Correct there is no way we can directly test if galaxies are composed of matter or anti matter. However we can verify all observable ones are made out of same type of matter because they all share a common gravitational property.

However if the gravitational forces of matter and antimatter are repulsive as you suggested at http://hypography.com/forums/alternative-theories/18910-the-dominium-model-by-hasanuddin-2.html (“Test of the Dominium premise that you yourself defined gravitational repulsion between matter and antimatter)
we should see the gravitational effects of this repulsion in the movement of an antimatter galaxies when it interacts with those made up of matter. However all observable galaxies appear to share a common link in a gravitational attractive forces associated with their mass. If they did not it would be detectable by their relative motion with respect to each other. Therefore we can conclud that all observable galaxies are made up of the same type of matter.
Jeff

I like this subject. However I respectfully and absolutely do not agree with you to make conclusion based on this statement, “because no galaxies or intergalactic clouds of antimatter have yet been detected that have the ability to offset the observed quantity of matter in the universe. ” I disagree because this is an unknowable assertion. The truth is we possess no method of directly testing the composition of distant galaxies.

The hot new cosmologic model, the Dominium, it is deductively shown that matter and antimatter twins of one another. Antihydrogen has been synthesized by scientists at CERN. If they succeed in mapping antihydrogen’s spectral signature and if that signature perfectly matches common mass-based hydrogen, then it would be near impossible to look up into the Earth’s sky and know with any degree of certainty which galaxy was composed of matter and which antimatter. The antimatter one’s would be organized in a similar fashion as our own, but equivalent antimatter reactions would be going on. For example, four antihydrogen=1 atoms antifuse to form one antihelium=4 and two electrons. In such cases it would be expected that the resulting photons would be exactly the same frequency, wavelength, and speed as photons made in common fuse.

See the whole model as it is unfolded and debated at: http://hypography.com/forums/alternative-theories/18910-the-dominium-model-by-hasanuddin.html And please join in.

Check out my blogs at
http://www.abassterinternational.blogspot.com/
I just updated them with new content.

Wishing you a happy day,

Abas.