Antimatter and the big bang?

Cecil's Columns/Staff Reports
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This thread regards the anti-matter item: http://www.straightdope.com/mailbag/mantimatter.html and the supposed matter/antimatter asymmetry.

I’ve had a kind of an idea? call it a theory if you will… for several years now… about the big bang and this very topic, and of course, I have no proof or citations whatsoever on this idea that I will present very shortly.

My idea stems from the thought that the universe is NOT composed of matter and not antimatter. It’s composed of equal amounts of both substances. However, we arent able to see this, because it exists in another dimension.

Preposition 1: E = mc2
Energy = 1 piece of matter + 1 piece of equal and opposite antimatter.
Rule of conservation states that nothing can be wasted - ie. nothing can disappear. Hence for each and every piece of matter, we have an equal and opposite number of antimatter.

Preposition 2: The big bang caused matter to infinitely ‘expand’ outwards.
Assumption 1 based on Preposition 2: as antimatter shows the equal and opposite properties of matter, the same energy caused matter to infinitely ‘contract’ inwards.

Preposition 3: There are 4 given ‘known and proven dimensions’ x, y, z, and time that make up a space. However - in all modern popular physics theories, there exists ‘space’ for more. Hence this preposition = realized possibility for additional dimensions.
Assumption 2 based on preposition 3: given a container variable - lets call it k - that wraps the current dimensions(x, y, z, time)… The possibility of a dimension (or a 4-some set of dimensions) that contains the inverse of the visible and proven dimensions - 1/k. Hence: dimension lists x, y, z, time, 1/x, 1/y, 1/z, 1/time… in the inverted universe, time would flow backwards.

Conclusion from assumption 1 and 2:
In the visible set of dimensions (k), matter infinitely ‘expands’ outwards and anti-matter infinitely ‘contracts’ inwards - with this momentum separating the substances from self destruction. In the inverted dimensions (1/k), you have the very opposite thing going on - matter is infinitely ‘contracting’ inwards and anti-matter infinitely ‘expanding’ outwards.

What do you think about this idea? of course, no quotes citations etc blah blah blah because it was an original idea that I came up with while doing physics at college about 6 years ago. Didnt know about the m-theory or superstring theory back then (dont know the details of them even now…)

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It’s Friday evening, I got off work (I do nothing at work but read forum replies and so on… no work these days)… and I’m at a net cafe waiting for friends. By the way, just incase your wondering why it’s Friday and not Thursday, I’m currently in Asia (Korea to be more specific, in fact) and hence it’s Friday for me.

Anyway from the last post, there were follow up ideas that I had. Want to hear them? No? Too bad :)…

Anyway there were 2 basic follow up ideas that I had when I had thought of the first…

Idea 1:

What if time is not a fourth dimension and infact just an aftereffect of the expansion process? Does work well with the ever expanding matter plane and ever contracting antimatter plane idea. Doesnt work well with Idea 2 that I will present.

Idea 2:

But DOES the universe infinitely expand? Gravitational forces act at any distance less than the distance infinity, whence it’s energy is 0. However, momentum energy runs out given enough force. Right? So does there exist a distance infinity? Infinity is a concept that has yet to be proven. ‘close enough’ to infinity doesnt cut it to nullify the effects of gravitational energy. Hence this idea presents the universe as a great big ‘pulse-counterpulse’ thingy. The matter plane expands all the way until the momentum runs out, then contracts again. The antimatter plane does exactly the opposite, or in the 1/k dimension, does the same. So what is the big bang? It’s a regular occurance when all matter, and antimatter - due to the contracting process at 0, meet and become energy. Of course the great amount of energy within the oh-so-small amount of space is instable and so the big bang takes place again… get the idea?

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Look up 'gibberish" in a dictionary.

Sorry.

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Until you brought up other dimensions, it sounded like you meant matter and antimatter might dominate different areas of the universe. AFAIK we have no way to prove that, say, the Andromeda galaxy isn’t made of antimatter. (Maybe someone who’s a little better versed in physics can say if that’s right or wrong.)

In theory you have a point, but obviously if that were the case then the matter/antimatter ratio would be equal and it would all have annhilated itself shortly after the Big Bang.

That depends. When antimatter is pushed, does it move towards the force that’s pushing it? Does it follow antigravity and fly apart? Does it gravitationally repel normal matter?

So then you have a mathematical representation for the universe, and a mathematical representation for the reciprocal of the universe. The same variables (x,y,z) exist therefore there is not enough variety (not sure what the technical term is) here to require 6 variables to explain it. How does this help your theory? :confused:

The outward momentum is space itself expanding. The Big Bang occurred when the universe was a little bitty point. Even if antimatter somehow contracted from infinity (or a theoretical size limit) to that itty bitty point, it would still smash into matter along the way. Besides, isolated electrons and protons attract their antimatter equivalents due to opposite charges, therefore they would likely overcome the forces pushing them apart and smash together anyway.

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If you read the article, it explains why there CANNOT be equal amounts of matter and antimatter in the universe given cosmological observations. The galaxies and antigalaxies model has been propsed, but as there is no mechanis to keep the matter and antimatter apart it would lead to regions in which antimatter and matter would meet and anihilate relaeasing copious amounts of gamma rays; no such regions are observed (it’s all in the article). The symmetry between matter and antimatter is a broken symmetry (though in all probabilty CPT isn’t violated).

Prepostion 1: E = mc[sup]2[/sup] and the conservation of energy say nothing about antimatter, infact using these two principles alone it is possible for a postitron and an electron to meet and anihilate each other and produce two electrons (though other conservation laws make this impossible).

Prepostion 2: In big bang theory two co-moving objects no matter whether they are made out of matter and antimatter will recede from each other.

Prepostion 3: There are only 3 spatial dimensions, time is a temporal dimension. In relativity the universe is described by spacetime, a four-dimensional continuum with 3 spatial and 1 temporal dimensions. There is no observational evidence for any other spatial or temporal dimensions, thoguh some advanced physical theories do postualet there existance. the 1/x axis would be parallel to the x axis and certainly not orthogonal changing the axes in this manner would be a simple transformation, your not adding any extra information to the system).

Idea 1: time is a degree of freedom there’s no escaping that, though as I siad earlier it’s not a spatial dimension.

Idea 2: The bouncing ball model of the universe is unlikely given that all current cosmological observations suggest that the universe is expanding at an accelarating rate.

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That is extremely unlikely, as it would completely devastate the foundations of the General Theory of Relativity. G.R. may be imperfect, but it is not likely to be grossly false.

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It’s the extremely hypothetical and never observed negative matter that does this, not antimatter.

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Since antimatter behaves the same as ordinary matter, differing in electric charge, (which was what I thought in the first place) then the OP’s second preposition is flawed:

But then again it’s flawed either way since the expansion of the universe is space itself expanding, which can have only one outcome: distances between objects increase.

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Matter and antimatter behave identically with regards to gravity. This is both theoretically predicted by every major variation of the Standard Model and supported extensively by experiments. Negative matter, which has mass less than zero, is occasionally postulated, but mostly just for “what if” purposes, not because there’s any real reason to believe it should or does exist. It would have a number of interesting properties: If it’s charged, for instance, then like-charged particles of negative matter would all clump together, since a repulsive force would lead to an attractive acceleration, and you’d get objects with truly insane charge densities. But if you let go of a piece of negative matter in a gravitational field, it would still fall downwards like any other piece of matter, since the mass comes into the equations twice there and the minus signs would cancel.

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And what, pray, are the inertial characteristics of this hypothetical “negative matter”?

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How can there be an imbalance and at the same time, CPT not violated? I dont get this… it has to be SOMEWHERE, right?

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A matter-antimatter imbalance is only a CP violation, not a CPT violation. In fact, CP violations have been observed in the laboratory: Some particles such as the long-lived neutral kaon (which is its own antiparticle) have two different decay paths, one the matter-antimatter reverse of the other, and one decay path is favored over the other by about a part in a thousand. If CPT is valid (and it had darn well better be), then this implies that there is also a T symmetry violation in such systems, but T symmetry is much harder to test directly in the lab.

John, since inertia is proportional to mass (indeed, one may even say that it’s synonymous with mass), an object with negative mass would have negative inertia. So if I had an object with a mass of -1 kg and put a force on it of 1 N to the right, that object would then accelerate at 1 m/s[sup]2[/sup] to the left. And yes, I’ll be the first to agree that this is weird. But as I mentioned above, there’s no reason to believe such stuff actually exists, so don’t get too worried about it.

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There are will soon be ways to experimentally preclude negative matter. Assuming modern physics is at all on the right track, gravitational waves exist (and should soon be found). Without negative mass, the simplest form of gravitational wave is something called quadrapole radiation. (As the name implies, gravitational waves require the movement of at least four pieces of matter.) With negative mass, the simplest wave would be a dipole wave, which requires only two pieces. If we do not detect dipole radiation, then negative matter is, at the very least, quite rare.

In fact, I would think that one could show, under fairly broad conditions, that negative matter can not exist. From the perspective of theoretical physics, the biggest difference between gravity and electromagnetics is the existence of oppositely signed sources for the latter and not the former. That constraint has all sorts of ramifications, such as a “graviton” being spin 2. (A graviton would be the propagator of the gravitational force, like a photon is the propagator of an electromagnetic force.) I don’t know that anyone has worked out all the theoretical implications of negative matter, since I never heard of it before this thread and I studied GR, but clearly all theories uniting gravity with the other forces are predicated on the assumption that negative mass does not exist. I would hope that one could show some experimentally falsifiable prediction based on the existence of negative mass. Of course, since the big struggle with these theories is coming up with any experimentally verifiable fact, perhaps not.

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I mentioned earlier the basic conflict between GR and antigravity, but I didn’t explain it, so here goes:

Consider an empty spaceship at rest. In the center of that spaceship is a sphere of negative matter, floating in zero-gee. Now accelerate the spaceship “up”-ward. What does the negative matter do?

As far as I can tell, without invoking magic, it’s going to fall “down”. Even if it has negative inertia.

So the Principle of Equivalence is exploded, and G.R. is completely and utterly spifflicated.

Me no likey.

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No… The negative matter sphere has to rise up faster than the space ship does, unlike normal matter which falls down. When you hit the accel on ur car, do you jerk forward? I jerk backward, and I’m made from NORMAL matter mind you.

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No, Kennedy is correct. Picture a transparent spaceship with you, the observer, on the outside looking in. The spaceship accelerates to your left. The hunk of negative matter that was sitting in the middle of the spaceship stays still, because no force is acting on it. From the perspective of your evil twin, 87mikj, who is sitting at the right end of the spaceship (your right hand), the hunk of negative matter appears to accelerate towards the rear (your right) of the spaceship.

The principal of equivalence states that 87mikj can’t tell the difference between the affects of acceleration and gravity. So, imagine that instead of the spaceship accelerating, the spaceship stays in place while a planet exerts a gravitational force to the right of the spaceship. Everything seems the same to 87mikj, except that the hunk of negative matter starts accelerating to the front of the ship. Thus, negative mass violates the equivalence principle.

Except that the equivalence principle could be restated explicitly stating normal matter, or even reworked to account for the four possible combinations of gravitational source and observed mass. GR would then still be a possible theory.

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Negative matter is still consistent with the Equivalence Principle. If you’re in a spaceship accelerating forward, the negative matter will appear to fall “down”. And if you’re standing in a gravitational field, the negative matter will still fall down. One doesn’t even need to make the laws case-by-case for this to work. Any theory of gravity, from Newton to Einstein and beyond, will have negative matter falling the same way in a gravitational field as normal matter. The Earth, say, would exert an upward gravitational force on a piece of negative matter, rather than the typical downward force, and that upward force would then cause the negative matter to accelerate downwards.

As for gravitational waves, quadrupole radiation does not, despite the name, require four objects. All it requires is a varying quadrupole moment, which is almost impossible to avoid if you have masses moving relative to each other. The simplest source of gravitational waves is just two point masses orbitting each other. And while detection of dipole gravitational radiation would be strong evidence for the existance of negative matter, lack of detection would only prove that there are no star-sized chunks of negative matter in our vicinity, a fact in which we can already be fairly confident. But that’s a far cry from proving that none exists at all, and even miniscule amounts could be very significant.

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No your wrong. From the assumption that the zero gee chamber is a vacume, which was the assumption your calculations took, it doesnt prove squat that negative mass violates anything. You cant prove anything with 0 force… 0*x = 0 even if x is negative. duh. In my calc, I assumed air present - hence they ‘move’ one direction providing frictional forces in that direction, and the negative mass move in the other.

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No.

“SlowMindThinking” and I did make a mistake, but it is the mistake that Chronos correctly describes. We are correct that any object, whether of posititive or negative mass, falls “down” in an accelerating frame, but we forgot to consider that, because the negative signs on the force of gravity and the negative sign on the acceleration resulting from a force acting on a negative mass cancel each other out, negative matter also falls “down” in a gravity field.

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Chronos is right, that’s what I get for trying to think at work. I’ll have to stop that.

As far as waves go, Chronos is right, but not quite fair. The negative mass star would not have to be nearby. A dipole signal would be rather easy to pick out. (If anyone were looking.) Also, gravitational waves do not attenuate, so sources of gravitational waves can be far away by almost any standard. That is one reason GR wavers considered the possibility of detecting waves from a most unlikely source - the collision of two black holes. I stand by my statement that if there are no negative mass stars with detection range, then negative mass is rare. Of course, that assumes we can detect any reasonable number of gravitational waves at all.

You can get gravitational waves from just one point mass, not that it will ever happen. (You could, for example, shake one.) To be more precise, what I should have said was that the quadrapole terms are the simplest term when mathematically describing graviational waves in a common formalism. In analogy with electromagnetism, they can be pictured by certain motions of four point masses.