@Fyrius Please pardon my typo. I meant to write that Fermilab’s experimental results were far MORE symmetrical than the result of the Big Bang.

I wonder if CP symmetry violation answers another of my questions; that being, “Why does the arrow of time go only in one directive?. CPT symmetry states that if an operation violates CP symmetry, then T (time symmetry) must collapse, sending time in the forward direction only. Thus if something in the physics of the Big Bang violated CP symmetry, wouldn’t that fix the arrow of time for all time, making time irreversible within the Universe so created?

I’m not a physicist, so I am way over my depth in this conjecture. Somebody with more knowledge of the topic please jump in and correct me if I am talking nonsense.

Dr_Lawrence's avatar

It is because Penny possesses much more powerful attractive forces than do Sheldon, Leonard, Howard and Rajesh combined.

The latter four are comprised almost entirely of matter while the first mentioned is clearly made entirely of anti-matter.

This phenomenon seems to contradict the fundamental relationship between mass and gravitational attraction!

Hobosnake's avatar

Actually I read an article on this recently. It didn’t say that the big bang necessarily made more antimatter than matter, but more that in antimatter/matter reactions, matter is either slightly more likely to be produced or slightly more matter is produced. I remember the margin of difference being either 17% or 1.7% or .17% or something like that; all I remember is that it was a lot smaller than one might think considering matter’s current prevalence over antimatter. However, given enough time (as much time as evolutionists give the universe, at least), such a difference would make the prevalence we see now.

To be honest, I’m a creationist, so I’d say a ton more matter was created in the first place and that that tendency towards more matter than antimatter was also a designed tendency, but either way I believe that’s the current evolutionary standpoint on the problem.

One article (I don’t think it’s the one I read) on the breakthrough can be found here.

BhacSsylan's avatar

@ETpro How do you know that the fermilab result is more symmetrical then the big bang? I may have missed some information, so pardon me if i did, but if you take, say, that the big band created 100 times more matter then is currently present, then that 1% would be all that’s required. As time went forward, matter and antimatter annihilated as they’re apt to do, and eventually we’re left with the matter we now have and very little antimatter left.

Of course, that hinges on the Big Bang creating 100 times the matter currently around, which is a hypothesis I have no evidence for, but i don’t see why this wouldn’t be possible. Also consider that there are other violations of CP symmetry which allow for even more matter to be around, Fermilab’s is only the biggest violation found thus far, as far as I could tell.

FireMadeFlesh's avatar

There are unequal amounts of antimatter an matter due to quantum fluctuations. In a perfectly uniform universe, there would be equal amounts of matter an antimatter produced, but the statistical randomness involved in quantum mechanics means that the probability of matter or antimatter condensing out of the pure energy of the big bang is skewed one way or another at a particular point in time. It just so happens that matter was favoured, so what we have left is the difference between the matter and antimatter that was formed.

ETpro's avatar

@BhacSsylan Like @Hobosnake I recall having read that the likely disparity between Matter and Anitmatter in the nascent Universe was much larger. However, looking it up just now, I found this. If this explanation is right, then the numbers match pretty well what Fermilab found.

@FireMadeFlesh It makes you wonder if antimatter had won, would it matter. Would we still be here, just with every sub-atomic particle in us charged opposite of what we are in this incarnation?

hiphiphopflipflapflop's avatar

@ChazMaz, nothing gets “ahead” or “behind” because space itself “bangs” along with matter (and anti-matter). In other words, don’t imagine the Big Bang in terms of an explosion taking place in a pre-existing space. It’s much more like blowing up a balloon from a mathematical point where the balloon’s surface is a compactification of our three-dimensional space down to two dimensions (i.e. Big Bang for Flatlanders).

That balloon is still appears to be expanding, and that expansion appears to be accelerating.

(See: Metric expansion of Space.)

@FireMadeFlesh, my understanding is that the initial fluctuation starts off much too hot for there to even be a distinction between matter and anti-matter, and that the distinction comes about via spontaneous symmetry breaking as the universe cools down through the Grand Unification temperature of ~10^27 K. The assumption being that we start off around the Planck temperature of 1.416785(71) × 10^32 K.

hiphiphopflipflapflop's avatar

@ETpro, your link appears to square with what I’ve read before (specifically, this book).

FireMadeFlesh's avatar

@hiphiphopflipflapflop Its been years since I studied this, so you may be right. Quantum fluctuations are certainly responsible for the lumpiness of the universe, but maybe not for matter/antimatter asymmetry. In any case, the asymmetry has to have arisen from the string level rather than the quantum level, since quantum assumes pre-existing positive and negative quarks and leptons. Statistical fluctuation would, in my opinion, produce the asymmetry though, so maybe it occurred on a more fundamental level than the Standard Model.

hiphiphopflipflapflop's avatar

I’ve broken Guth’s book out again and discovered something I didn’t really pick up on back when I first read it. With the Standard Model, there is nothing compelling the charged leptons (electrons, muons and taus) to have exactly equal and opposite charge of protons (in other words, exactly -3/2 the charge of up, charm and top quarks and exactly thrice that of down, strange and bottom quarks). A Grand Unified Theory (GUT) should establish some sort of inherent relationship between leptons and quarks that dictates this rather than leaving them as two separate input parameters.

Simple GUTs result in proton decay, but this has not been reported yet, despite quite heroic attempts at looking for it.

Part of me was doubtful that CERN would come up with anything on Higgs. But recently, I noticed ‘t Hooft wrote a little note on his home page that stomped on some simple dumb skepticism of mine. What I hadn’t considered is that his whole success at renormalizing the electroweak theory as a graduate student hinges on the Higgs mechanism and spontaneous symmetry breaking, which is why he did it and not his supervisor (Veltmann), who had the same tools but beat his head against the wall for years on the problem (and who to this day, I believe is still a Higgs doubter).

Anyway, I’m suddenly more bullish on there being some breakthroughs in the near future that will get us from the Standard Model to a Grand Unified Theory.

FireMadeFlesh's avatar

@hiphiphopflipflapflop I once read that protons have a half-life of around one billion years, but I never bought it because they didn’t say what protons decay into.

hiphiphopflipflapflop's avatar

Way off! Lower limit of proton half-life experimentally is up to 6.6×10^33 years (2009, Super-Kamiokande). Quite possibly absolutely stable. I can’t believe anyone with any knowledge of experimental physics, cosmology or astrophysics would seriously advance such a low figure.

FireMadeFlesh's avatar

Wow, okay. I would imagine that they are absolutely stable, since there is no simpler particle for them to decay into without violating confinement theory.

ETpro's avatar

@hiphiphopflipflapflop Fascinating back and forth with @FireMadeFlesh. Thanks to you both. Given that I find this topic fascinating but the math to explore it deeply beyond me, is Guth’s book one I should add to my reading list?

Oh, and I certainly hope your optimism for CERN;s efforts turns out to be on target.

hiphiphopflipflapflop's avatar

Guth’s book isn’t light reading, but he doesn’t rely on equations to tell the story. I’d recommend it to the lay reader with a strong interest in the subject.

hiphiphopflipflapflop's avatar

@FireMadeFlesh here is one of the clearer Feynman diagrams online I’ve found showing a hypothetical proton decay: a virtual ‘X’ boson is exchanged between a down quark and one of the up quarks in a proton. The down quark becomes a positron and flies off. The up quark is changed into an anti-up quark. The new anti-up quark and the remaining up quark consitute a neutral pion (which will mostly likely soon decay into two gamma rays).

This ‘X’ boson (and a ‘Y’ boson partner) does things not allowed by the Standard Model, but they come about when the separate gauge groups of the Standard Model – SU(3) x SU(2) X U(1) – are packed into a single gauge group – SU(5) – to make the first published Grand Unified Theory (I only “sort of” understand what that means!).

FireMadeFlesh's avatar

@hiphiphopflipflapflop Fascinating, thanks! I might get a hold of that book sometime too – I only have a rudimentary knowledge of the maths, so it should be interesting.

Luiveton's avatar

The universe would have disappeared in a big puff of self-annihilation almost as soon as it began if the number of matter and antimatter was equivalent. One part of an article that seemed to catch my attention was—> “Experiments in accelerators now tell us that for every 10 billion antiprotons present in the early universe, there were 10-billion-and-one protons. The same tiny imbalance applied to other particles, such as electrons, too. At some point in cosmic history, matter and antimatter met and annihilated. Left behind, those extra particles eventually came together and formed the matter-filled universe we know today.”
“Other ideas to explain the imbalance of matter and antimatter in the infant universe include a hypothetical particle called the majoron, which is thought to have created neutrinos and antineutrinos, but not in equal amounts. That could eventually have led to an imbalance between matter and antimatter.”

ETpro's avatar

@Luiveton Aha. THanks.

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