A new paper http://arxiv.org/abs/1107.1575, by one of the academics in my department at Warwick (different group), suggests a possible explanation of the matter/antimatter ratio problem.

An slightly more accessible explanation of the theory is given in the press release:
http://www2.warwick.ac.uk/newsandevents/pressreleases/galaxy_sized_twist/

I’m not very good at particle physics & general relativity, but is sounds an like an interesting hypothesis that can be tested.  I guess by correlating CERN data with the orientation of the Earth with respect to the Galaxy at the time.

Interesting speculation, but I personally don’t buy it.  This would suggest that galaxies which have opposite rotation would be comprised of antimatter. 
  I know what the standard comeback is for this criticism.  It’s “The galaxies are so far apart that this can happen”.  But I don’t buy this either.  We have too many observations of colliding galaxies.  With no apparent mutual annihilation events in evidence.
  If rotational twisting of space is the reason for this parity violation it has to be at some larger scale then galaxies.  (Hard to imagine but possible)

How can two have opposite rotation?  if one rotates clockwise as viewed from the top, then its anticlockwise when viewd from the bottom.

The labelling of galaxy spin as up/down is as abitrary as whether we switch the names of matter & antimatter.  By conventional big bang theories the matter/antimatter baryonic particles would have condensed out of the high energy soup before they began to collapse into galaxies and spin-up.  So the early Universe would have been symmetric.  Only now that we are in regions of space with significant gravitational twist is the symmetry broken.

I think there could be regions of the Universe that are predomenantly anitmatter, but our local matter region would be bigger than the local observable Universe.

Sorry for the delayed response. Been busy.

Yes you are right; we need to define what we mean by top and bottom of galaxies. I suggest the following definition:

It is pretty much accepted as Cannon that all spiral galaxies have at their core a super massive black hole. Maybe not the globular clusters, but the spiral ones. When this black hole is “feeding” it emits a one sided jet and we call it a quasar. This is really an outward manifestation of the orientation of the black hole’s magnetic field. Its magnetic moment, if you please.

I suggest that we call the side which emits the jet “top”.

Now, if the right-hand rule is universally true. (And I believe it is.) As viewed from the top all galaxies must rotate in the same direction. And as a corollary: the direction of rotation of a galaxy “clockwise or counter clockwise” will tell you which side will squirt out the jet if/when the black hole becomes active.

Or is my thinking on this muddled?

Yang and Lee and Madam Wu showed that CP invariance violation is demonstrated at atomic scales in the early 60’s. This would show that it is demonstrated in larger structures as well.

With regard to the antimatter question.  I misunderstood.  I reread the referenced paper.  Makes sense now.

How to know a parity symmetry violation when you see it:  http://en.wikipedia.org/wiki/The_Ambidextrous_Universe

The author implys that this wouldn’t work for antimatter galaxys, but if I’m not mistaken neither would Madam Wu’s experiment.

Was that en.wikipedia.org?

I just updated the link.  Should work now. 

I recently told a friend that I couldn’t get my DVR to stop blinking 12:00.  She suggested a way to fix it:  Cut a 2 inch long strip of black electrical tape and place it directly over the display.  That’s the kind of fix I like.

by the way, how does gravity behave w.r.t. antimatter?

do galaxies and anti-galaxies repel each other?

Eric would have fun with that one! Plasma streams between matter and anti-matter galaxies; how would they behave and what could we conclude from that?

vansig - 23 August 2011 03:06 PM

by the way, how does gravity behave w.r.t. antimatter?

do galaxies and anti-galaxies repel each other?

There is no theoretical basis for believing that antimatter behaves any differently then regular matter with respect to gravity.  But I’m no expert.

JimmyT - 24 August 2011 04:07 AM

There is no theoretical basis for believing that antimatter behaves any differently then regular matter with respect to gravity.  But I’m no expert.

True but then again ALL that we know about gravity comes from observation of Matter (or bodies we believe to be matter), and we know we don’t REALLY understand what Gravity or any fundamental force really IS to   Repulsion between Matter and Anti-matter would have a very alluring symmetry with electromagnetic charge being a kind of inverse of electromagnetic rules ware ‘like’ attracts and ‘different’ repels.  It would very nicely explain why we see no nearby Anti-matter or any annihilation reactions.  Though I find it hard to imagine this thought has not occurred to cosmologists before and been studied.

It’s not at all a hard thing to test if sensitive instruments are used, tiny amounts of anti-matter have been created in accelerators but I don’t believe any attempt has ever been made to weigh it.  This is probably a good test to run just to make absolutely certain were not missing some hugely important piece of the picture.

Impaler - 31 August 2011 07:59 AM

I find it hard to imagine this thought has not occurred to cosmologists before and been studied.

It’s not at all a hard thing to test if sensitive instruments are used, tiny amounts of anti-matter have been created in accelerators but I don’t believe any attempt has ever been made to weigh it.  This is probably a good test to run just to make absolutely certain were not missing some hugely important piece of the picture.

It has been imagined, but in fact it is extraordinarily difficult to study, because only single atoms of anti-hydrogen have thus far been created; and forces that would be able to contain antimatter for study are many many orders of magnitude stronger than gravity itself.

Well it looks like their is a testing scheme that will be conducted at CERN in the near future called AEGIS intending to do just this.  It seems to consist of firing a beam of anti-hydrogen and seeing if it’s deflected up rather then down.  http://aegis.web.cern.ch/aegis/experiment.html  My point was that the experiment is JUST a matter of instrument sensitivity in a controlled lab environment which is something researchers are very good at doing.  The ‘energetic’ part (making Anti-hydrogen) which is what’s expensive has already been done.