How can we know there is antimatter world somewhere in universe without reaching there? and also how i s it guaranteed matter world dominates over antimatter world. I wonder is there answer to this question

I'm absolutely hopeless at these sort of questions, but i remember watching a tv programme about the universe on this subject, i can't remember that much about it or the right words to choose here, but matter and anti-matter attract each other ( i think? ) and cancel each other out, there was more matter of which was left over from the fight which in turn formed all the mass in the universe.

PMB is more the man to answer on these subjects.

i remembered the show just now. was it on national geographic? did it feature michio kaku at the end??
as far as i remember, they showed an animated picture of a process taking place in early universe where there was approximately one matter extra per billion(may be a larger figure) matter antimatter pairs.
and the light you are taking are the resulting gamma rays emitted from the annihilations.
you are absolutely correct(i think) and it is from studies of these gamma rays that scientists conclude that the dominance of matter should be traced to this asymmetry in the early universe.
and the existence of antimatter (made of antiparticles) is necessary as feynman has explained "to wed quantum mechanics with relativity."

michio kaku,

His he oriental looking?, i think he an absolute genius if its the guy i'm thinking about.

Welcome to Explorations in Science with Dr. Michio Kaku
wish u a good experience.........

Ricky,

Yes thats the guy i was thinking of, i watch programmes about the universe alot and see him talk about things, i think he is fantastic!

glad to know.