# Antimatter self.

1. Feb 8, 2014

### Manraj singh

I read that every particle in the universe has an antimatter form of itself. Does that mean there exists an antimatter form of ourself? If so, where is this antimatter form of ourself? This question might be stupid, but I'm just curioous.

2. Feb 8, 2014

### ZapperZ

Staff Emeritus
Where exactly did you "read" this? Note that it is our policy in this forum that you cite your source clearly.

Secondly, the idea on the formation of our universe is, based on our understanding of current physics, that there should be equal amounts of matter and antimatter created. However, that is not what we observe now, that there is a severe imbalance of matter over antimatter. The reason for this is still the subject of intense study. But what this means is that you do not have an antimatter form of yourself somewhere else.

Zz.

3. Feb 8, 2014

### Staff: Mentor

For each specific kind of fundamental particle, there is a corresponding kind of particle which we call its "antiparticle" (allowing for some particles which are their own antiparticles, e.g. the $\pi^0$).

This does not mean that for each specific object (either a fundamental particle e.g. an electron or a non-fundamental object e.g. you) there is a corresponding "anti-object."

4. Feb 8, 2014

### nkalanaga

IF the universe is infinite, or IF there is a corresponding antimatter universe that is infinite, then every possible configuration of matter will have an antimatter counterpart. In that case, yes, somewhere there is an antimatter version of you.

If this universe isn't infinite, or doesn't, somewhere, contain the "missing" antimatter, and if there is no corresponding antimatter version of this universe, then there probably isn't an antimatter version of you.

In any case, the "where" would be very difficult to answer, as one would have to search an entire universe to find it.

5. Feb 8, 2014

### ZapperZ

Staff Emeritus
What current physics concept did you base this on to arrive at such a conclusion? And what parameter here that you are characterizing to be "finite" or "infinite"? The size?

Please provide proper sources.

Zz.

6. Feb 8, 2014

### DarthMatter

Think of it in terms of sand and sandcastles. Someone in the (fictional) universe which consists only of sand* comes up with the observation that there is exactly as much sand as anti-sand (or proposes there should be, due to some theory). This doesn't mean a specific sandcastle has an exact counterpart made of anti-sand, just that you *could* theoretically make an exact anti-sand-copy of each object of the part of the universe which consists of sand.

*or so they thought, before anti-sand was discovered

Last edited: Feb 8, 2014
7. Feb 8, 2014

### nkalanaga

Zz: Basic statistics. There are a finite number of particle types, and a finite number of particles in a human-mass object. Therefore, in an infinite universe, any possible combination of particles in such a mass will have to reoccur.

If our universe is infinite, and the "missing" antimatter is elsewhere in the universe, then there has to be an infinite amount of it. Thus, any possible combination can be found there.

If the antimatter is not in our universe, but segregated into a "mirror" universe, and that universe is infinite, then the combination can be found there.

If our universe is not infinite, then it is possible that there are more possible combinations than particles to make them, and there is no guarantee that a given combination can be found.

8. Feb 9, 2014

### ZapperZ

Staff Emeritus
That doesn't work in this context. Unless you are claiming a steady state universe, your idea has huge amount of holes if we invoke the current understanding of the formation of our universe, whether it is "infinite" or not. You have to show how, from the matter-antimatter formation in the early universe, that these matter and antimatter would spontaneously segregate themselves and are able to maintain these segregation (despite their mutual attraction), and then migrate to the distant parts of the universe away from what they are attracted to. There are no existing, published theories that would support such a thing.

That is what I am asking for proper references for. Otherwise, this will be a speculative idea in violation of our Rules.

Zz.

9. Feb 9, 2014

### 256bits

The largest combination of particles one can have so that it is possible to have another copy is N/2 where N is the total number of particles, in which case other copies using less than half the number of available particles are non-existant since all the particles have been accounted for in the 2 copies.

Mathematically, I am not so sure if the above statement can be considered true, since the combination of particles together with the number of combinations just might exceed the total number of particles.

I suppose it could be proven one way ot the other by someone adept at infinities.

10. Feb 9, 2014

### DarthMatter

I think even if the universe is infinite there have not necessarily to be exact copies of each existing object. As an easy example at inifinities, consider the infinite subsets $\{1,3,5,7,9,11,13,\dots \}$ and $\{ 2,4,6,8,10,12,14,\dots \}$ of the natural numbers. Both have infinite many members, but no common members.

11. Feb 10, 2014

### Khashishi

Manraj singh, every fundamental particle has an antimatter counterpart, (except for photons, which are their own antimatter counterpart). For example, electron and positron. Proton and antiproton.
This doesn't mean that a large composite object like yourself has an antimatter counterpart. The standard model only applies to subatomic particles. At that scale, we can assume each particle exists somewhere in the universe, but when you start talking about larger and larger conglomerates, these specific patterns don't necessarily exist anywhere.