[David Mannino]

David Mannino  asked the Naked Scientists:
   
Hello Chris,

I hit the backlog of newbielink:http://www.thenakedscientists.com/HTML/podcasts/ask-tns [nonactive] off iTunes and loved it, although I never did find out why baboons bums are red...

Anyway, the answer to question I have answer can only be speculative but here goes:

1: The universe is composed of primarily matter and not antimatter.
2: Antimatter and matter from our perspective, doesn't like each other.

Could our part of the universe be a bubble of matter while other parts are separate bubbles of antimatter? If so, could that be a good reason why the universe is expanding (i.e. dark energy)?

What do you think?

[graham.d]

I don't think anyone knows. The matter-antimatter imbalance is really a mystery and the known evidence seems to suggest that there was a huge annihilation of matter and antimatter but there was an asymmetry which meant that, after this, there was mainly matter left. More recent theories may allow for the possibility that, for example, we exist on a 4 dimensional brane of a 5 (or more) dimensional universe. You could consider this as a bubble, which is some ways more descriptive, and that other branes may have other manifestations of the underlying structure that may be a different balance of the types of particles present. So it is possible you may be right.

[David Mannino]

Unfortunately I am not that well informed about string theory in general but to clarify I meant more in a physical sense in our own dimensions. As if the Milky Way galaxy were made of matter while the Andromeda galaxy were made of anti-matter. I of course don't mean something that close in distance or even anything as small on this scale as two galaxies. I meant more of something like the Milky Way, Andromeda, Sagittarius Dwarf Elliptical galaxy, and Canis Major Dwarf galaxy - to pick 4 at random (on the internet, it always takes five minutes of googling to take 4 names at random) - which would be made of matter and maybe the upper leftish sort of area in the 'Cosmic Zoom Lens' to be made of antimatter.

These are all arbitrary picks mind you but the concept still holds if you assume that the Big Bang threw out both matter and antimatter at random as a bias for one doesn't make much sense to me (then again neither does it for everyone in this field - which is more/less the point).

This behavior would only make sense to me at this point if...

A
1. Matter and antimatter were thrown off pretty much at random, in all directions (although maybe not completely at random - see B)
2. Matter and antimatter mixing created the energy for the expansion in the first place (I have no idea how this works, just bear with me here).
3. Matter and antimatter which had happened to be in proximity with each other in the 'cloud' encouraged separation further.

B: Contains A: but with a minor difference - particularly shape. Matter and antimatter were expelled with some sort of patterning, there are many ways this could happen in theory (to my mind anyways).
- Related to A1. above: Matter and antimatter not at random but separated into two halves (I don't like this one but I include it for completion)
- Related to A1. above: Separated out with a bias in two directions but not always that localised.
- Related to A1. and A3. above: Spread out with a patterning like spokes on a bicycle, but in all directions. Not that much different but much a more pleasing visual.

C: The universe doesn't actually exist and we are just kidding ourselves (this is the only one that almost seems to make sense after thinking about this too hard).

[yor_on]

To make that idea work you would have to count in expansion and then define it as something like "Where the light won't ever reach us from, due to expansion."
Then you also would need to explain why we don't see 'energy' cooking at the 'horizon' of our possible 'light space'. One might argue that we can't see 'far enough' though? The 'energy' I'm talking about being the positive 'rest product' of matter and anti-matter annihilating each other.

I don't expect it to be so myself though.

[peppercorn]

"Matter and antimatter were thrown off pretty much at random, in all directions (although maybe not completely at random"

If truly at random there would be almost complete annihilation very quickly after the 'Bang'. The regions of remaining mater or a-m would be far too small to cause galaxies, etc.

For this to work there would need to be some physical mechanism to island-off regions of matter from a-m.

The more simple, structure forming explanation, that some (unproven so-far) break in symmetry caused a massive slew towards creation (or at survival) of what we now call 'matter'.

[QuantumClue]

David Mannino  asked the Naked Scientists:
   
Hello Chris,

I hit the backlog of Ask the Naked Scientist off iTunes and loved it, although I never did find out why baboons bums are red...

Anyway, the answer to question I have answer can only be speculative but here goes:

1: The universe is composed of primarily matter and not antimatter.
2: Antimatter and matter from our perspective, doesn't like each other.

Could our part of the universe be a bubble of matter while other parts are separate bubbles of antimatter? If so, could that be a good reason why the universe is expanding (i.e. dark energy)?

What do you think?

Oh yes, completely. Scientists have even postulated the existence of entire anti-galaxies! Nice question.

[David Mannino]

Anti-galaxy...interesting, I like the sound of that  []

[peppercorn]

Anti-galaxy...interesting, I like the sound of that  []

I wouldn't pay it a visit though, if I were you.

[CliffordK]

Anti-galaxy...interesting, I like the sound of that  []

I wouldn't pay it a visit though, if I were you.

In theory you could have unlimited power if you could harness it, and get some moved to a "normal matter" system.  The space traveler's dream!!!

[David Mannino]

Anti-galaxy...interesting, I like the sound of that  []

I wouldn't pay it a visit though, if I were you.

In theory you could have unlimited power if you could harness it, and get some moved to a "normal matter" system.  The space traveler's dream!!!

Well, newbielink:http://http://en.wikipedia.org/wiki/Laws_of_thermodynamics [nonactive].