Antimatter, (Where has it gone?)

[Daniel.132]

hey everyone

A great question that has been bugging my mind for a long time is "Where has all the antimatter gone in our universe?" The Big bang produced matter and anti matter in equal amounts. Yet there is still very little antimatter in our unviverse, or at least part of it. Where has all the antimatter gone, and why.

Please tell me your views on this post.

Daniel.132

[belovelife]

Well if you ask me, matter/anti-matter pairs mAke up the nucleus of the atom

where the constant annihilation and re-creation define the weak force of gravity

the frequency of this defines a few things

electromagnetic spectrum released from the atom

Which changes as the frequency increases ( see electromagnetic spectrum

of hydrogen vs dueterium)

if we had data calculated would define molecular interactions and define

physical propertes of different combos in a simulation

[CraigD]

Hi Daniel – welcome to hypography! :shrug:

hey everyone

A great question that has been bugging my mind for a long time is "Where has all the antimatter gone in our universe?" The Big bang produced matter and anti matter in equal amounts.

Starting with the assumption that the BB produced exactly equal amount of matter and antimatter (which is not what physicists now believe – more on that later), and noting that matter and antimatter annihilate, creating electromagnetic energy (photons), rather than asking “where has the antimatter gone?”, you might better ask “why is there any matter still around?” Why didn’t the exactly equal parts of matter and antimatter annihilate shortly after they formed after the big bang, resulting in a universe filled with nothing but photons?

 

This is the question physicists puzzled over for some time after Dirac predicted its existence in the late 1920s, and Anderson and others confirmed existed and studied in the 1930s, eventually figuring out that quantum theory predicted slightly more matter than antimatter being generated by the BB – a now famous asymmetry, or “symmetry breaking” of the theory.

 

So the answer to “where has all the antimatter gone?” is “it all (or very nearly all) annihilated with matter, producing the photons we now observe as the cosmic microwave background.

 

Textbooks and the internet have lots of good material on this. A good starting place is the wikipedia article “baryogenesis”.

[Jay-qu]

Hi Daniel – welcome to hypography! :lightning

 

Starting with the assumption that the BB produced exactly equal amount of matter and antimatter (which is not what physicists now believe – more on that later), and noting that matter and antimatter annihilate, creating electromagnetic energy (photons), rather than asking “where has the antimatter gone?”, you might better ask “why is there any matter still around?” Why didn’t the exactly equal parts of matter and antimatter annihilate shortly after they formed after the big bang, resulting in a universe filled with nothing but photons?

 

This is the question physicists puzzled over for some time after Dirac predicted its existence in the late 1920s, and Anderson and others confirmed existed and studied in the 1930s, eventually figuring out that quantum theory predicted slightly more matter than antimatter being generated by the BB – a now famous asymmetry, or “symmetry breaking” of the theory.

 

So the answer to “where has all the antimatter gone?” is “it all (or very nearly all) annihilated with matter, producing the photons we now observe as the cosmic microwave background.

 

Textbooks and the internet have lots of good material on this. A good starting place is the wikipedia article “baryogenesis”.

The question now becomes, what is the origin of this asymmetry?

 

Also, worth noting the cosmic background is a thermal relic (one of the best black body curves in the universe). And so without some severe rethermalisation all of this relic could not have been produced by annihilations as they provide sharp energy peaks.

[Buffy]

The question now becomes, what is the origin of this asymmetry?

The thing I've always found fascinating is the fetish physicists seem to have for symmetry. Seriously, the favored--and barely supported--theory of the moment is "super-symmetry?" Why?

 

Well, I've had enough math to know why. Symmetry is beautiful (see Turtle's numerous threads mapping numbers onto wonderfully symmetric patterns). But the artist side of me--in spite of spending so much time programming these days, I'm really a *marketing* person--revels in asymmetry. Why are 90% of people right-handed? Why not 90% left-handed? Ditto the asymmetry of handedness in organic chemistry?

 

Why does it *have* to be symmetric?

 

I'd say that the glass-half-full complement to Jay's question really is, Why is it not *more* asymmetric?

 

Mr. Monk, those are people. Maybe they weren't the same size, :lightning

Buffy

[Jay-qu]

The thing I've always found fascinating is the fetish physicists seem to have for symmetry. Seriously, the favored--and barely supported--theory of the moment is "super-symmetry?" Why?

 

Well, I've had enough math to know why. Symmetry is beautiful (see Turtle's numerous threads mapping numbers onto wonderfully symmetric patterns). But the artist side of me--in spite of spending so much time programming these days, I'm really a *marketing* person--revels in asymmetry. Why are 90% of people right-handed? Why not 90% left-handed? Ditto the asymmetry of handedness in organic chemistry?

 

Why does it *have* to be symmetric?

 

I'd say that the glass-half-full complement to Jay's question really is, Why is it not *more* asymmetric?

 

Mr. Monk, those are people. Maybe they weren't the same size, :lightning

Buffy

I know this could go on for a while in another thread but there are more motivations to supersymmetry than just nice symmetries.. take the gauge coupling unification - or the fact that it can easily supply a weak scale wimp.

[coldcreation]

A great question that has been bugging my mind for a long time is "Where has all the antimatter gone in our universe?" [...] Where has all the antimatter gone, and why[?]

 

 

Surely the so-called antimatter problem (why the universe contains a quantifiable asymmetry between matter and antimatter) is one of the most outstanding dilemma's in all of science.

 

The resolution of why there exists something rather than nothing, and why matter came to dominate over antimatter, will impact profoundly our understanding of the physical laws (which for the most part are symmetric in nature, time reversible).

 

Even stranger is the conclusion that: if for each type of matter particle there is a matching antimatter particle, then it would imply that some particles originally had no matching antimatter particles. During the formation process, in the first micro-fraction of a second after the initial deflagration or big bang (whatever it was nobody knows), antimatter and matter annihilate to form gamma rays. The asymmetry of matter and antimatter cause an excess of matter, which remains the same forever. The antimatter would have been totally annihilated.

 

Think of a movies, with a story, a plot, the setting and scenery are simplified, perfectly adapted to the condensation of a stage-set. Eventually, if time is reversed, an unbelievable set of coincidences brings together all that exists, including space itself. The matter-antimatter asymmetry and cockeyed decoupling are entirely managed by theatrical conventions, just as stage characters are controlled by theatrical conventions.

 

The most important scene was left out of the plot (the big bang itself). It was not that the scene was edited from the story to keep it under 90 minutes. The scene had never been shot. In fact it has never been written; at least not convincingly, using physics. It’s the scene that would depict the conversion of nothing into something, the transformation of a peaceful void into a raging fury, from t = nothing (t = 0), to t = 1, 2, 3 and so on. The scene would have broken all the rules of conventional cinematography. It would have demonstrated why there was a gargantuan explosion (again, call it what you will), how the cosmic radiation was brought forth and why there exist something rather than nothing.

 

 

Cool.

 

 

There are many books that explains the issue quite well. Here is one of them (read the first Chapter for free ):

 

The Mystery of the Missing Antimatter (by Helen R. Quinn & Yossi Nir), 2008

 

This book also touches upon stuff that is neither matter, nor antimatter, another one of the deepest mysteries of modern science: dark matter, some as yet unknown type of particle.

 

 

EDit: I wonder if there's such a thing as anti-dark matter. :lightning:surprise::thumbs_up

 

 

:dogwalk:

 

 

 

CC

[Jay-qu]

I wonder if there's such a thing as anti-dark matter.

 

Of course there is. In the case of a neutral scalar the dark matter particle is likely its own antiparticle. In the case of the particle being spin half or vector boson it is possible that it has some charge under the weak force (or a new gauge group) that would be reversed for the antiparticle.

[coldcreation]

Of course there is. In the case of a neutral scalar the dark matter particle is likely its own antiparticle. In the case of the particle being spin half or vector boson it is possible that it has some charge under the weak force (or a new gauge group) that would be reversed for the antiparticle.

 

Your "of course there is" seems overly optimistic.

 

As you correctly imply, the answer depends on what the heck dark matter particles are! If they are non-relativistic dark particles (as commonly believed) it could be assumed there would exist anti-dark matter particles. Though, we would then have to explain (just as the anti-matter problem above) why there is much more dark matter than anti-dark matter, and/or, explain where all the anti-dark particles are hiding.

 

The actual literature on such is rather weak and speculative at this time.

 

If you have any good links I'd be interested in reading more about that stuff (whatever it is, or isn't) :lightning.

 

 

CC

[Jay-qu]

No I wouldnt say overly optimistic - you asked 'I wonder if there is such a thing' not implying that it exists in equal quantities as normal dark matter. Of course it is hard to speculate how it will manifest in the universe when we have no idea what the particle is - but from a purely particle physics standpoint, all particles have anti-particles.

[coldcreation]

No I wouldnt say overly optimistic - you asked 'I wonder if there is such a thing' not implying that it exists in equal quantities as normal dark matter.

 

Normal dark matter? There's nothing really "normal" about dark matter (cold dark matter, CDM), let alone anti-cold dark matter (ACDM?).

 

Did you have a source (or link) for you pervious post (the one that starts with "of course there is") relating to ACDM?

 

 

Of course it is hard to speculate how it will manifest in the universe when we have no idea what the particle is - but from a purely particle physics standpoint, all particles have anti-particles.

 

True. But in that case there's no antimatter/matter asymmetry then, is there. They're all accounted for. :lightning

 

It's a good thing ACDM doesn't interact with normal particles. Lucky for us.:thumbs_up

[Jay-qu]

Apologies for not being clear enough - by normal I mean some sort of WIMP particle and not some energy tied up in an extra spacial dimension, extra phantom universe or any other crazy theory of dark matter.

 

It is common knowledge and by definition that every particle has an antiparticle - but if you require a link:

Theory: Antiparticles (SLAC VVC)

[CraigD]

It is common knowledge and by definition that every particle has an antiparticle - but if you require a link:

Theory: Antiparticles (SLAC VVC)

While Jay’s correct (as I expect, him being one of our best-physics-educated posters), I think many of us are confused by the distinction between antiparticles and antimatter, and particles that are their own antiparticle.

 

Although, as the SLAC webpage explains, every particle technically has an antiparticle, every antiparticle is not considered antimatter. An anti-electron (positron, [imath]e^+[/imath]) is antimatter, and a very obviously different particle than an electron, having opposite charge. An anti-photon, on the other hand, is indistinguishable from a photon (it is a photon), and isn’t considered either matter or antimatter.

 

One simple rule is that only particles that are considered matter, and are not their own antiparticles, have antiparticles that are considered antimatter.

 

What particles are considered matter is somewhat vague. IMHO, hadrons – composite particles made of quarks and gluons, which include protons and neutrons, are. The electron, alone among its family of particles, the leptons, is. Some weird hypothetical particles may be.

 

Other people have their own view of what particles are matter – the category is not formally defined.

 

Hence regarding Jay’s answer of CC’s

EDit: I wonder if there's such a thing as anti-dark matter. :surprise::surprise::surprise:

Of course there is. In the case of a neutral scalar the dark matter particle is likely its own antiparticle. ...

I’d say that, for the reasons I give above, for dark matter that’s comprised of particles that are their own antiparticles, there’s no such thing as antimatter – though again, the distinction is vague and informal, more in the domain of linguistics than physics.

[prometheuspan]

matter and anti matter were not created in equal portions, and in fact the core problem is that the anti particles tend to have less mass.

 

99 percent of the matter in the universe did co-annihilate. That process however, due to the mass and energy differentials, always tends to leave some positive particles around.

 

A different way of saying this might be to say that anti matter had a weaker brane interaction, and so at the level where there is no "matter" or "anti matter" just quantum soup, positive quanta were favored because they interacted more strongly with space/time.

 

super symmetry is a neat theory, and the universe does tend to like symmetry, but, it also likes asymmetry to stir things up. Were it not so the universe would be a big empty massless abyss.

 

It turns out that the actual scalar fractals are ambiguously psuedo symmetric with clear asymmetry

otherwise the universe would freeze up from being too ordered, or instantly wind down, for being all of it whipped up out of nothing.

 

When you get down to it, its all just scalar fractal echoes of the original quantum gravity phase event.

There is no particles, they are composed of space time looping across branes.

 

Particles are the size and shape and regularity they are because thats the distance between branes.

 

The universe is agitated nothingness. Without asymmetry, the agitation would end instantly, and there would be no universe as we think of it.

 

You can't even have space as we think of it without mass... etc.

[CraigD]

matter and anti matter were not created in equal portions, and in fact the core problem is that the anti particles tend to have less mass.

Pan, you’ve just made a claim as it were common knowledge fact, when to the best of my knowledge, is completely contradicted by all but the most speculative, unconfirmed theories, and all of a vast amount of experimental evidence. One example of such an experiment is described in this 2006 UR Physics department article.

 

Can you provide any links or reference to back up this claim? If you can, you should have included them in your previous post – this is literally hypography’s #1 rule. If a science site allows posters to utterly fantasize, rather than supporting ideas with at least plans for experimental testing of them, especially when their ideas, it’s nothing more than an un-moderated geek gossip site. Though, with an all-volunteer moderation team, hypography can’t counter every such claim, and tend to let reasonable unsupported claims slide, your post is, in my administratorly (and thus, authoritative) opinion, far over the edge of acceptability.

 

So, either post some support of “anti particles tend to have less mass” (which, at very least, will teach you, and inform readers, that such an idea is radically counter to accepted theory and experimental evidence), or acknowledge that you’ve either made a mistake, or simply made the idea up.

:hyper:

PS: Do NOT post a mass of links only vaguely related to the subject, as you have done in previous posts. Post a single or a few links, quoting in the post the specific part(s) of the linked text that supports the idea of antiparticles having less mass than their counterparts.

[prometheuspan]

an, you’ve just made a claim as it were common knowledge fact, when to the best of my knowledge,

 

to the best of your knowledg. are you or are you not the same guy whos arguing from ignorance in the global warming thread?

 

you don't have any knowledge worth repeating, and i find your warning and your "foul"

note to be stupid and disgusting.

 

If you want to ask questions, ask. I'm not here to be whipped because i am smarter than you.

 

get it? **** off.

 

 

 

 

is completely contradicted by all but the most speculative, unconfirmed theories, and all of a vast amount of experimental evidence. One example of such an experiment is described in this 2006 UR Physics department article.

 

No, it isn't. Its assumed to be fact by assorted theories, which, btw, is all we have.

 

Can you provide any links or reference to back up this claim?

 

No, not after you foul me for not doing so to start with.

 

I'm just walking out of here.

 

You have repeatedly demonstrated that you have an intellect of maybe a 120 IQ and

that you aren't interested in knowledge, but personal petty drama.

 

 

 

If you can, you should have included them in your previous post – this is literally hypography’s #1 rule. If a science site allows posters to utterly fantasize, rather than supporting ideas with at least plans for experimental testing of them, especially when their ideas, it’s nothing more than an un-moderated geek gossip site.

 

You can ask me questions, or you can do some research yourself.

 

The way it would work if you had any idea who you are talking to is 5 of you would run

google and get back to the thread.

 

 

 

Though, with an all-volunteer moderation team, hypography can’t counter every such claim, and tend to let reasonable unsupported claims slide, your post is, in my administratorly (and thus, authoritative) opinion, far over the edge of acceptability.

 

Authority if real derives from attachment to truth. You aren't authoritative, you are just a bully carrying a grudge because i showed you to be an idiot propaganda artist on another thread.

 

So, either post some support of “anti particles tend to have less mass” (which, at very least, will teach you, and inform readers, that such an idea is radically counter to accepted theory and experimental evidence), or acknowledge that you’ve either made a mistake, or simply made the idea up.

 

Maybe you might notice that your attacking me and talking about me, not the subject.

 

Under such conditions, my interest in you and this forum has gone into negative numbers.

 

You are wasting my time.

 

I have a 180 IQ and i know what i know.

 

Your a muggle with a hard on to give me crap because i demonstrated you hadn't the first clue about global warming.

 

I'm not interested in playing your mind **** games.

 

 

PS: Do NOT post a mass of links only vaguely related to the subject, as you have done in previous posts.

 

gee, that bothered you in the global warming thread, did it?

 

 

Post a single or a few links, quoting in the post the specific part(s) of the linked text that supports the idea of antiparticles having less mass than their counterparts.

 

I don't take orders from pricks.

 

most other people in my situation don't either.

 

If you wanted something from me, you should have found a way to ask me for it,

rather than being a jerk and demonstrating to me why i'm only wasting my time here.

[CraigD]

to the best of your knowledg. are you or are you not the same guy whos arguing from ignorance in the global warming thread?

No. You may be confusing me with C1ay, who you accused of this, although I consider C1ay to be well informed on the subject, despite us disagreeing on may scientific and policy details on the subject.

 

I concur with the IPCC position on human-caused global warming.

 

In my post 700 MPH winds!? I did disagree with you claim that global warming denialism would result in storms with 700 MPH winds., and in Hypography’s requirement to back up claims, and a physics exercise for the reader, disagreed with your claim that hundreds of millions of years ago, magnitude 14 occurred every few months or so, and invited you to complete a fairly simple, AP high school to introductory college exercise in Earth science to better understand why your claims were scientifically silly.

 

I suspect you are emotionally upset by disagreement and requests to support you claims, and that this has caused you to become so confused you are unable to remember member names and posts, or reread them to refresh your memory. This sort of emotional lability is usually (pardon the wordplay) a liability in all parts of life – personal, academic, and professional – so I hope you’ll someday overcome it.

 

Despite warnings in the form of posts and infractions from members and moderators, including myself, you’ve refused to follow the rules you agreed to when you joined hypography. Because the enjoyability and informational value of our site depends on these rules, you will no longer be allowed to post here.