## Matter vs. Antimatter

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sonickrahnic
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### Matter vs. Antimatter

OK, this may get a little mathematical and theoretical but I need to get this out there. So, we live in a matter intensive universe, where we all exist because we consist solely of matter. If there were an existence of antimatter, that is, matter that is equal to but equally inverse to our mass, we would annihilate. This means that if there were any negative representation of our mass in the same space as our own positive representation, mathematically, it would balance out to a null representation. This means that the simple idea of zero means that there must be a realisation of the existence of negativity within our physical universe. I can accurately exhibit this idea by gravitation. In our matter intensive universe, gravitation is measured in Newtons. One Newton means that one unit of gravitational force is exhibited by an object which attracts another object. For there to be a negative Newton there needs to be a force which exactly counteracts that postive force. So, one negative Newton does not mean that there is any less force exhibited, but in a totally different numerical representation, there has to be an equal representation of that force, only inverse. So, for there to be a zero, there has to be an equal and opposite force resisting the original force creating that nullity. This is Newton's third law. But, in examining this idea, which I am in no way a scholar, I realize that for such a concept to exist, there must be a universe parallel to our own that exhibits exactly opposite tendencies of our own universe. And for such a universe to exist there must be some barrier that separates the universes so that nullity does not occur. But how do we detect such a universe when our encountering such a universe involves our annihilation upon contact? Sorry if this seems patchy and uninformed. I just had this idea while wandering drunk from 7/11 to home. I just wondered about the existence of zero as simply a placeholder for the value that represents the nullity created by the meeting between positive and negative. If there is a zero, I theorized, there has to be both a positive, which we live in, and a negative, which is yet to be discovered. And yes, I am aware of the creation of antimatter particles contained within a strong magnetic field. But these particles were inevitably annihilated upon contact with actual matter. What I am theorizing here is the existence of a universe directly parallel with our own that is directly inverse to our own. I do not know at this time if I am being clear but if anyone has anything to add, subtract or simply corroborate, please do. I am pretty in the dark here.
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Tupolev
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### Re: Matter vs. Antimatter

sonickrahnic wrote:If there is a zero, I theorized, there has to be both a positive, which we live in, and a negative, which is yet to be discovered.

Not necessarily, I think. Your logic concludes that, under certain physical models (in this case, force), a positive thingy and a thingy of equal size but negative sum to zero.
This does not imply that for all zeroes there is a real positive and negative component, nor does it imply that all positives must be balanced out by some negative, nor does it imply that zero cannot exist as a thing if such conditions are not met.

Xanthir
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### Re: Matter vs. Antimatter

You are assuming that the balance of matter and antimatter is a fundamental rule. It may not be - at least in our universe, it's clearly not, as we have experimental evidence of some physical processes that produce more matter than antimatter. This is certainly not any kind of mathematical law based on the existence of zero, any more than the existence of zero means that the amount of blue and orange in the universe must be balanced (as they are clearly opposite colors).

If we were to find a universe where the balance of matter/antimatter was opposite, we could still interact with them via light, radar, magnetism, etc. Light is its own antiparticle, and so doesn't really care whether the stuff it's interacting with is matter or antimatter. We just couldn't touch anything over there.
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doogly
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### Re: Matter vs. Antimatter

antimatter has positive mass.
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Kayomaro
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### Re: Matter vs. Antimatter

Well it makes sense on some levels, and makes no sense on others. For one, all matter particles have an antimatter equivalent. We all know that. (And if you didn't before, now you do.) But what if the forces that they exhibit were opposite as well? For instance say there is a hydrogen atom. You've got your one proton, and one electron. The strong and weak forces are there, as is electromagnetism due to charges. Gravity as well, because of the mass. But an antimatter hydrogen atom is inverse to your regular hydrogen atom, being exactly opposite? Seems a little strange if the forces acting on it are the same. But if we theorize that the forces antimatter would exert on it's surroundings were opposite as well, you would end up with a double negative. That lets antimatter interact with antimatter in the same way that matter interacts with matter, but giving a simple(vastly oversimplified) explanation to why they would cancel each other in all senses that I can think of.

You theorize that a separate and opposite universe must exist for our own to exist right? That's a good theory, not gonna lie. But in order for both of them to exist and not annihilate each other, there would have to be another force much stronger than any we've discovered so far in order to keep them apart. Now it could just be that the positive mass of antimatter works with the double negative i theorized and causes an anti-gravity field keeping matter and antimatter separate... But I've never heard of such a thing. I'm really just thinking on my keyboard here in all honesty.
Getting into the whole idea of using numbers: Zero is a condition of everything being equal. We agree on that? If everything is equal, it only follows that you need to have equal opposites. Still pretty simple. So if you have no apples, you have 1 to infinity apples, but also -1 to -infinity apples? Little bit different now, isn't it? I've got to agree with Xanthir. Zero is a result of equals and opposites canceling each other out, but it doesn't necessarily have to be that way.

And as food for thought.. If there really is a positive that we live in, and a negative we haven't discovered, what stops us from living in the negative and not having found the positive?

Xanthir
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### Re: Matter vs. Antimatter

Kayomaro wrote:Well it makes sense on some levels, and makes no sense on others. For one, all matter particles have an antimatter equivalent. We all know that. (And if you didn't before, now you do.) But what if the forces that they exhibit were opposite as well? For instance say there is a hydrogen atom. You've got your one proton, and one electron. The strong and weak forces are there, as is electromagnetism due to charges. Gravity as well, because of the mass. But an antimatter hydrogen atom is inverse to your regular hydrogen atom, being exactly opposite? Seems a little strange if the forces acting on it are the same. But if we theorize that the forces antimatter would exert on it's surroundings were opposite as well, you would end up with a double negative. That lets antimatter interact with antimatter in the same way that matter interacts with matter, but giving a simple(vastly oversimplified) explanation to why they would cancel each other in all senses that I can think of.

Note that antimatter doesn't cancel matter, in the sense of "bring them together and they disappear". It's opposite in the sense that if you reversed the charges of all particles, flipped us into a mirror universe, and then reversed time, a universe made of antimatter would look exactly like our current universe of matter.

Also, for some reason when you touch them together they mutually annihilate and release all their energy. It's all positive energy, so rather than cancelling it just adds together like normal and creates a giant explosion.

And as food for thought.. If there really is a positive that we live in, and a negative we haven't discovered, what stops us from living in the negative and not having found the positive?

Definitions. We like positive numbers better, so we define ourselves to be positive.
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doogly
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### Re: Matter vs. Antimatter

Actually, what Xanthir just described is a CPT transformation (charge, parity, time). Under one of those, everything maps back into itself. It is an identity transformation. (this is a deep and potent theorem, one of the fanciest in quantum field theory). To get from matter to antimatter, you do a CP transformation. This isn't a symmetry of the universe, which is nice, because we like living in a world that has more matter than antimatter. (the decision to call the one there is more of matter and the one there is less of antimatter is of course pure convention).
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sonickrahnic
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### Re: Matter vs. Antimatter

Kayomaro wrote:I'm really just thinking on my keyboard here in all honesty.

I think thats what I was doing. I actually did not remember posting that until reading it just now. I tend to have a lot of time to myself to think (and drink apparently) and I come up with some pretty wacky shit. I know most of what I said probably does not make sense but I have enjoyed reading all of your answers thus far. Very interesting, this CPT transformation. So, now, if I understand your description correctly its a recursive transformation, always coming back to the origin, like a circle, or is it's progression more like that of a Mobius band, twisting once before coming back to the origin? I realize I must be quite confusing. I have come into a sudden taste for math and science a little later in life than most (I'm 23 and have only really been interested in math and pure science for about 2 years) so my understanding of most concepts is foggy. But I make connections here and there and I get an idea and it just grows until I have to find something concrete out about it. So thanks for all your replies, they have really made me understand a lot more about the physical world, although I know that they barely scratch the surface of the established knowledge out there.
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douglasm
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### Re: Matter vs. Antimatter

doogly wrote:Actually, what Xanthir just described is a CPT transformation (charge, parity, time). Under one of those, everything maps back into itself. It is an identity transformation. (this is a deep and potent theorem, one of the fanciest in quantum field theory). To get from matter to antimatter, you do a CP transformation.

Wouldn't this imply that a T transformation (i.e. reversing the direction of time) also converts between matter and antimatter? Makes me wonder how valid it might be to view matter-antimatter annihilation as a particle simply reversing its course in time - when you see an electron and positron collide, they're actually both the same particle but one of them is traveling into the past, and the energy produced is associated with the reversal rather than mutual destruction.

Scyrus
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### Re: Matter vs. Antimatter

Woah woah, I always thought that antimatter was exactly equal to normal matter save for charge. Both have the same properties for everything else, right?
Positive mass, same fundamental units and forces, inability to go FTL, etc.

Also:
Xanthir wrote:You are assuming that the balance of matter and antimatter is a fundamental rule.

Is this not what the law of conservation of energy means? I always found that one particularly "fundamental". There must be an equal ammount of matter and antimatter in the universe, because the ammount of energy, be it in it's pure form or condensed into (a)matter, must be constant. The same holds true for matter and antimatter, because they have to exist in equal ammount in order to be converted to/from energy, which must be constant.
We say there are almost none or completely none particles of antimatter based on observation only. What if the antimatter simply got clumped up on black holes? We know for certain the distribuition of matter in the universe is certainly not homogeneous.

What the OP suggested was that there might be a parallel universe holding all the antimatter that isn't here, basically, a universe equal to our own except the matter-antimatter ratio is reversed. But wouldn't this imply that conservation of energy applies to both universes (or more) rather than just one?

BlackSails
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### Re: Matter vs. Antimatter

doogly wrote:Actually, what Xanthir just described is a CPT transformation (charge, parity, time). Under one of those, everything maps back into itself. It is an identity transformation. (this is a deep and potent theorem, one of the fanciest in quantum field theory). To get from matter to antimatter, you do a CP transformation. This isn't a symmetry of the universe, which is nice, because we like living in a world that has more matter than antimatter. (the decision to call the one there is more of matter and the one there is less of antimatter is of course pure convention).

Ive never heard of an experiment actually demonstrating T violation. I know CPT is mathematically true, but is is experimentally so?

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### Re: Matter vs. Antimatter

Scyrus wrote:
Xanthir wrote:You are assuming that the balance of matter and antimatter is a fundamental rule.

Is this not what the law of conservation of energy means?

If they both have positive energy, conservation of energy doesn't have anything to say about their proportions. It's happy any way your want to mix them. Other symmetries are not so pleased, but they are not so fundamental, a fact made evident by the asymmetry between matter/antimatter.

BlackSails wrote:Ive never heard of an experiment actually demonstrating T violation. I know CPT is mathematically true, but is is experimentally so?

There are theoretical grounds for imagining a small deviation from CPT is possible. So far it's held up, although I just found some preliminary MINOS results that are quite interesting.

This guy's page at Indiana U seems to be the authoritative clearinghouse. I like to visit it from time to time to see what's up. He's done a lot of the theoretical work on what CPT violation would look like.

There's some experiments at Princeton.
http://physics.princeton.edu/romalis/CPT/

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xkcdfan
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### Re: Matter vs. Antimatter

Scyrus wrote:Woah woah, I always thought that antimatter was exactly equal to normal matter save for charge. Both have the same properties for everything else, right?

So what do you think the difference is between a neutron and and anti-neutron?

doogly
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### Re: Matter vs. Antimatter

Thinking of antimatter as matter moving backwards in time was something Feynman first observed, I believe.
CP violation is observed not just cosmologically (where it is observed a lot) but also directly, first with kaon decay. It is very clear it's not a real symmetry.
CPT is pretty great. One important thing is that if you imagine violating CPT, you also have to violate Lorentz symmetry. Plenty folks are happy to violate both in some special regime, but still, realize the cost is high.
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Scyrus
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### Re: Matter vs. Antimatter

xkcdfan wrote:
Scyrus wrote:Woah woah, I always thought that antimatter was exactly equal to normal matter save for charge. Both have the same properties for everything else, right?

So what do you think the difference is between a neutron and and anti-neutron?

One is made of quarks and the other is made of antiquarks, who are only opposite in sign. So, essentialy, the diference are +/- signs.

I just thought antimatter belonged to simple C-symmetry, I had never mixed it with time in my imagination.

Im am pretty clueless on the subject, can someone define to me the exact properties of antimatter? Any research I do ends up with discrepancies in definition, or maybe I just don't understand it.

doogly
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### Re: Matter vs. Antimatter

Parity is the other thing. It's important for handedness.
LE4dGOLEM: What's a Doug?
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